bstone

Hello-

This morning as I was pulling out of my street, I started getting a loud valve noise. Not the typical quiet tapping, but pretty significant. Drove about 3 blocks and turned around and parked it. Running fine, no issues other than the noise. Doing some research, I have read that there are oil pressure/check valves in each head that can go bad. Can anyone confirm this, and if so how difficult it might be to change them? I understand you can get to them just by removing the valve covers.

BTW, oil level is fine, and no low pressure lights have been on.

Other thought is cam tensioner?

Thanks-
Brady

bstone

After doing more research, seems like it could also be lifters... anyone have any thoughts? Could really use some advice here...

Rusty Spokes

Randomly, yes the check valves will cause problems as will the lifters. You may not have an oil pressure warning lamp on..but those old oil pressure switches may not be working too.

Best first step..indicate year and engine in the A6?. how many miles? What oil filter and oil viscosity? Is the engine very "sludgy" under the valve covers? Regular oil changes?

Second step..check the actual oil pressure..you have to know. A fiddly job to fit a mechanical oil pressure gauge in place of one of the oil pressure switches. You don't need a high end gauge..shop around..you will need the correct fitting.http://www.eastwood.com/oil-pressure...FcUdgQodsTMINQ

bstone

Thanks, Rusty.
Car is a 97 A6 2.8. Mileage is about 200K. Don't know much about the history, I haven't had it long. Was about to do an oil change on it. Pulled the driver's side valve cover, doesn't look particularly sludgy. Don't know the viscosity, but it does drink a bit of oil. I have been adding 5W30 when it has needed it. It doesn't burn or leak it, though. I did mis-speak on the original post about the oil level- I hadn't checked it prior to posting and I was out of town for the week before, but I usually check it often due to the consumption. it was almost a quart low, although I was sure I checked it before I left. I think it is a WIX filter- which I didn't install and wouldn't use going forward.

bstone

I'm a bit convinced that I have a bad lifter... after reading this and hearing the video. Mine sounds pretty much like that. I didn't notice any cam or lifter damage like his, but I only pulled the driver's side cover..

quattroworld.com Forums: Cam and lifter replacement PSA

Rusty Spokes

See if you can identify exactly where the noise is coming from..under the valve covers? A collapsed lifter makes a big racket..it can sound like a bad bottom end bearing too..very loud. A screwdriver placed on various parts and then held to your ear is a good stethoscope for exactly finding the source.

Wix is a okay brand..I use Mahle or Mann filters. And 5w30 is a little light for an older engine. I use 15w40 Delo.

With the engine running do you see oil splashing around if you remove the oil filler cap and look in there with a flashlight?

bstone

It's definitely a big racket. Far more than just the standard valve tick... I thought it was coming from the drivers side, which is why I pulled that cover. I also started it briefly with the cover off to see if anything looked odd- and there was plenty of oil moving around. Plus, in my experience typical valve train noise is just that- the whole train taps lightly- I always used to say it sounds like a sewing machine (at least to me). While annoying, not really disturbing. The noise I have is loud enough to be disturbing.

In addition, I re-pulled the codes- I have had a CEL for EGR valve for a couple weeks now, but I also now have a PO304- cylinder 4 misfire. Which again, seems consistent with a valve/lifter issue.

Given that the car was running well the day before, I'm thinking that this is less of an ongoing problem and more of a forgetful moment on my part in terms of keeping up with the oil level.

bstone

OK, so just to come full circle on this-
I spent the better part of 2 days over the 4th of July weekend giving the car some open heart surgery. Got everything put back together without any issues- except that the lifter noise was still present. After some sage advice from Rusty, it turns out that it really does take some time for the new lifters to pump back up to their normal level. Took 2 test drives on Sunday, and the noise was getting a bit better. 2 more drives on Monday, and the noise stopped entirely. Nerve racking to drive with the noise like that, but in the end that was the fix. So now she's back on the road better than ever, with new lifters, timing belt kit and water pump, and new tensioner and serpentine belt. I now have a lot more knowledge about the car, and I'm not out $1300 to the shop. If anyone has any questions on it, feel free to PM me. Glad to pass on the help that was given to me.

Rusty Spokes

bstone..for everyone that has had lifters making noises..it is alarming and can sound like rod knock or worse...it takes a while for lifters to "pump up" and a good long drive is the best solution. Nerve wracking drive for sure..and well rewarded at the end.