Top End Oil Seep M272

[E55BOF]

The car is a 2008 CLK 350 - W272 engine; 125K miles under the wheels, but it's the quietest engine I've ever had in a Mercedes.

There's a smell of burnt oil in the cabin when the heater fan is running, and I know why; there's a slight seep of oil dripping on to the L/H exhaust manifold, and the little bit of smoke produced is being drawn into the cabin. Probably the cam cover seal, I would think, but is there any other likely cause? Anybody had this, and what was the cause?

 

[KeithDee]

I'd of thought the same as you, a leak from the cam cover, is the engine crank case breather ok, no leaks but that would be more of a fumey type smell than burnt oil I'd of thought

 

[E55BOF]

I can actually see the wisps of smoke coming up at that corner of the engine.

 

[E55BOF]

It's a well-documented characteristic, as it turns out, on the non-CGI M272s; there are what are rather like core plugs on the rear face of the engine, plugging the camshaft and (presumably) balancer shaft line borings in the casting. One or other eventually leaks slightly, hence the smoke.

Replaced both today (very simple job), and no more wisps of smoke, and the smell is fading. Job done.