presistent oil leak Mk 5 2.0 TDI

[dtmini]

Hi all,My Golf runs out of warranty mid October this year. This car had an oil leak which was noticed at the first service at 15000 ks. Lennock Motors Canberra said the leak was in the sump area.The sump was removed and refitted with new sealant. The car has now only done 25000ks . Before the oil and filter were changed at 25000 ks my local mechanic rang me and got me to come and have a look while the car was still up on the hoist.There was quite a lot of oil everywhere. The whole area was degreased, the oil and filter changed and the under was NOT refitted. I drove the car for a 100ks put it back on the hoist and tried to see where the oil was coming from.There was oil wetness all around the bottom part ot the plastic piping from the turbo to the intercooler. The mechanic seemed to think that there may be a problem with the turbo. Have any of you had this problem? Any ideas? Thanks in advance,Dennis.

[Maverick]

Hi all,My Golf runs out of warranty mid October this year. This car had an oil leak which was noticed at the first service at 15000 ks. Lennock Motors Canberra said the leak was in the sump area.The sump was removed and refitted with new sealant. The car has now only done 25000ks . Before the oil and filter were changed at 25000 ks my local mechanic rang me and got me to come and have a look while the car was still up on the hoist.There was quite a lot of oil everywhere. The whole area was degreased, the oil and filter changed and the under was NOT refitted. I drove the car for a 100ks put it back on the hoist and tried to see where the oil was coming from.There was oil wetness all around the bottom part ot the plastic piping from the turbo to the intercooler. The mechanic seemed to think that there may be a problem with the turbo. Have any of you had this problem? Any ideas? Thanks in advance,Dennis.

I take it VW have only looked at the problem once?

I'd book it in and get them to sort it out and consider spending the <$1500 on the 3 year extended warranty as well.

[peter]

Hi Dennis,
Mine had a similar issue and it was diagnosed as just a bad seal on the lower intercooler pipe between the turbo and intercooler, as is on your's.
Because (and obviously) there's positive pressure in there, any oil that accumulates will be pushed out of leaks in any of the seals.
If the oil isn't excessive, it may have just accumulated from PCV vapours, which is normal -- folks have reported a fair amount oil from that, and some have installed catch cans to capture and take care of that oil. However, it's also possible that the oil may have come from the turbo if there really is a leak there.

I can't remember exactly how much oil loss (generally & not from the turbo) would be acceptable. But, if it was my car, I'd probably only start to worry if I'm having to top up 0.5-1L after 5000km of normal driving, which isn't anywhere near that on mine at the moment. It may even be acceptable to have to top up more than that. Anyone who's in the know: feel free to quote figures. Might also pay to do a search of the forum/s for acceptable amounts of oil loss.

Unclipping and reseating the hose unions may settle the seal too. After the seal was replaced on mine, it was still leaking a bit. So I unclipped it, jiggled it and reclipped and since then it's never been more than a small weep.

BTW, the problem was close to 55000km / 4 years ago.

cheers
Peter

[Greg Roles]

It's crankcase blowby oil, coming from the tappet cover, across the small U shaped tube and entering from above, just prior to the turbo in the inlet. I have been running an extra oil seperator since brand new, and I was still getting some weeping via the intercooler plumbing, and the insides of the pipes were oil coated. Hate to think what stock cars ingest. It's a major problem in high compression diesels I'm afraid, lots of compression equals lots of blowby. No major concern in itself, apart from the mess it causes, and the oil use over time.

What IS of major concern is all that oil mixes with the EGR exhaust gas ( soot ) just prior to the manifold, and creates a major sludge that gums everything up, narrows the inlet and begins to cause problems over 100k kms. I'd highly recommend getting an oil catch can / Provent / Allards or similar if you want to keep your diesel beyond those sort of kms.