Oily Mess Questions
 

Had the head gasket on my 92 300D replaced about 4,000 miles ago. The shop that did the work employs of couple of goons who made all manner of careless mistakes....had to take it back several times to get a variety of things addressed, one of which was an oily mess all over the right side of the engine. I was assured that this was due to the head gasket failure and that all would be well once they cleaned it up.

My son has had the car at college....just came back for the weekend. Lo and behold, the oily mess has returned and with a vengeance. BUT oil and coolant levels appear to be absolutely stable, so I'm thankful for that.

Since all levels are fine, is it reasonable to assume that the problem is exhaust related and nothing to be overly concerned about? Realistically, I probably won't be able to deal with it for a while.

Exhaust leaks leave a sooty mess that needs to be scrubbed off. Recent engine oil residue usually comes clean with a spritz of brake parts cleaner.

If it's on the block below the exhaust manifold gasket, it might be leaking valve stem seals. How does it look around the turbo oil supply fitting on the block? How does it look where the drain pipe attaches to the turbo? How's the area around the chain tensioner? Is there a tensioner crush washer in the replaced parts list? Take a torque wrench to it to make sure it's tightened to spec.

How's the hood pad? I forgot to replace the oil filler cap once and it soaked a corner of the pad. Years later it still leaves oil on the rubber strip atop the air cleaner barrier.

Sixto
87 300D

Here are some pics....may be kind of difficult to make out what I'm describing.

Do you have time to remove the air intake snorkel? That should allow more even lighting. Maybe hold the camera against the air cleaner barrier and shoot blindly towards the thermostat.

There seems to be some oil where the mixing pipe attaches to the head. Oil there can only come from a leaky valve cover, which looks dry.

Oil on the thermostat and alternator probably comes from the chain tensioner or #1 exhaust runner. Or, and hopefully not, the new head gasket isn't holding around the typical failure point.

Sixto
87 300D

Unfortunately, not able to devote time to it today....and my son takes car back tonight. And I cleaned it up a bit after those pics were taken. However (and this gives me a sick feeling), it does seem to be particularly oily where the block and head meet on the front right side. Ug. The thought of taking it back to the place where the work was done is more than I can bear.

Hmmm. Leaking timing chain tensioner...?

:stuart:

Is the chain tensioner the cylindrical thing in front of the exhaust manifold? Very, very oily just beneath it.

It's in the center of your second picture. Big bolt that screws into the block in line with where the water pump attaches to the thermostat housing.

Turn it only by the wider flats close to the block. Don't touch the narrower flats on the outboard end.

Sixto
87 300D

Are you suggesting I try to tighten it?

If it is a leaking tensioner, is this in the category of a messy annoyance until I get it addressed or is there some urgency?

You need to determine if the leak is from the tensioner, or from the head gasket itself BELOW the tensioner. The primary pressurized oil feed is in that exact location and it's a common place for OM60x head gaskets to leak oil. If the head is dry north of the block, it's the gasket leaking. If there is a lot of oil from the tensioner itself, could be the tensioner... there's supposed to be an aluminum O-ring seal between the tensioner and the head, sure hope they installed one.

:nuke:

A leaking tensioner might be of concern but the presumption is the leak is between the tensioner case and block, not between tensioner sections.

Sixto
87 300D

Spec is 80Nm which is 59 lbft.

Sixto
87 300D

Agreed. Note the tensioner screws into the cylinder head, not the block, btw.

:euro:

Well, hopefully with the head gasket replaced for a leak at that precise point the head gasket itself is fine. We'll see.

I'll just have to swap cars with my son so I can address it.

OK....I got curious. So I completely wiped clean the tensioner itself and the area of the head beneath it. So the whole area was clean and bone dry. Turned on the engine and it does not appear that there's any oil leaking from any part of the tensioner. BUT there appears to be fresh oil from under the lip of the head.

I think I'm going to be sick.... ;)