countryguy

The leak was isolated to be coming from a small drain hole at the driver's side of the engine near bottom close to the transmission.

Mechanic who found the leak does not know what's causing the leak.

Does anyone know what could be the cause of the leak?

Thx.

Carsy

Is it engine or transmission oil ?. Could be engine rear crankshaft oil seal leaking.

harkgar

A photo would help.

For 2008 MB transmission oil is red.

If it is leaking from an oil drain hole change the copper washer and see if it helps.

countryguy

There is no red, the leaking fluid is black as engine oil - diesel engine oil because it's as black as it gets :-)

Carsy

In my opinoin it is the engine rear crankshaft oil seal. Cannot understand why a mechanic could not diagnose the leak !!. That is his job.!

countryguy

Thanks.

avbar

Did you get this resolved? I've got the same thing on my 08 e320.

itaintoverever

I had my 2008 E320 serviced at the stealer recently, transmission filters and oil.
They said there was a leak at about the place described here. Said it is the oil cooler.
They quoted $3600 to replace the oil cooler assembly.
I looked up the oil cooler seals at Pelican Parts, $5.00.

avbar

Yep. The MB mechanic told me that it was my oil cooler too. He said it was a scheduled 15 hour service plus $250 in parts because they basically have to remove the whole engine to get to it. Total estimate was about $2700 in St. Louis. I have no idea what I'm going to do yet, except keep cardboard on my garage floor.

itaintoverever

I am thinking the Stealer here is off. I had an oil spill (changed oil and missed the correct place where the o ring goes) and got a bit of oil on the engine. Even after spending all day and the next cleaning up the spill I am sure that was that oil they spotted.
I pulled the plastic pan off under the engine and it was clean last week.
Note to self - don't do anything with this car without careful research!

N_Jay

I had a similar issue.
I got the oil cap on my GL320 a bit lopsided and it spit out about 1/2 quart or more of oil on a 200 miles drive.
The oil was all over the bottom of the engine and well soaked into the padding.
The dealer was "sure" I had a bad oil cooler seal.
I may have a few slow oil leaks but nothing that NEEDS $2K in repairs (yet)

SmokinReefer

I just had the dreaded oil cooler leak repaired on my 2010 ML with 100K miles. It too was leaking out of the small hole in the rear of the engine. Took 2 days and $4,400 to fix. Since I just ordered another ML (gasser this time) they knocked it down to $3,600.

Parts guy said the cooler has been redesigned with higher temperature seals.

I think the better mileage of the diesel is offset by higher maintenance costs so I went with gas for the new one. I'm keeping the diesel though.

And last month I had to replace the AdBlue tank heater for $1,500 to get rid of an annoying CEL