I posted a couple of months ago about recurring misfires on a 2008 RS4. Only 9500 kms on it after 1 year of ownership. Not a daily driver and certainly not babied when i get it out on the highway. After 4 visits and fixes ranging from vacuum lines, to plugs, to coil packs (and 1 DRC repair) i finally pushed hard enough for my local dealer to elevate the issue to Audi technical.

Factory support recommended removing the intake and testing/replacing the injectors. As i suspected, once the manifold was off and the intake valves exposed they called me to let me know that they would have to be cleaned.

I stopped by the dealer this morning with my point and shoot to get some documentation, and it looks like they are using a combination of solvents and walnut shell blasting to clean the valves.

Photos here: http://web.mac.com/braddy/iWeb/Site/RS4%20valves.html

Thanks for posting the pics. I know what its like. Did they have to replace any injectors or did they just test them?

This is going to be far more common than DRC problems. No matter how the car is driven, no matter the Tier 1 fuel, no matter what oil is used, there will be buildup on FSI intake valves.

Thanks for posting the pics. I know what its like. Did they have to replace any injectors or did they just test them?

This is going to be far more common than DRC problems. No matter how the car is driven, no matter the Tier 1 fuel, no matter what oil is used, there will be buildup on FSI intake valves.

Yes, they are replacing injectors. They have also sent Audi Technical a sample of the deposit material for analysis.

I think we can all agree these problems appear to be widespread with FSI engines. It's even detailed as an issue in VW's patent on direction injection technology. They've simply not gone far enough in reducing the oil dilution and clearing the resulting oil vapor in gas recovery system. My service advisor has told me that they have seen this issue on 2 other 4.2 FSI engines (including an R8) as well as many of the 2.0 TFSI and a single S6 5.2 V10 FSI.

Interestingly, I also own a 2007 Touareg with the 3.6 FSI engine which has been trouble free and never needs oil top-ups between changes. Either it's gas recirculation system is doing a better job or the lower compression and engine design is keeping the dilution and volatility low enough that it's taking longer for the issues to appear. It's now at 31,000 kms.

Just got a call from the service advisor. They've completed all the intake port and valve cleaning, replaced the injectors, and have talked to Audi Technical one more time before putting it all back together. Audi has now asked them to replace the cyclonic oil separator with a new one which is now being rush shipped to my dealer. They've also decided to replace a vacuum line on the intake manifold that feeds the tumble flaps according to a TSB, which i recall a few other RS4 owners discussing. Apparently the factory line set-up can become easily kinked so they are replacing it as a preventative measure.

Wondering if this new oil separator could be an updated part. Anyone here know the part number and revision code of the OEM?

Thanks for the update.

How was it diagnosed or did it manifest itself. Mine is at 22K and I am wondering when this is going to hit (if it has)

How you guys are bringing it to an Audi dealer:
"my car is slow"
"my cel is on"

Help the noob

How was it diagnosed or did it manifest itself. Mine is at 22K and I am wondering when this is going to hit (if it has)

How you guys are bringing it to an Audi dealer:
"my car is slow"
"my cel is on"

Help the noob

It began idling very rough on cold starts, and would throw the MIL (engine) light. Dealer went went through all the known TSB's (coil-packs, vacuum lines) before finally taking it to Audi Technical (factory) for support.

How does the walnut shell cleaning work, first I have heard of this procedure.

How does the walnut shell cleaning work, first I have heard of this procedure. I recon other solvents wouuld work better than this, just wonder why Audi reverted to this method, they must have some proof it is the most optimal I imagine...

I recon other solvents wouuld work better than this, just wonder why Audi reverted to this method, they must have some proof it is the most optimal I imagine...

They use a combination of both.

They saturate the deposits with a solvent to soften them and then basically sand blast the valves and intake chamber - only they use ground walnut shells as blast media instead of sand. The walnut shells are great at scouring the deposits and absorbing access solvents, but cannot etch the metals. The added benefit is that any shell materials left in the chamber will be easily and harmlessly burned in combustion.

FYI - These deposits aren't flakey and soft as you'd expect. They're almost tar-like and very tenacious. If you look at the photos you can see where they had to take some scrapings from the valve stems to send to Audi for analysis.

Starting to sound a lot like the E39 M5 carbon problems, eh Tino? That was actually one of the reasons why I got rid of my '05... and now this.

How in the Sam he|| do you edit posts? What I meant to say is not '05 but '03 M5.

Is there any way to inject a cleaner like Seafoam injector cleaner above the valves in the intake somewhere and let it clean the valves?

As bstellar alluded to, the buildup is oily and tacky on the surface, sort of like half-cured epoxy. But once that is scraped off, the next layer is essentially cooked on. A solvent treatment with the manifold still on the engine will, at most, just wash all the tacky crud into the cylinders. The injectors will not like that at all. The best way to clean them is the process used by the dealer working on bstellar's car.

So whats the solution to the problem? Has Audi come up with anything?

Starting to sound a lot like the E39 M5 carbon problems, eh Tino? That was actually one of the reasons why I got rid of my '05... and now this.
Yikes!!! Yeah, mate, but even worse than in the E39 M5 case which was just a secondary air emmissions problem - in the case of the RS4 it affects performance as we have just seen, and it occurs a lot quicker in the vehicle's life, and seems to be more chronic and no fix (other than frequent walnut shell blasting!!!) has addressed it. With time (and as more FSI engines are rolled out), we will see this problem magnified!

Also, it seems to trip the CEL in many cases, so over time when cars are out of warranty - good luck trying to pass inspection without applying for a 2nd mortgage when you go visit the dealer to have it cleaned! That is unless someone like Powerchip (in our case - Revo perhaps) comes out with a flash that 'ignores' the fault code... But performance will suffer, so you pretty much HAVE to do it!

So my nightmares are anew... Gonna start lighting up candles each night, so far third set of DRCs are holding up, so there is someone up there that hears my prayers ;-o)

Wow, this is very crazy. Im looking into an RS4 for my next car, but this does scare me.. Has anything been acheived to slow, or reverse the problem other than the removal of the cylinder heads and walnut blasting?

The heads are not being removed. They do the work with the manifold off. Something to slow or reverse the problem? Not that I know of. I presume the buildup on any B7 RS4 is somewhere between moderate to sickening. The fine-oil separation system already on the car is either under-designed or not functioning properly. My guess is the former. The buildup leads to injector problems and misfires and I would think that it would eventually lead to catalyst problems.

I was thinking of getting another RS4 soon, since my 08 was totaled, but this makes me second guess myself, especially when the car runs out of warranty.

This is a big issue, and will become even bigger as time goes on IMO.

I think Im gonna have to get another M3.

The heads are not being removed. They do the work with the manifold off. Something to slow or reverse the problem? Not that I know of. I presume the buildup on any B7 RS4 is somewhere between moderate to sickening. The fine-oil separation system already on the car is either under-designed or not functioning properly. My guess is the former. The buildup leads to injector problems and misfires and I would think that it would eventually lead to catalyst problems.

If anyone missed my update, Audi has requested a sample of the deposits be sent in for analysis - so they're obviously taking this seriously as it's effecting all FSI engines not just the RS4. They've also sent out a new cyclonic oil separator to be installed and i'm trying to find a part number and revision to see if it's an updated part fro the OEM.

Several posts from Euro owners have mentioned this Wynns product but i have yet to find a retailer that stocks it. I'd be willing to give it a try if i could find it.

http://www.wynns.be/news.aspx?l=EN&isectionid=49&iarticleid=282

I was thinking of getting another RS4 soon, since my 08 was totaled, but this makes me second guess myself, especially when the car runs out of warranty.

This is a big issue, and will become even bigger as time goes on IMO.

I think Im gonna have to get another M3.

Yeah, but then you have people with 70,000 miles in 2 years on their RS4 with no problems whatsoever.

Yeah, but then you have people with 70,000 miles in 2 years on their RS4 with no problems whatsoever.

Not a risk Im willing to take at this time.
I had my RS4 for a short time, and it was in for unscheduled service far to often, especially when I compare it to my e46 M3, which was rock solid.
I'm looking to get a new car at the end of summer and will wait to see what Audi does to fix the problem, if they come up with something by then, then the RS4 will be high on my list again of cars to look at. If not, then I will move on...

But it will become a serious issue and expense when these cars start running out of warranty, the cost to to the owner to have this service done is going to be very high. Not something I would be looking forward too.

Has anyone discussed this problem with their service advisor even if you aren't throwing a check engine light?

Has anyone discussed this problem with their service advisor even if you aren't throwing a check engine light?

What about fuel selection? Is this happening with any brand of fuel?

This may sound silly, but is it something with the Ethanol possibly?

I know that Ethanol blended fuels have been horribly damaging marine fuel systems.

Has anyone discussed this problem with their service advisor even if you aren't throwing a check engine light? I did just this weekend as I went to pick up 3 bottles of the fuel additive AofA suggests. Costs $18 list, I picked up 3 as it has a long expiry date. Tech said he hasn't seen an RS4 just yet, but was fresh off cleaning a pretty gunked engine on a S6 (V10 FSI). Tech estimated at least a 4 hr job and suspected this will be needed service one vehicles accumulate miles and are out of warranty. There is a TSB (technical servce bulletin) on this topic.

I did just this weekend as I went to pick up 3 bottles of the fuel additive AofA suggests. Costs $18 list, I picked up 3 as it has a long expiry date. Tech said he hasn't seen an RS4 just yet, but was fresh off cleaning a pretty gunked engine on a S6 (V10 FSI). Tech estimated at least a 4 hr job and suspected this will be needed service one vehicles accumulate miles and are out of warranty. There is a TSB (technical servce bulletin) on this topic.

what fuel additive did they recommend?

what fuel additive did they recommend? I can't upload a pic as I guess it is over the forum limit. The bottle is a small 150ml thin container, serial/part number (G 001 700 03)

Must be very concentrated, states: "Mix 10ml for every 10ltrs of petrol"

Costs $18 list.

Ouch. As normal.... Audi tossed in a multiplier ..... found it for $7

http://genuineaudiparts.com/

Yeah, I am sure it is much cheaper there, but I know sometimes there are issues shipping 'flamables' via mail. Plus I wanted to put it right away. Thx for the heads-up!

same as this one I found on vortex I imagine:

http://i2.photobucket.com/albums/y38/eastcoastminiz/0813071025.jpg?t=1187016358

1 bottle ~ 40 gal of gas
that is pretty strong stuff...

1 oz / 8 gallons of gas

so what does this stuff do?

The walnut shells are great at scouring the deposits and absorbing access solvents, but cannot etch the metals. The added benefit is that any shell materials left in the chamber will be easily and harmlessly burned in combustion.

harmlessly burned in combustion? Walnut shells going through the motor? I'm gonna pass on that one.

If its the stuff they ran through my fuel system, its simply an aggressive fuel treatment to clean the injectors and combustion chamber. There is not much it can do for the valve buildup though. And any use of this I've seen to date is still followed by a manual valve cleaning by the dealer anyway. I don't believe its a cure or even a quick fix. Audi is simply following protocol. Step 1. change out plugs (zip) Step 2. swap a few coilpacks (nada) Step 3. Clean fuel system (zilch) Step 4. Test injectors for leakdown (getting closer) Step 5. Get out the solvent and walnut shells.

The level of buildup seen on bstellar's car and others can accumulate as quickly as 3000 miles. If people think they are somehow immune to the problem since they aren't having any CEL's, they are fooling themselves. The Pippyrips thread has photos of intake valves that look horrible, but he had no CEL's - his motor was actually running well except for the fact the the ECU was taking out lots of timing. My buildup levels were similar to bstellars and the symptoms were very similar when the dealer cleaned my valves. The car ran much better after that cleaning and no CEL's since. However, I've had the manifold off (3) times since and the buildup is still occurring. The only tell-tale is that the ECU is slowly taking out more and more timing (immediately after the cleaning it was taking out essentially zero) Unless Audi can magically reduce the oil volitization of the engine or greatly improve the fine-oil separation system already on the engine, this is not going away.

I wonder how similar this product is to the VAG cleaner.

This stuff is a gel like substance and you only use a little to treat your fuel system.

http://www.lucasoil.com/products/display_products.sd?iid=26&catid=8&loc=show&headTitle=%20-%20Lucas%20Fuel%20Treatment

harmlessly burned in combustion? Walnut shells going through the motor? I'm gonna pass on that one.


it's a standard method (sometimes peanut shells iirc) they use it on jet engines to clean the turbine blades...it's propbably the least destructive/harmful method

I wonder if this stuff would work:

http://www.tommymotorsport.com/liquimoly/engine_oil_flush.htm

If its the stuff they ran through my fuel system, its simply an aggressive fuel treatment to clean the injectors and combustion chamber. How much did you end up mixing with a full tank? It seems pretty concentrated (10ml for each 10ltr of gas). I think Bruised mentioned he had just added 20ml at first and even felt a performance difference, I guess this is also an octane booster? Was thinking of doing 1/2 a bottle as a first go, but may opt for only 1/3 if it is that concentrated...

What about fuel selection? Is this happening with any brand of fuel?

This may sound silly, but is it something with the Ethanol possibly?

I know that Ethanol blended fuels have been horribly damaging marine fuel systems.
I try to stick with Top Tier Gasolines as shown here: http://www.toptiergas.com/

What about fuel selection? Is this happening with any brand of fuel?

This may sound silly, but is it something with the Ethanol possibly?

Doesn't matter what fuel is used. The direct injection of FSI misses out on the natural cleaning effect that fuel has the intake valves seen in port injection, where the fuel spray is essentially pointed right at the valves. In other words, all the ads you see about how well a certain gas "cleans" valves, do NOT apply to a direct injected engine. They apply to the far more common port injected and carbureted engines. Nonetheless, Tier 1 fuels should be used for the RS4 due to its high performance nature and the fact that the cleaning agents do help maintain the fuel system.

Ethanol? Its a horrible substitute for petroleum, but using it or not using it doesn't have much affect on intake valve crud for the same reason as mentioned above.

How much did you end up mixing with a full tank?

The dealer did not say. Since they only put 25 miles on the car during the repair, I assumed they just flushed the fuel line and the injectors with the concentrate. Several injectors failed the following leakdown test just as they had prior to the flush. So, they replaced all the injectors, which I appreciated.

. If people think they are somehow immune to the problem since they aren't having any CEL's, they are fooling themselves. The Pippyrips thread has photos of intake valves that look horrible, but he had no CEL's - his motor was actually running well except for the fact the the ECU was taking out lots of timing. My buildup levels were similar to bstellars and the symptoms were very similar when the dealer cleaned my valves. The car ran much better after that cleaning and no CEL's since. However, I've had the manifold off (3) times since and the buildup is still occurring. The only tell-tale is that the ECU is slowly taking out more and more timing (immediately after the cleaning it was taking out essentially zero) Unless Audi can magically reduce the oil volitization of the engine or greatly improve the fine-oil separation system already on the engine, this is not going away.

I can't figure out why carbon buildup on the backside of the valves would effect ignition timing.

Because the same buildup that's on the valves is also in the combustion chamber. This is hardly speculation. The top of the piston and the spark plug are relatively clean due to the intense temps of the flame front. The bore is naturally clean due to the wiping of the rings. But the upper perimeter of the chamber can have the same epoxy-like buildup that is evident on the valves. It is this buildup, along with particles dislodging from the intake valves, that can damage the injectors. Just how the injectors are damaged, I don't know. In any case, they can no longer hold the residual pressure in the fuel system (or the test pressure when the dealer checks them). They slowly leak fuel into the cylinder. Upon start-up there is too much fuel in the cylinder and a misfire can occur. That is the advanced stages of the buildup are identified by a engine that runs very rough upon cold-start (it may or may not throw a code) and then runs better within a couple minutes. To answer your question, any source of carbon-based buildup in the combustion chamber of a 12:1 engine can definitely be a point of pre-ignition. Luckily, one of the 4 knock sensors detect it and pull out timing in the respective cylinder.

So at the end of the day, what is the solution to the problem????
The solution is not having to take if your intake manifold and have to clean it out IMO. Is Audi working on a solution even?

Carbon inside the combustion chamber can probably be dealt with using fuel additives, such as the Biosyn which I use regularly. Never used a fuel additive before, but I sure as heck am on this car. I thought the RS4 CR is 12.5:1?

I'm wondering whether (once cleaned) even simple water injection could keep the valves clean. It certainly would keep the chamber clean. That's been proven for years. However it would be a pain to have to keep filling a water tank.

Another thought I had is that a simple electrical vacuum pump could be used on the tube on the cyclone that normally goes to the inlet manifold. That pump could pump the oil into the crankcase instead of the intake. Keeps the system closed, but provides a better path for the oil.

Lots of cars have used such vacuum pumps for brake boosters and emissions, but I haven't seen one used in this manner.

Correction: vacuum pump on the return tube of the cyclone that goes to the crankcase.

There is an oil drain valve in that path that only opens at low rpm where the pressure from the valve covers and the bottom of the crankcase are about equal. A vacuum pump would force the oil collected by the cyclones into the crankcase all the time, not just at idle.

Carbon inside the combustion chamber can probably be dealt with using fuel additives, such as the Biosyn which I use regularly. Never used a fuel additive before, but I sure as heck am on this car. I thought the RS4 CR is 12.5:1?
Correct, CR is 12.5:1 (see pp.31)

http://www.jlosee.com/images/RS4/PDF/RS4_launch_doc.pdf

B-, def buy yourself one or two of the fuel additives, just keep in mind they are super concentrated.

I embrace the fact that people are thinking of ways around this, but the truth is it would not be 'rational' to mod your engine before the end of the warranty. Even if someone figures out a great solution (oil catch can or other) that is proven to work, I am sure AofA will void any warranty on the premise that the engine was 'tinkered' with. While I cringe at the thought of having to go get my manifold cleaned every oil change, at least it will be done with full warranty. Once out of warranty, that's a diff matter. I am (or should say - was) planning to keep this car for many years, but should I get a sense this is indeed spreading like the plague, I will have to dispose of it before warranty expires, unless AofA has an official recall and remedy... Speaking to my tech, he did acknowledge this is widespread across FSI engines, not just on RS4s.

In fact last week he had an R8 for the same issue. Coincidentally, that same R8 was burning 1 qt oil every 500 miles, which I recon is excessive. Wonder if there is a direct relationship - i.e. cars exhibiting excessive oil burn (be it because of bad break-in or other) are more prone to CB.

Wonder if there is a direct relationship - i.e. cars exhibiting excessive oil burn (be it because of bad break-in or other) are more prone to CB.

I bet you are right. That oil has to go somewhere, and it has to be out the tailpipe via the intake scavenging. Maybe the cyclones can't deal with the excess oil that badly sealed rings dump into the system ?

I have a 08 A6 with the same problem, dealer said Audi is working on a new ECU program that reatard the timing to fix this problem. SA also said this is a problem with new Audis during break in period and the problem will not re-occur. What do you guys think, will the problem re-occur?

I have a 08 A6 with the same problem, dealer said Audi is working on a new ECU program that reatard the timing to fix this problem. SA also said this is a problem with new Audis during break in period and the problem will not re-occur. What do you guys think, will the problem re-occur? My bet is that it will reappear if you had it once already and fairly early in the car's lifecycle.

As far as retarding the timing - not only will it not cure the problem, it will rob your car of HP. I can't imagine this being a viable solution. I think you spoke to a salesman/dealer, not a tech, the latter won't make statements like that...

My bet is that it will reappear if you had it once already and fairly early in the car's lifecycle.

As far as retarding the timing - not only will it not cure the problem, it will rob your car of HP. I can't imagine this being a viable solution. I think you spoke to a salesman/dealer, not a tech, the latter won't make statements like that...

Maybe he meant to say valve timing, not ignition timing. The RS4 does have variable valve timing so by changing overlap (both valves open at the same time) in the ECU, it might improve the carbon issue but perhaps at the expense of emissions. Just a hunch.

This thread is informative and concerning, just like the E39 M5 vanos conversations as well as the early-production E46 M3 sodium valve "issue"

One would think - at least I would - that if there's so much crap attached to the backs of the valves, the engine sound would be different. Possibly noisier if the valves aren't fully seating, right? I have 13,000 miles on mine with no check engine lights. I run 76 gas, 91 octane (the highest we get in CA) with two or three gallons of 104 racing fuel added first to get the average octane up around 93.

I don't notice any hesitation, and the car pulls just as strongly as it did after the first oil change at 3,000 miles.

The warning signs of an impending problem seem to be rough-starts, rough-running engines, reduced power, and check-engine lights.

I guess I'm wondering why some engines are more susceptible to the issue? I understand environmental variables like break-in, oil change frequency, fuel types, and driving style can contribute, but does that really affect the tolerances *so* much so that an engine with 3,000 miles on it can have symptoms that one with 60,000 miles doesn't? Do we know if there have been any changes to the injector design that would make some more prone to leak than others? Are they all sourced from the same supplier?

The perimeter of the valve that contacts the seat actually stays clean, but is only about .060 wide. Just inside of this clean perimeter is a "ridge" of buildup that represents probably the thickest layer of buildup anywhere on the valve (except on the valve stem, just below the portion of the stem thats wiped by the valve guide). This ridge must effect air flow into the chamber since the valve lift could not be more than .40-.50 inch.

To clarify what you're saying, rough running when cold, random misfires and CEL's is an early indication of possible injector leakage, not intake valve buildup. Occurrences of heavy buildup have been found in engines that had no real prior issues such as rough running, misfires and CELs. The injector issue may simply be a manufacturing problem. The valve buildup in my opinion could be found to some degree on every FSI engine on the road. It just so happens to amplify the problem presented by any FSI engine with faulty injectors. In other words, intake valve buildup and injector issues are related, but separate, problems. The engines being taken apart to replace injectors apparently unveil cruddy intake valves 100% of the time. Does that mean the buildup caused the faulty injectors or does it mean that the injectors were bad from the get go and the intake valve buildup is there regardless since its a FSI engine? I think its the latter. I've have my manifold off (4) times. The first time is when the all (8) injectors were replaced. I've had no CEL's, misfires, or rough starts since. However, even with various brands of oil, warm-up procedures, aggressive fuel system cleaners and various Tier 1 fuels, some level of intake valve buildup has been present during the (3) following times the manifold was off. So even though my RS4 actually starts and runs "fine", I know for a fact that there is buildup on the valves.

but do cruddy intake valves alone affect performance?

My bet is that it will reappear if you had it once already and fairly early in the car's lifecycle.

As far as retarding the timing - not only will it not cure the problem, it will rob your car of HP. I can't imagine this being a viable solution. I think you spoke to a salesman/dealer, not a tech, the latter won't make statements like that...

I actually talk to my SA and he ask the shop foreman to come out and answer my questions as well. All he said was the new ECU program, which will be out in 2 to 3 months, will change the timing, he didnt say what kind of timing and I didnt think to ask. Anyway, got the car back today, they found minor built up in 2 areas and clean it with a solvent, pour in some injector cleaner, pressure tested the injectors and vaccum tested the cylinders. Let the car sit over night and had minimal misfiring in the morning. According to my SA, all Audi have some misfiring when cold, and the amount on my car was acceptable. I will updated you guys if the CEL comes back.

I actually talk to my SA and he ask the shop foreman to come out and answer my questions as well. All he said was the new ECU program, which will be out in 2 to 3 months, will change the timing, he didnt say what kind of timing and I didnt think to ask.

When I went for my 5k service, they updated the software of my ECM. That update was supposed to help cold starts. Is the ECM the same thing as the ECU?

I think ECM is the same as ECU, maybe they have a TSB for the RS4 already, I do not know. I have a A6, I am just here because I have the same problem.

SilverRS4: Thank you for that clarification, it makes perfect sense.

I wonder how much each valve weighs, and how much weight is added by the crud on the backs of them. Do you think the physical weight of the deposits is impeding the valve's ability to perform its task? (other than closing and seating properly)

Also, with the manifold off, are each cylinders' intake valves covered equally by the same amount of crud? Or is it more localized front-back or from one bank to another?

-Matt

I think the problem with carbon deposits on the intake valve is all about flow characteristics.

SilverRS4:
I wonder how much each valve weighs, and how much weight is added by the crud on the backs of them. Do you think the physical weight of the deposits is impeding the valve's ability to perform its task? (other than closing and seating properly.

Also, with the manifold off, are each cylinders' intake valves covered equally by the same amount of crud? Or is it more localized front-back or from one bank to another?

The restricted flow into the cylinder would be the primary concern. The ridge of buildup on the valve perimeter and the "lump" on the stem are in the worst possible places. I don't think the weight is really an issue. Just how much the airflow and engine performance is hurt is really hard to say.

The distribution of buildup from cylinder to cylinder is fairly even, but if I had to pick based on what I've seen, the rear (2) cylinders on each bank tend to be the worst. These are the two that are closest to the where the cyclone separator is venting the crankcase air into the manifold.

SilverRS4-

Have you been using Scott's recommendation of RLI 5w-40?
If yes, have you removed the manifold to inspect how the oil performed and what did you find? I also wanted to ask how the new nitrogen enriched gas from shell v-power would help this problem if at all.
TIA.

I'm wondering whether (once cleaned) even simple water injection could keep the valves clean. It certainly would keep the chamber clean. That's been proven for years. However it would be a pain to have to keep filling a water tank.

Another thought I had is that a simple electrical vacuum pump could be used on the tube on the cyclone that normally goes to the inlet manifold. That pump could pump the oil into the crankcase instead of the intake. Keeps the system closed, but provides a better path for the oil.

Lots of cars have used such vacuum pumps for brake boosters and emissions, but I haven't seen one used in this manner.

adding a water/meth kit prior to the throttle body should keep things clean

capture/reuse the water from the combustion process, there are many gals produced
inject it into the intake
repeat until clean
:D

how much water is produced per gal of fuel burned

RS4Power -
I’ll try to get the whole history as brief as possible. It’s lengthy, but hopefully informative. From the time the car was broken in, the cold starts were frequently rough and power delivery was erratic. The roughness should not be confused with a hunting or oscillating idle. It was caused by misfiring, as verified with Vagcom. It eventually got to the point when there would be 30-40 random misfires in the first 15 seconds. First oil change was at 4k by the dealer. By 8k miles, I had been in twice for “coil” issues to “correct” the CEL’s caused by the misfires. The coils were not the problem. The Service Mgr (not the SA, who was clueless) decided the fuel system should be checked. Four injectors failed the leak-down testing. Upon removing the intake to replace all 8 injectors at 8k miles, they discovered a disturbing amount of buildup on the intake valves. I saw the buildup, but did not take any photos. The dealer did a very good job of cleaning them and with the new injectors, the car ran much, much better. There have been no misfire issues since. I have hooked up Vagcom several times after the car has been sitting for 2-3 days and zero misfires are recorded – the engine fires up nicely, just as it should. The dealer used a fair amount of solvent when they cleaned the valves, so I changed oil at 8k, using the Castrol TXT synthetic available from the dealer. At 9k miles, I swapped in my ported intake. Low and behold, after only 1000 miles on a good 501/502 oil, the intake valve buildup was already at least 1/2 of what it was at 8k. I had figured that with good injectors that were no longer leaking fuel into the cylinders when the engine was off, there would less fuel dilution of the oil, less oil vapor in the crankcase air stream and much less buildup. Apparently not. So I cleaned the valves (major PITA), and decided to start using the RLI 5W-30 oil and fuel conditioner. At this point the car was running very strong. At 11.5k miles, I swapped in my version 2 ported manifold. After 2500 miles on the RLI oil, there was some buildup on the valves, but it was minimal. 500 miles later, I swapped manifolds again and of course the valve condition hadn’t changed much. The buildup rate is definitely slower with the RLI oil. So what have I learned? 1) The high performance nature of the RS4 engine means it volatizes a lot of oil, plain and simple 2) Generally speaking with FSI engines, rough cold starts and misfires are probably injector related – a bad coil would misfire all the time and minor valve buildup apparently doesn’t cause misfires 3) The injector problems are isolated and may be due to a manufacturing tolerance issue 4) I’ve used Tier 1 Shell fuel exclusively, it may keep the fuel system clean, but it does absolutely nothing for intake valve deposits on a FSI engine 4) A good fuel conditioner will help with maintaining clean injectors and minimizing combustion chamber deposits, but with a FSI engine, its affect on the intake valves is minimal 5) Oil chemistry can make a difference with the rate of buildup 6) Even considering the oil volatization of the RS4, there seems to be an abnormal amount of oil in the intake, as if the fine oil separator system is overwhelmed or does not work at all. There is a drain line that lets the separated oil drain back to the oil pan. But it has a simple valve so that it drains only when the pressure on both sides of the valve equalizes. This equalization really only happens when the engine is turned off. One possible scenario here; if the valve doesn’t work, all the oil gets sucked back into the manifold and the separator is doing effectively nothing. This oil vapor is what’s cooking on the valves. With a 3-stage cyclonic separator, you would think that if the system worked, there really would not be such a big problem with oil vapor in the intake. That may be why the separator was changed out on bstellar’s engine. However, the swap looks more like a guess rather than an update. Considering the impact of an updated separator that was intended to correct the build-up problem on a FSI engine, you’d think there would be a recall or at least a TSB. That does not seem to be the case.

Nice write up SilverRS4, it seem like this carbon built up issue is starting to spread to other other models as well. Did Audi change something with their valve timing in the 07 to 09 FSI engines? It seems like only the newer Audi have this problem.

Great post silver.. I/we appreciate the time you've taken to document your experience, which seems more of an inevitability for the rest of us the more I read about it.

I was wondering if the Q7's 4.2 FSI motor is exhibiting similar symptoms due to the similar design of the engine, but upon further investigation it looks as though the two engines differ in the way the oil settles back into the crankcase. I asked my dealer if they had any 4.2 FSIs in for carbon/oil/valve issues and he said only for the RS4 and R8 so far. There are probably 5x the number of Q7s 4.2s in service compared to the RS4/R8s, so I wonder if the problem is limited to ours, or just not realized by the Q7 owners for one reason or another.

-Matt

I'm particularly curious (per the second attached doc above) about the following:

1 - 'piston ring flutter at high engine speeds and low engine loads can result in a very high gas-flow rate.' what does that mean...revving the engine at a standstill?

2 - 'when the bypass valve opens, a fraction of the blow-by flows to the engine untreated, but the remainder is treated optimally by the cyclones.' is this 'fraction' the stuff that's settling on the valves?

Great post silver.. I/we appreciate the time you've taken to document your experience, which seems more of an inevitability for the rest of us the more I read about it.

I was wondering if the Q7's 4.2 FSI motor is exhibiting similar symptoms due to the similar design of the engine, but upon further investigation it looks as though the two engines differ in the way the oil settles back into the crankcase. I asked my dealer if they had any 4.2 FSIs in for carbon/oil/valve issues and he said only for the RS4 and R8 so far. There are probably 5x the number of Q7s 4.2s in service compared to the RS4/R8s, so I wonder if the problem is limited to ours, or just not realized by the Q7 owners for one reason or another.

-Matt

It's not just the high-revving 4.2 in the RS4 and R8. There have been numerous posts on forums regarding the 2.0 TFSI having deposit build-ups on the intake valves. My service advisor has also had 2 5.2 V10s from an S6 and S8 that have needed walnut blasting to remove intake valve deposits.

The high-output nature of these engines and their gas recycling systems might be an exasperating factor. As i've posted earlier, i also own a 2007 Touareg with the newer 3.6 FSI engine that has been strong and trouble free for over 32,000 kms to date. I'd love to see what the intake valves on it look like.

My dealer told me that they did 2 carbon cleaning thos month on 2 08 A6 3.2L, so its not just the high output engines that have this problem. The tech pointed out that this is a problem on the A6 during the break in period. Reading the doc above, I wonder if the oil cyclone system having a problem with the break in oil Audi uses. Generally, break in oil is thinner and lighter, in theory, a cyclone seperator should be less effective with a lighter oil weight.

What do you guys think of that theory?

Silver, are you using RLI 5W30, or 5W40? I'm hoping that 5W30 is a typo.

Greatwhite –

The Q7 and RS4 have the same separator, drain-line, and drain entry point (the innerV cover). Its my understanding that the only difference is in the breather piping, which really doesn’t effect the separator’s performance. The Q7 engine probably isn’t such a oil volatizer as the RS4, but probably has similar issues. My dealer had to do similar repair work on at least one Q7 4.2FSI.

Piston ring flutter most commonly occurs after the engine has been accelerated under load to a high RPM and then the load is removed (i.e., you ease up on the accelerator pedal). The flutter occurs as the engine decelerates. Revving the engine to very high RPMs with no load would also do this. I believe the high-RPM, low-load “flutter” is due to reduced cylinder pressure. It’s this cylinder pressure that necessary to keep the pistons and rings perfectly square to bore (hence providing a good seal) and this pressure is a function of load.

I don’t think the culprit is some fraction of the blow-by gas volume. I do think it may be possible that there is a much larger portion of blow-by gas volume that’s not being treated at all, or the separated oil fails to drain properly and is vented into the manifold because it has nowhere else to go.

Mr G – I don’t think the viscosity of the oil has anything to do with the separator’s ability to remove the oil vapor from the blow-by gas stream. The buildup is occurring on most if not all FSI engines well after the break-in period has passed. A poor break-in may make the problem worse, but the viscosity of the oil probably isn’t the issue.

RI A6 - Sorry, it was a typo. I've given up editing my posts.

Silver, thanks for the clarification on the RLI 5W40 oil.

You should see much lower deposit formation rate. The RLI oil should reduce the amount of fuel ingress, volatilize less, and provide in-situ cleaning. You won't keep oil off the intake valves, but you should greatly reduce the bad stuff that happens when it does get on there. It will also continue to work better after the next two oil changes, as it cleans out the residue of the previous factory oil and Castrol chemistry.

this all is. Leave installed for a set period of time and see how much oil is collected in the catch can passed the cyclonic system Audi has in place. If it's quite a bit then there is a call to have a catch can, add in an oil return like Audi to the block or pan, and it should be fairly maintenance free. If build up is still an issue a breather system that is free to air and doesn't return to the intake path at all could be installed, however that is not legal in most cases and if the RS4 has a leak detection pump it will throw a code.

Cheers,

I'm particularly curious (per the second attached doc above) about the following:

1 - 'piston ring flutter at high engine speeds and low engine loads can result in a very high gas-flow rate.' what does that mean...revving the engine at a standstill?

2 - 'when the bypass valve opens, a fraction of the blow-by flows to the engine untreated, but the remainder is treated optimally by the cyclones.' is this 'fraction' the stuff that's settling on the valves?


1 exactly, or accelerating up to redline very slowly
2 probably

it's hard to say how efficient the cyclone(s) are, they typically are only efficient over a very narrow range, hence the complicated control syste, 3 cyclones, sequencing valve and by-pass valve

rev'ing an unloaded engine is not good, it's making power, but is not delivered, so it 'bounces' around in the engine...rods, crank, etc.
for every action = opposite = reaction...it's usually the road or accelerating/moving a mass..if the car is stationary and not in gear, it's the engine that must provide the countering forces

I'ld be curious how much power is made in this scenario...

BMW recommends against it in writing...

According to the VW Vortex owner, there was 8 oz of fluid after 1200 miles.

http://i140.photobucket.com/albums/r34/saaber1/1100miles8oz.jpg

In a Terry Dyson oil analysis, he screens for soot, fuel dilution, oxidation, nitration, and TAN (acidity). These are used as indicators of deposit formation. This is how he was able to predict this problem with the engine two years ago, and guide us towards a different oil chemistry.

According to the VW Vortex owner, there was 8 oz of fluid after 1200 miles.

http://i140.photobucket.com/albums/r34/saaber1/1100miles8oz.jpg

looks like an oil/water emulsion...

was the catch can before the factory seperator?
or after?

in my experience. In nearly 6 months of driving, forgot to drain the can, I found half that in probably 10-15k miles of use. This was an open to atmosphere setup on an '01 S4 running fairly low boost, nonetheless still running boost. My other cars have been on par with my S4 as well, could really ignore the catch can for 4-5 months before it needed to be emptied.

I do wonder if that was pre or post the cyclonic system. I'd be curious to see after Audi's system to see how much is actually getting through.

If I owned an RS4 I'd have a catch can in immediately, for that matter any FSI equipped car I planned on keeping out of warranty.

Cheers,

In a Terry Dyson oil analysis, he screens for soot, fuel dilution, oxidation, nitration, and TAN (acidity). These are used as indicators of deposit formation. This is how he was able to predict this problem with the engine two years ago, and guide us towards a different oil chemistry.
I've used Terry before on my M5, the best guy in the business. In fact, I have bought a kit and waiting for my next oil change to send him a sample. Will have to wait in breathless anticipation for the results...

though you probably know that from the sounds of it. The foul liquid that comes out of the catch can in my S4 looks similar, usually a bit darker, but nowhere near that much in 1200 miles. However that lack of darkness could mean the oil was fresh when he installed the catch can or it's more water than anything else. If it's passed the cyclonic system it would show that mostly water vapor is being brought back in which could be beneficial, but from what we've seen in pictures of intake valves it doesn't seem like it's water vapor going back in, it's nasty nasty.

Cheers,

though you probably know that from the sounds of it. The foul liquid that comes out of the catch can in my S4 looks similar, usually a bit darker, but nowhere near that much in 1200 miles. However that lack of darkness could mean the oil was fresh when he installed the catch can or it's more water than anything else. If it's passed the cyclonic system it would show that mostly water vapor is being brought back in which could be beneficial, but from what we've seen in pictures of intake valves it doesn't seem like it's water vapor going back in, it's nasty nasty.

Cheers,

it does look like mostly water (the oil has risen to the top), I bet <20% oil, if that...
so a couple of oz. in 1200 miles (1 qt per 24000 miles), not bad...

whether it's before or after is the $64,000 question ;)

but either way, not so bad...
I think 3 things exasperate the issue in the RS4:
-no fuel to wash the valves
-with the wide engine rpm band the cyclones have a wide range of low efficiency
-the valves are hot, what does get thru gets cooked onto them

I think a catch can would help immensely, baffled or with a cyclone, small capacity to allow the hot water vapor (steam) pass without condensing...better yet, heat it with engine cooling water...the oil would condense, much higher vapor point...

to get much of this vapor out before that air is back into the intake system. Would it be better to just plumb it right to a vented catch can and keep any of the crank vent back into the intake. I bet adding an additional catch can, like a vortex type can, inline after Audi's system would likely do a lot, but not solve the issue entirely.

Cheers,

I'm done wrenching on the car. How about I give Audi $70k and they give us all a catch can that works. Oops, I forgot. I've already already done that.

We still need to figure out which brand of catch can will work with the RS4 and we need to get all the associated hardware. Also, where is there friggin' space to put it?

How about a intake water/meth injection. Doesn't water/meth vapor have the side effect of washing down the valves and cylinders? I am not sure it would dissolve the existing stuff but wouldn't it prevent/wash anything coming in?
Side effect depending on the mix you can feel like you are running race gas, less possible detonation less chance of the ECU pulling timing. With a car running over 12:1 compression it can't hurt and it would probably help. Drawback is since it is like adding fuel (if you add methanol) you may need to remap the ECU to handle it.


Cheers

Nick

just have to find a shape that fits and get some plumbing figured out. There is a round Vortex separator which, if there is room, could be firewall mounted inline. There's always room around somewhere, just the trick of keeping it clean and OE looking. I run an open can which is held in place in an OE bracket with an plastic cover over it. You cannot tell it even exists.

If anyone is interested could possibly work on getting some parts together to make a kit, just need someone willing to work on fitment with making it OE in appearance and fitment. Personally I'd do a system right after the cyclonic system Audi has there, just place it inline. It's not a high pressure or vac system so if that is hard plastic hose running from that separator just cut a portion out, use rubber hose to route to a can, then route from can back to factory plumbing. Can, rubber hose, clamps, maybe a bracket.

Anyone have pictures of the engine bay without the top carbon cover on? Also pics of that separator and plumbing?

Cheers,

I'd like to se a small experiment...

just put a paper fuel or charcoal canister filter inline and see what gets collected...

How about something like this Steeda Oil Separator

Link below
http://www.steeda.com/products/steeda_oil_separator.php

How about something like this Steeda Oil Separator

Link below
http://www.steeda.com/products/steeda_oil_separator.php

maybe...

the difficult part is where to mount it
both physically and location in the process, before or after the cyclone unit...

that might be easy to do, mount 2, one in each valve cover hose...

How about something like this Steeda Oil Separator

Link below
http://www.steeda.com/products/steeda_oil_separator.php


Ha, that's a joke. You ca buy that oil separator at Home Depot for like $5.00. It's from Husky and it's carried at Home Depot.

Better yet, go to Sears and get theirs for $24.00. It's a bit larger and easier to drain.

Doesn't matter what fuel is used. The direct injection of FSI misses out on the natural cleaning effect that fuel has the intake valves seen in port injection, where the fuel spray is essentially pointed right at the valves. In other words, all the ads you see about how well a certain gas "cleans" valves, do NOT apply to a direct injected engine. They apply to the far more common port injected and carbureted engines. Nonetheless, Tier 1 fuels should be used for the RS4 due to its high performance nature and the fact that the cleaning agents do help maintain the fuel system.

Ethanol? Its a horrible substitute for petroleum, but using it or not using it doesn't have much affect on intake valve crud for the same reason as mentioned above.

I think you may be mistaken. These new gasolines are formulated for direct injection engines. There are two that I know of, which are the only 2 that you should be putting in your RS4's. They are Chevron and the new Shell with Nitrogen, both of which help with the carbon buildup. The detergents in these gasolines are vented via the PCV and do in fact hit the back of hte valves when they reenter the motor. Granted they are mixed with oil, but they are supposed to help.

I don't know what the back of my valves look like but have never put anything else but Chevron n my tank. I also use Motul oils and switch it out every 2,500 miles and i use that intake deposit cleaner from Audi which actually feels like it does something.

The detergents in these gasolines are vented via the PCV and do in fact hit the back of the valves when they reenter the motor.

Well, in that case there will be copius amounts of detergent hitting the backside of RS4 intake valves. Are there any scrubbing bubbles along with the nitrogen? I see and agree with your point - fuel chemistry, oil chemistry, and additives all have their purpose; but by themselves they will not fix this. Practically everyone posting on this forum is particular about oil performance, oil change intervals and fuel quality. The sure benefit of such diligence is stellar looking journal bearings, wear surfaces, and fuel system components. It does not mean clean intake valves on an RS4 engine.

I think you may be mistaken. These new gasolines are formulated for direct injection engines. There are two that I know of, which are the only 2 that you should be putting in your RS4's. They are Chevron and the new Shell with Nitrogen, both of which help with the carbon buildup. The detergents in these gasolines are vented via the PCV and do in fact hit the back of hte valves when they reenter the motor. Granted they are mixed with oil, but they are supposed to help.

I don't know what the back of my valves look like but have never put anything else but Chevron n my tank. I also use Motul oils and switch it out every 2,500 miles and i use that intake deposit cleaner from Audi which actually feels like it does something.

I hadn't considered the recirc gas doing the cleaning,,,interesting, good info, thnx
all I use is Shell 93

if the oil is hot enough it can act as a cleaning agent itself...
my dad was a machinist and oil was always used to clean metal...

How about a intake water/meth injection. Doesn't water/meth vapor have the side effect of washing down the valves and cylinders? I am not sure it would dissolve the existing stuff but wouldn't it prevent/wash anything coming in?
Side effect depending on the mix you can feel like you are running race gas, less possible detonation less chance of the ECU pulling timing. With a car running over 12:1 compression it can't hurt and it would probably help. Drawback is since it is like adding fuel (if you add methanol) you may need to remap the ECU to handle it.
Nick

I always thought this would be a good idea to over come problems with supercharging the RS4, but I agree that it would help in cleaning the carbon deposits. It has been well documented in other engines.

Well, in that case there will be copius amounts of detergent hitting the backside of RS4 intake valves. Are there any scrubbing bubbles along with the nitrogen? I see and agree with your point - fuel chemistry, oil chemistry, and additives all have their purpose; but by themselves they will not fix this. Practically everyone posting on this forum is particular about oil performance, oil change intervals and fuel quality. The sure benefit of such diligence is stellar looking journal bearings, wear surfaces, and fuel system components. It does not mean clean intake valves on an RS4 engine.

Silver, you are not totally correct. There are several totally related problems.

1) High fuel dilution in this engine causes rapid oil breakdown of volatile components, increasing the volume of gas recycled by the PVC system. Those volatile components of the fuel and oil tend to be highly active and form deposits easily.

2) High fuel dilution decreases oil viscosity, decreasing ring seal, thereby causing increasing levels of fuel dilution.

3) High fuel dilution with ethanol enriched fuels, causes increased levels of water and alcohol in the oil, again increasing the level of gas recycled by the PVC system, and leaving behind a gradually increasing volume of ethanol and water, also depressing viscosity.

4) Intake valve temperatures are at nearly the perfect temperature to facilitate deposit formation, as they run hotter in GDI than PFI engines, but lower temperature than exhaust valves. It turns out that the intake valve temperature of GDI engines is at the sweet spot for deposit formation.

Thus there is a synergistic loop that is formed between the original problem, fuel dilution, and the final problem, intake valve deposits. Rate of formation can be decreased with a multi-fold strategy.

First, the oil must have extremely good high temperature properties, low oxidation and low deposit formation. This is achieved with RLI Biosyn formulations, which have one of the lowest deposit formation rates in the industry.

Second, since deposits will form, the oil must have the ability to clean at high temperatures. This is accomplished in Biosyn with Bio-esters which, along with excellent lubrication and high temperature properties, have exceptional cleaning abilities.

Third, the oil must have the ability to contain and make inert fuels, alcohols and waters that enter the oil. Biosyn esters are polar, and as such have the ability to attach to the polar water and alcohol molecules, rendering them less active.

Fourth, the oil must maintain good high temperature viscosity under the chemical attack of aromatic hydrocarbons from the fuel, in the rings and cylinders. This is accomplished by the design of the oil ... AND ... by the design of the fuel and fuel additives. The amine-chemistry in Shell V-Power has been specifically designed for direct injection engines to increase lubricity, neutralize aromatic hydrocarbon byproducts that enter the oil, and to continue to provide cleaning when recycled through the PVC system. This is not marketing hype. Shell created the new formulations in direct response to issues with direct injection engines in the field.

Fuel chemistry alone cannot do everything. That is why those customers of Terry Dyson, who have had oil analysis, receive a fuel additive formula, known as DSFM, that can be added to each tank of fuel, and is designed to work with the VPower and the RLI Biosyn chemistry, to keep the cylinder/ring seal tight, reduce fuel wash down, counteract the bad effects of aromatic hydrocarbons in the oil, and provide additional secondary cleaning through the PVC system.

I think you may be mistaken. These new gasolines are formulated for direct injection engines. There are two that I know of, which are the only 2 that you should be putting in your RS4's. They are Chevron and the new Shell with Nitrogen, both of which help with the carbon buildup. The detergents in these gasolines are vented via the PCV and do in fact hit the back of hte valves when they reenter the motor. Granted they are mixed with oil, but they are supposed to help.

I don't know what the back of my valves look like but have never put anything else but Chevron n my tank. I also use Motul oils and switch it out every 2,500 miles and i use that intake deposit cleaner from Audi which actually feels like it does something.

Here is a post I found in another forum, looks like the new nitrogen gas is the same old gas they been selling for years, just another marketing scheme.

I asked Edmunds.com Engineering Editor Jason Kavanagh what, if anything, was special about Shell’s new gasoline. He said he believed that nitrogen was used in most detergent gasolines. After learning that, I went to Chevron’s web site to see if their gasoline was also nitrogen-enriched. Sure enough, it is.

Here’s their spiel:

http://www.chevron.com/products/ourfuels/chevwtech/

Chevron gasolines with their nitrogen-enriched Techron additive contain polyether amine (PEA) chemistry to help keep vital engine parts cleaner than lower quality competitors, helping reduce the amount of hydrocarbons, carbon monoxide and nitrogen oxides released into the atmosphere. It all adds up to a cleaner and happier car.

The new Shell Detergents are based on an amine chemistry. Terry Dyson has done work for Shell and knows the chemists involved. He assures me that at the time that they began advertising Nitrogen (amine) additives, an entirely new formulation was introduced in the US that was specifically enhanced for direct injected engines.

The new Shell Detergents are based on an amine chemistry. Terry Dyson has done work for Shell and knows the chemists involved. He assures me that at the time that they began advertising Nitrogen (amine) additives, an entirely new formulation was introduced in the US that was specifically enhanced for direct injected engines.


this is good to know...

I've use nothing but Shell 93, I wonder what my valaves look like?

;)

this is good to know...

I've use nothing but Shell 93, I wonder what my valaves look like?

+1 here. Always use the Shell 93 V-Power. BTW, the name (V-Power), is that just marketting mumbo jumbo so we all think we are Kimi Räikkönen? LOL

+1 here. Always use the Shell 93 V-Power. BTW, the name (V-Power), is that just marketting mumbo jumbo so we all think we are Kimi Räikkönen? LOL

You guys are lucky. We only get 91 in CA. Well, until I found this little gem (@Pico and Barrington in WestLA) A few gallons of this stuff should keep the tank at 93-94. Pretty soon they're gonna need another digit on that meter. :)

+1 here. Always use the Shell 93 V-Power. BTW, the name (V-Power), is that just marketting mumbo jumbo so we all think we are Kimi Räikkönen? LOL


may be? ;)

http://www.youtube.com/watch?v=Gh_U7Ul2v0A

Exactly, Shell's gas now has the stuff that Chevron's has had it t for years. It's great stuff and does in fact work for DI engines. So now, the only two gasolines on my list are Chevron and Shell, bot of which are good for di engines.

hello: my rs4 had the same problem after i brung the car to the dealer they kept the car for a month and they replaced the injectors and coils and flused the gas tank amd they gave me $24.000 for the inconvinece the car is fine now.

sorry i missed typed 2,400.00

sorry i missed typed 2,400.00

No way......

maybe...

the difficult part is where to mount it
both physically and location in the process, before or after the cyclone unit...

that might be easy to do, mount 2, one in each valve cover hose...


I think 2 clear high temperature corrugated hoses (e.g. http://www.mcmaster.com/#tubing/=1p7kxz) running from the valve covers down to an oil separator located near the oil filter, then a hose coming back up to the cyclone oil separator. Then you have gravity working for you. Any oil that condenses on the tube goes down to the separator, the long tubes allows cooling off of the gas to promote condensation/separation, plus being clear, you can see what is happening. These high quality tubes aren't cheap, but neither is removing the manifold and cleaning the valves.

I have a 08 A6 3.2 with the same exact problem. 12 days at the dealership and still havent gotten the car back. That cleaner crap didnt work. I hope to hear others have the same issue with non- RS4 models.

Just had my car serviced, Not sure if I wasted my money but I had them do some Fuel system cleaner. $110 for the labor and $42 for the induction kit. Only use Shell 93 Vpower and haven't noticed any problems but figure this is fairly cheap preventive maintenance

I found this while digging through the bowels of the site.

http://blogs.edmunds.com/greencaradvisor/2009/03/direct-injected-gas-engines-more-susceptible-to-efficiency-robbing-carbon-buildup.html

I found this while digging through the bowels of the site.

http://blogs.edmunds.com/greencaradvisor/2009/03/direct-injected-gas-engines-more-susceptible-to-efficiency-robbing-carbon-buildup.html


thnx, nice find & very interesting...

looks like they are aware of the problem, and are seeking to remediate...

This has been a know issue in out Mazdaspeed6's for a while. We had to install an OCC and delete the EGR. These are things that you should look into doing as soon as you have the dealer clean it for you. It is a must on our cars and Im sure yours too. The oil seperator im sure will not work well enough and looking at those pictures I gaurentee you all have an EGR as well. I can help provide more info but im sure it is limated with the fact that I know nothing about your engines. This topic was just linked to on my forums and I am already a memeber here so I figued I would post. Not knowing the rules I do not want to post any links yet thou even thou I did before for the LI GB I held.

There are no EGR components per se, I believe the same result is achieved through valve overlap control (passive). The build up has nothing to do with exhaust gases and everything to do with the high amount of oil vapor in the air charge. The oil separator system already in the car is either completely overwhelmed or not functioning properly. It is as simple as that.

There are no EGR components per se, I believe the same result is achieved through valve overlap control (passive). The build up has nothing to do with exhaust gases and everything to do with the high amount of oil vapor in the air charge. The oil separator system already in the car is either completely overwhelmed or not functioning properly. It is as simple as that.

SilverRs4-

Have you removed your intake manifold recently? How have you been liking Scott's recommended oil, Biosyn?
I have received the kit to send Terry Dyson a sample of my oil and switch over to the recommended oil. I want to get the valves cleaned before switching over though. What worries me is that my dealer has limited experience in this matter as they just did an rs4 and couldn't get all the CB off with the solvents recommended to them.

I talked to a gentleman that works for Audi Technical, (not sure what that means exactly) he told me to apply the BGK treatment and that walnut shell blasting was becoming the "unofficial" way Audi was attacking this matter. My dealer never heard of that approach so I forwarded this post to them. I shall wait for them to review and get back to me. What method did you apply when you cleaned the valves? I know you said it was a PITA. I am just hoping this becomes a one time issue after the clean up and oil switch.

Your thoughts please...

SilverRs4-

Have you removed your intake manifold recently? How have you been liking Scott's recommended oil, Biosyn?
I have received the kit to send Terry Dyson a sample of my oil and switch over to the recommended oil. I want to get the valves cleaned before switching over though. What worries me is that my dealer has limited experience in this matter as they just did an rs4 and couldn't get all the CB off with the solvents recommended to them.

I talked to a gentleman that works for Audi Technical, (not sure what that means exactly) he told me to apply the BGK treatment and that walnut shell blasting was becoming the "unofficial" way Audi was attacking this matter. My dealer never heard of that approach so I forwarded this post to them. I shall wait for them to review and get back to me. What method did you apply when you cleaned the valves? I know you said it was a PITA. I am just hoping this becomes a one time issue after the clean up and oil switch.

Your thoughts please...

I had the manifold off the fourth time about a month ago when there was close to 3000 miles on the Biosyn. The valves were not clean, but it was more of a thin, oxidized film of oil, rather than thick, gooey, flow-blocking black crud (which was the case after 4000 miles of factory oil, 4000 miles of Mobil 1, and less than 1000 miles of Castrol TXT). I was pleased and will certainly keep using the Biosyn. I am sure Scott could fill you in on the chemistry that makes the build up rate noticably less. I also use the Biosyn fuel conditioner (2 oz) with each fuel fill of Shell gasoline to make sure the injectors stay clean. With the FSI aspect of the 4.2L engine, I believe that sparkly clean valves is just not a realistic expectation - even with Biosyn. But I am happy with how its working thus far. The aspect that really hasn't been discussed is the affect that the oil "contaminated" intake charge has on optimum spark timing. The advanced RS4 ECM's and knock sensors seem particularly sensitive. After endless logging, I have a few cylinders that have timing retarded 4-6 degrees under moderate loads and 9-11 degrees under heavy loads. That is significant. I live in the Midwest and am stuck with Ethanol blended fuel even in the 91-92 octane Tier 1 fuels (Shell included)- that could be part of it, I don't know.

As far as my cleaning method, it was just the old fashion way. In six of the eight cylinders, the intake valves were completely closed, so I just poured in several ounces of carb cleaner right into the intake ports and let the valves soak several hours. Then a majority of the crud comes off with aggressive scraping with an appropriately shaped metal tool. The valve stems block the ability to scrape the area behind them. Vacuum out the mess. Then I poured in fresh solvent and put a small Dremel-type wire brush tool on the end of a cordless drill. Scrub, scrub, scrub. The varnish layer of buildup on the valve surface is very, very hard. This method is limited and removes 90% of the build up at best. The walnut shell blasting would be far better. I have access to such blasting equipment and media, but its ridiculous that I or anyone else has to consider such a chore ...warranty work or not.

Okay - today I will be dropping the factory initial fill (brand unknown) on my 2008 with 750 miles and switching to RLI's 5w-40 .... thought that I try it from the beginning. Any downside?

Earliest switch I've seen was at 2K miles. That owner is in Texas and now has around 25K on the engine with consistently good results in oil analysis.

Oil and filter change done at 750 miles. Let me know if you would like for me to contribute oil samples as I progress. What OCI should I follow on my RS4 with RLI? Would every 5K suffice? I am also using RLI's Biosync fuel additive with Chevron Premium 93 Octane fuel. Thanks for all of you help - I have been following this issue in oil guy forums.

interesting thread, I was thinking of replacing my B5 S4 with RS4 in couple years but this issue with carbon build up on intake valves makes me wonder if that would be wise decision.

besides warranty, what obstacles exit to have catch can venting to atmosphere instead this fancy cyclonic oil separator that does not work?

If you are running Biosyn a change at every 5K thereafter is a slam dunk. If you want to run longer than 5K between changes, send a sample at 5K on the oil to Terry Dyson. He'll tell you how much longer you can run the oil safely. He'll also tell you the state of tune your engine, and any other issues that need to be taken care of.

besides warranty, what obstacles exit to have catch can venting to atmosphere instead this fancy cyclonic oil separator that does not work?

If you do not supply a negative pressure to the crankcase (i.e. by drawing air through it from the airbox into the intake manifold), it will over-pressurize, especially during over-run. This scenario is frequent and the momentary pressure spikes will certainly start ruining all the gaskets between the crankcase and atmosphere (oil pan, valve covers, main seals etc). So instead of partially disassembling the engine to clean the valves, you will be replacing gaskets - some of which require removal of the engine. Additionally, regardless of the separation capability of the "catch" can, there is going to be an oily mess somewhere and if its anywhere near a hot part of the engine, the escaping vapor will be cooked and the resulting stench will remind all nearby motorists of their grandpa's oil-drinking pickup truck. Venting to atmosphere may suffice for race engines, but not a daily driver. I suppose this opinion could be tested by disconnecting the ventilation hose upstream of the cyclonic separators (don't forget to cap the inlet into the separator to avoid a massive vacuum leak) and going for a 5-minute drive.

If you are running Biosyn a change at every 5K thereafter is a slam dunk. If you want to run longer than 5K between changes, send a sample at 5K on the oil to Terry Dyson. He'll tell you how much longer you can run the oil safely. He'll also tell you the state of tune your engine, and any other issues that need to be taken care of.

Thanks ... wil do. Should I follow the same program (and oil) in my wife's '09 TTS (2.0 2TSI) or use a different RLI product?

Use exactly the same program with the TT

If you do not supply a negative pressure to the crankcase (i.e. by drawing air through it from the airbox into the intake manifold), it will over-pressurize, especially during over-run. This scenario is frequent and the momentary pressure spikes will certainly start ruining all the gaskets between the crankcase and atmosphere (oil pan, valve covers, main seals etc). So instead of partially disassembling the engine to clean the valves, you will be replacing gaskets - some of which require removal of the engine. Additionally, regardless of the separation capability of the "catch" can, there is going to be an oily mess somewhere and if its anywhere near a hot part of the engine, the escaping vapor will be cooked and the resulting stench will remind all nearby motorists of their grandpa's oil-drinking pickup truck. Venting to atmosphere may suffice for race engines, but not a daily driver. I suppose this opinion could be tested by disconnecting the ventilation hose upstream of the cyclonic separators (don't forget to cap the inlet into the separator to avoid a massive vacuum leak) and going for a 5-minute drive.

when I say went to atmosphere I mean went both valve covers as well as crankcase so no pressure build up of any kind..source of vacuum for the breather from the engine can simply be just capped off, so no vacuum leak either...

this is set up I am running on my S4 currently for several years without any problems

I just changed my oil/filter at 15k and went with Syntec 15W40. Car is not a daily driver and I was planning to replace after around 5k miles.
Do you guys think that it is warrantied to switch to RLI BIO 15w40 sooner?

where does one buy this bio oil?

I just changed my oil/filter at 15k and went with Syntec 15W40. Car is not a daily driver and I was planning to replace after around 5k miles.
Do you guys think that it is warrantied to switch to RLI BIO 15w40 sooner?

Those oils are a bit thick IMO.

At cold start the engine hydraulic actuators and adjusters might have a problem.

http://www.renewablelube.com/order.htm

Go for the Bio-Synthetic Super High Performance SAE 5W40 HD in the Gallon containers.

Those oils are a bit thick IMO.

Ok my fault. I mean to say Castrol Syntec 5W40 not 15W40.