ThaboTheWuff

So my A8 was sitting for 8 months, did get some driving but not a lot. I'm back and have been driving here around. I decided to add some R132a today, 90F, as the aircon was not blowing very cold air. Worked well enough (just added R132 no dye or oil) and I then decided to add some PAG oil just 2oz. The car has always had an oil leak but after added the oil I see oil dripping out from under the car at quite a rate (yes not very scientific) and seems to be coming from where the filter / oil cooler is housed. The oil leak before was just a drip, this looks more serious ??? So I'm wondering do i not have the dreaded $13 plastic pipe oil cooler leak as I'm sure adding the PAG oil to the aircon was purely coincidental. I DO NOT have any coolant leaking - strange.

ThaboTheWuff

Another theory, PAG oil dripping out of compressor, diluting the existing oil on the underside of car.( The underside is so wet with oil I dare not post a photo of it here). Will spray it off today and check to see where the real leak is coming from. Seem to of stopped or back to its usual amount.

the_duke

When that oil cooler pipe breaks you loose coolant and not oil. I'd be more suspicious of a valve cover leak. They get hard over the years of heat cycling and can leak pretty significantly.

nyrobbie77

Sounds like the oil pressure switch. It's located on the oil cooler housing above the oil filter. You should be able to see it from both top side and from under the vehicle. You didn't specify what year your car is, but on my 32 valve I removed the airbox for better access to remove. Not sure on the 40V. When mine leaked it was a good steady stream.

the_duke

Trying to remember but I don't think you can see it from the top on the 40v motor.

ThaboTheWuff

99 so I'll take a look. Seems to not be leaking so bad now. So much oil on the underbelly of car I can't see where any of the leaks are coming from

twentysevenlitres

Oil pans on these engines can leak after a time.
They use sealant not a gasket.

If you do need to reseal it, don't use silicone.
Get the right stuff or an equivalent (I used Toyota oil pan sealant). Loctite blue gasket maker will do if you get desperate!

silverd2

Actually, according to Audi, PFL (32v) used gaskets ... and FL (40V) use silicone sealant.

I've had my 40V oil pan off twice in the past (not for leaks) and resealed with Audi recommended silicone sealant ... no leaks before or after >>>

https://www.ecstuning.com/b-victor-r.../d176404a2~vr/

ThaboTheWuff

It turned out to be the oil pressure switch, super easy to fix ! And it appeared that this was the biggest culprit in my "oil dripping on the driveway" issue that I've had for the past 5 years or so! Wow another feature of this fine vehicle!

Will post video.