w204 oil leak - any likely causes?

[leninsaccountant]

I recently had a full service done on my w204. The mechanic found a major oil leak coming from the rear of the engine, but because he was a mobile mechanic, wasn't able to immediately identity the problem.

I'm going to take it to a mechanic to investigate,but i'm just wondering, for people more familiar with the w204 and the engine that it uses, if there are any likely candidates for what this could be?

Thanks!

 

[Uncle Benz]

Without knowing which engine, it’s difficult to say. I’m going to take wild stab in the dark and say you’ve got an om642 320cdi, because oil leaks from the oil cooler seals are so common with that particular engine

 

[leninsaccountant]

Sorry, I should have given this information in my original post!

The car is a C220 CDI, using the 651.911 engine. To your knowledge, are perished oil cooler seals a common fault with this engine?

Thanks,
Ryan

 

[Alan_]

OM651 Engines, I believe can an Oil Leak due to a loose Timing Chain Tensioner. Other than that, Loose rocker Cover or Turbo Feed Pipe.
If it was at the front, odds on it would be the Oil Cooler.

 

[Uncle Benz]

Om651, yes timing chain tensioner can work loose and leak. Also the cam cover bolts come loose. Nipping them up usually sorts. The cap that seals the oil cooler thrmostat tube has an O ring that goes hard and can leak. Usually soaks the front anti roll bar that one.

 

[Steve@Avantgarde]

Rocker covers are warping for a past time now. Rubbish made of plastic. The other one is the oil cooler on the filter housing.

 

[alcmackew]

Just my experience and not wanting to scare you - oil cooler, oil switch over valve, engine sump were all leaking shortly after I bought the car from Arthur Daley Motors (very much like). The under tray was capturing the oil to a point then it was running out the sides so not easy to pinpoint in the driveway.

The engine had to come out to replace these items and whilst out had the thermostat, water pump and EGR & intake gaskets replaced as preventitive maintenance.

Car had 88,000 klms on it - common issues with OM651s (esp. if a meat head has been servicing it).

Runs like new since and almost at 130,000 klms! Cost about AUD2900 all up which I managed to claim 85% from the dealer as a claim.....