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This may seem obvious to people familiar with this model. However I’m having difficulty identifying the exact name and also the procedure to repair this oil leak. The oil appears to be seeping from this “front valve cover” which is on the top front drivers side of my engine. I’m not sure I’ve identified this part correctly, but upon changing the oil on this car for the first time after buying it a couple months ago I just realized that oil was seeping. It seems that this part is just sealed with sealant rather than an actual gasket. Can someone help me determine this part and fix.
I would use brake clean and get all the existing oil and dirt off the area. Once clean and oil and dirt free, you will likely be able to pinpoint where the problem originates. Makes your job much simpler if you know where to start
In the first photo, There is a cylinder head bolt in the center of the photo, it is a bit blurry, but that seems to be the location it is seeping from. There seems to be two of these medium sized covers on either side of the front of the engine. It is the drivers side one that is the culprit. If you look close you can see it is coated with black oil grim there. It is below the oil filer housing, and behind the black power steering container, and below the connector in the photo. I will try to get better photos in Sunlight.
As mentioned, I think the first step is to spray the area with some brake cleaner then observe area to ensure that's exactly the source of the leak.
Airflow around the engine from the belt rotation and radiator fans can play tricks with leak sourcing.
From the pics, I would suggest checking:
oil filter cap (has an o-ring that can leak)
around the attachment of the oil cooler to the engine block (the rubber base gasket can leak, not uncommon)
the power steering pump reservoir rear o-ring and cap
both cam sensors and both cam phasers (adjusters)
Here's info on the cam stuff, as you check this bank you should also check the other bank.
Of the items noted above, IMO this is an important item to check as oil in the harness can cause big troubles. https://mbworld.org/forums/e-class-w...onnectors.html
Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts.
"Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts."
I had this issue. Open the metal bottom cover at the front engine, you may see something as my picture. Dealer fixed under warranty. MY2014 E350
Thank you blackhorse! Tired of the engine oil smoke in my garage since day one.
My 2014 M276 has been leaking oil since day-1 . My dealer was unable to locate any oil despite numerous service bulletins covering engine leaks. It's amazing how well trained some people are at ignoring evidence
Did you find out where the oil collecting on your steering rack really comes from...???
Originally Posted by blackhorse01
"Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts."
I had this issue. Open the metal bottom cover at the front engine, you may see something as my picture. Dealer fixed under warranty. MY2014 E350
Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts.
"Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts."
I had this issue. Open the metal bottom cover at the front engine, you may see something as my picture. Dealer fixed under warranty. MY2014 E350
This is the exact place my oil is ending up underneath the car. Unfortunately my car is no longer under warranty and I will have to do this repair.
Some bolts are unable to be torqued to spec properly after being used. They are one-time bolts as they stretch. If reused, you may leak again. Better to replace.
I'm with KEY08. I ocassionally spill more oil in this area while making oil changes than what I see in the OP.
I've had minor valve cover seepage in my 18 year old MB for many years. Doesn't seem to affect performance in any way, and any amount of oil "lost" is never measurable at oil changes.
Whenever I fix niggly cosmetic problems like this, I always seem to create worse problems in the process.
I concur. There is a lot of tear down(like R&R Intake manifold) to get at the covers. You won't know how successful your repair went until it is all put back together and road tested. If you didn't perform everything exactly correct (right amount of proper sealant, exact torque sequence and spec, etc.) you will be tearing it down again. Good luck though!
This is why my wife knows better than to ask me to do plumbing work around the house.... because I suck at it.
I’ve previously replaced head gaskets on Audi, bmw, and Mini Cooper. But never have I seen sealant used instead of gaskets. I am pretty confident in my ability to change those so I don’t see this as a problem. If anyone has the procedure on pdf, please link it here. Also if anyone knows where to get a legit shop manual for this car, that would be much appreciated. I tried to use emanualonline but the files were in strange formats that couldn’t be downloaded using staples, kinkos, or any of those. No idea whether they are legit or not. I am trying not to splurge on a new computer as it could not download to my phone.
I’ve previously replaced head gaskets on Audi, bmw, and Mini Cooper. But never have I seen sealant used instead of gaskets. I am pretty confident in my ability to change those so I don’t see this as a problem. If anyone has the procedure on pdf, please link it here. Also if anyone knows where to get a legit shop manual for this car, that would be much appreciated. I tried to use emanualonline but the files were in strange formats that couldn’t be downloaded using staples, kinkos, or any of those. No idea whether they are legit or not. I am trying not to splurge on a new computer as it could not download to my phone.
Hi Mosesmorales,
I’m having the same problem. Did you manage to fix it?
Your leak is from the front cylinder head covers. It's the only common leak on the M278/M276 engines. They use the Mercedes Black sealant but for whatever reason they leak. Just reseal and make sure to replace the aluminum bolts.
Hi MBENZTECH,
Do you have the procedure to fix it? It will be great if you share it.
I was just told my 2016 S212 e400 has leaking front covers. (it was in for the steering bolt recall). Is silicone (RTV) enough of a sealant, or is there some aerospace goo that has to be applied in a vacuum?
05-09-2019, 01:20 PM
oil leak smell
