Oil leak help

[Whybother?]

Hi all,

Would appreciate some help with resolving an oil leak. I have a 2002 B5.5 Passat Sport estate, 1.9, 130 bhp - engine is an AVF with a 6 speed transmission. Some 20,000 miles/2 years ago I decided I was going to try and keep this car for another 10 years. At great expense I had the engine reconditioned, new cylinder head, new clutch and DMF, new turbo, intercooler, tandem pump, exhaust, EGR engine mounts etc etc amongst all the other ancillaries like N75s etc. The engine came back with an oil leak the firm flatly refused to put it right, said it was nothing major - saying that all cars of that age leak - errr...even ones which have just been reconditioned? I persevered with them but got nowhere and didn't have the resources to take it further. So 2 years on (and several attempts at rectifying it) the leak is still there and getting progressively worse. I had the crankshaft seal done about a year ago as that seemed most obvious as the oil is dripping off the bottom of the timing plate behind the front engine mount - my mechanic said that would be the most likely culprit. When that didn't solve it, we looked further up. Cheapest next attempt was a new head cover gasket (all things which had been changed with the recon). Didn't work so last week I had the camshaft seal done. Still leaking. Looking from underneath the engine the gasket paste between block and sump seems plentiful and oozes out of the joint. From what I can see from the top behind the timing plate, the side faces of the cylinder head seem like they have a film of oil coating but nothing too much - certainly not dripping or anything. So my question is: apart from the join between the head and the block and the block and the sump is there anything behind that plate or elswhere at the front lower part of the engine which could leak oil. These two joins seem like the last two possibilities having tried everything else - or is there something I haven't thought of? As last resorts both of these seem like they'll be costly and difficult to repair (sod's law it's the last of the two options) given the thousands already sunk on this engine. Any ideas other than these anybody? Thanks.

[Rob69]

I can't think of anything obvious in that area that you haven't already tried. Have you considered using a UV dye in the oil and seeing if you can pinpoint the source with a UV torch.

[Whybother?]

Thanks - only just learned about that possibility by reading through the forum here. Thanks for the tip. Will try that next.

[MiniMental]

Front cam bearing cap can leak if it wasn’t sealed with proper liquid gasket. Would tend to leak around the cam seal if it were the case. Wouldn’t imagine it to be a big leak however.

Would also say check your PCV is working, not sure how to test it as it’s built into the rocker cover but if it fails or gets blocked, it could increase pressure and push oil out of the seals in the head. Be it rocker cover or cam. New won’t make a difference if there’s positive pressure in there at an excessive level...


54 Passat Wagon PD175
99’ Audi S4 Avant 2.7 QTO

[Whybother?]

Thanks for this response - makes a lot of sense. I've heard different things about the PCVs on TDIs . The consensus seems to be that you can't service them. I know from having had the valve cover off a few times that these are integral to the cover and can't be removed but the distance between input and output is only a couple of inches. Wouldn't a blast with some cleaner be worth a try? Also I've had someone say to me that it's just a gauze mesh inside. My sense is from the discussions here of getting stuck open (suction) and closed (blowing) that it is actually a mechanical open/shut valve. Anyone confirm? Anyone had any luck freeing one up that has gotten stuck. I know the replacement rocker cover is close to £150 from VW - ouch! Thanks for the advice so far - feels like the scope of the problem might be narrowing down...