Persistent oil leak

[maddis]

I seem to have very persistent oil leak in 3B motor. It seems I finally managed to get camshaft seal to hold, but something is still leaking since car keeps marking it's place.

I've also changed oil pump and oil pan seals although I think the oil pan seal might leak since it was bit of a mess to put it back on. Also some previous owner has changed AAN style baffle(?) there so there is actually two seals and baffle between them.

Are there any common place where engine can leak oil? I think only place left are turbo's return oil pipe and that thing where oil cleaner connects although oil cleaner is dry so I'm guessing it won't leak.

Oil is kind a hard to clean so I'm not sure where the leaks source is.

After changing oil and oil cleaner I got much better oil pressure. Maybe even too good. With old oil/filter even with subzero temperatures I couldn't get more than maybe 4bar after cold start and when oil warmed it stayed around 3bar(or bit less) when driving. Now at -5C I get over 5bar after startup and it settles around 3bar(or bit more) after oil has warmed up.

[GazzaG60]

check the base of the dipstick

[maddis]

I checked the dipstick and the base was dry. I noticed also that bottom of the oil pan is dry as well. Bottom of the oil filter has little dribble, but way smaller than before the seal switch. Interestingly enough the bracket for AC compressor had two big oil dribbles ready to drop.

I couldn't get under the car to investigate more at this time, but I'm just curious that how is it possible that AC compressor bracket is wet, but still the oil pan itself is dry. Even if the oil pump would leak I'd suspect that it would leak also to oil pan.

Oh well, I'll have to investigate that more later.

[jade]

I checked the dipstick and the base was dry. I noticed also that bottom of the oil pan is dry as well. Bottom of the oil filter has little dribble, but way smaller than before the seal switch. Interestingly enough the bracket for AC compressor had two big oil dribbles ready to drop.

I couldn't get under the car to investigate more at this time, but I'm just curious that how is it possible that AC compressor bracket is wet, but still the oil pan itself is dry. Even if the oil pump would leak I'd suspect that it would leak also to oil pan.

Oh well, I'll have to investigate that more later.

Check the big bolt that holds the oil filter housing is troqued correctly and is not leaking at the seal

[Donnie]

Oil pressure sensor on the block - total ******* - leaks on every vw/audi through the plastic center.

[macspring]

Agreed, replace it now even if it is not leaking yet ! ...

[maddis]

Where is it? In the thing where the oil filter connects also? I tried to look for oil pressure sensor from vagcat, but couldn't find.

[UrS4boy]

Where is it? In the thing where the oil filter connects also? I tried to look for oil pressure sensor from vagcat, but couldn't find.

This should help you look: http://forums.quattroworld.com/s4s6/msgs/96161.phtml

[maddis]

Okay. I think I'll find it now. Will check it on this evening. Looks promising source for the leak.

[Donnie]

Yeah its the switch that always leaks, the boot will no doubt be all spongey and rotten too. Its a total :corey: to get to cos of the water radiator. For some reason almost every audi I've owned has leaked here.

[Greg_S]

Yeah I have had to fix mine before now too, its not too bad to do if you disconnect the PAS pump pipe that goes through cowl so you can remove cowl and it becomes a much easier job then

[maddis]

I checked those sensors including the oil dipstick pipe root and they all looked dry.

It seemed that oil pump might leak somewhere near AC compressor bracket. I'm not sure since the space is so tight.

I'm thinking of replacing the turbo oil return line seal and that seal that is between engine block and that thing where oil filter connects. They seem bit damp too, but major leak is on that other side.

I'm kind a positive that those sensors are not the cause this time although they can leak later.

And I thought I did good job replacing the oil pump seal, but had much more troubles with oil pan seal and now the oil pump seal seems to leak.

[JariP]

The rear AC compressor bracket covers a turbo oil return for the engine without AC. There is an o-ring under the bracket, could that be the leak?

[maddis]

Well, I just told that I have AC so the return line for the turbo oil is on the other side of the engine. And I think the feedline for the turbo comes from the same block where the oil filter is, if I'm not mistaken.

It's so tight squeeze between AC compressor bracket and engine block that I don't think that there is anything between.

[Thuppu]

I think JariP means that you have a cover with a O-ring on the turbo return hole which is used on non-AC-cars.

Edit. Found a pic from the gallery: