that_tg

Had the skid plate off and noticed oil on garage floor. It is in the same place you would have a coolant leak on a D2 with a bad oil cooler pipe. passenger front.
Any help to where I should start would be great.

Mike141

Was this ever diagnosed or fixed? Took my belly pan off today looking for a leak and it looks just like this one. Anyone have any ideas? My mechanic is doing some research but couldn't tell for sure where it's coming from.

hunterp27

Boy oh boy are you in for fun times ahead. I hope you don't have to go thru all of the hassle that I did with my S8. Granted the motors are very different and it could be coming from something totally different. Unfortunately, a lot of the time you cannot diagnose these things until you can get your eyes onto the problem spot. In my case, this required taking the whole front end off the car and confirmed the worst of all cases......a breach at the block and upper oil pan. I truly hope yours is something less invasive and can be fixed without removing the whole dang motor. In the case of the V10, in order to access this particular leak, the transmission had to be decoupled from the motor, then the back timing cover removed so that the upper oil pan could be removed. This major surgery cannot take place with the motor and transmission in place. Now, with all of that remedied, I am chasing other more common failures like fused replays that wont allow your air suspension compressor to shut off. Dreadful design by the Art boys.

Panelhead

With engine running pull oil fill cap. See if it is blowing or sucking air. If sucking keep looking. If blowing replace the crankcase vent valve.

Mike141

Thanks, I'll check that out....would that cause a leak?

MP4.2+6.0

As a suggestion, your issue merits a new thread, but up to you I guess. You should also identify your year and motor. I remember that (I think) from the coolant question, but it's not here except by guessing since you posted into a 2007 FSI thread. Best if in your signature or avatar.

Yes, pressurized oil system could cause leak. More an S8 specific issue if I remember old posts, but used to happen (rarely) on prior generation 4.2s (and more toward A6 side) due to a couple of sometimes faulty parts.

More likely just thinking about general 4.2 set up (back to my A6), I would probably suspect stuff around the oil to water cooler set up; also I don't know enough about how the oil filter moved around on the later 4.2's. Why a fresh post could help too from other D3 4.2 owner experiences. I would also not dismiss the valve cover gasket. The most common oil leak spot on any of the motors (though more in the back corners) and it can run down and all over stuff, especially with normal air flows at speed. More so maybe if it's a 2007/early FSI IIRC. Several posts in last few months that brought out that there were issues with the early motors and the gasketing, eventually leading Audi to entirely rev. one of the covers--if I am remembering the threads from last few months.

Net, will likely need to pull belly pan if it is lower down, probably clean it up if leak source isn't apparent (look at highest point and where it is most pronounced). Then run it some and see where it reappears. If you want to wimp out on belly pan and getting underneath at first--and yet more so if it is 2007 FSI 4.2--at least wipe whole perimeter of valve cover gaskets (both sides checking won't hurt) and see what you find and/or if something comes back.

Mike141

2007 A8 4.2FSI...took belly pan off other day, the bottom of my engine looked just like the OP's. I did my last oil change in Sept, and bottom of engine was all dry. Not clear where it's coming from exactly, somewhere in the front of engine though. Valve cover areas are dry. I've read that some people have had the oil filter housing gasket fail which will then run oil down under intake manifold then down front of engine.
Also read a bad crankcase vent valve could possibly cause an oil leak...I did what Panelhead suggested, there was a strong suction on oil filler cap and once removed, engine seemed to run rough. Any ideas on the valve?
I'll be looking. Car only has 77K and runs excellent. Hope to keep it that way for a long time.

Panelhead

.I did what Panelhead suggested, there was a strong suction on oil filler cap and once removed, engine seemed to run rough. Any ideas on the valve? [/QUOTE]


The valve is working properly. This is not the cause of your leak. This is the easy fix, 33.00 from Partsgeek and a 30 minute job to replace.
The drill now is to clean the motor and try to find where the oil is coming from. Oil leaks can be very tricky. The source does not show much.
Start at the bottom and work your way up. Begin with oil pan gasket. If it is the filter housing it should be easy to locate. But, really go over the valve covers. Most likely this is it. Put on a pair of white cotton gloves and wipe all the way around. Or as well as possible. If the leak is below the valve covers and not the oil pan it sounds expensive to repair.

MP4.2+6.0

From what you have said, next low hanging fruit is the oil filter housing and gasket. More so with no oil leak back at oil change, but then oil mess now. I would clean area all up and look for leaks, and likely just preemptively change oil and filter to be done w/ that, plus of course change o ring at same time. At least the filter and o ring as soon as you open the housing to check.

Mike141

Well, been doing some research on this issue and have found others have had their PCV valve or crankcase ventaliation valve freeze in extremely cold temps. A few weeks back here in CT the temps were in the negatives. While it is garaged but while at work I noticed several times I would get a whistle from the engine upon leaving, indicative of a clogged or frozen PCV. So, I'm thinking the oil had to go somewhere due to the blockage. It's not the upper oil pan...it appears higher than that. Going to clean it up and swap out that pcv.