Hey guys,


So I just got my W123 Diesel all sorted of oil leaks when I notice an alarming leak coming from my moms W210 1998 E320 with the M112. I pulled it up on ramps and could see oil dripping off of various lines, but could not find the cause.

I did some research and found a great deal of people who had encountered the oil test cover gasket leaking, and described similar oil leak symptoms. If you're not familiar with it, there is a little port cover bolted onto the front of the block just below the oil filter housing and just above the serpentine tension pulley.

I went out and wiped this little cover part clean, as it was filthy all around it. I ran my finger along it afterwards and had no oil on my finger. I then started the engine, and walked back around and ran my finger on the same spot. In the few sec it took me to get over there, my finger was now covered in fresh, hot oil.

I'm happy as this is a simple, inexpensive part to fix. However, in all of the reading I did on it, no one has a part # for it and I can't find one. Anyone out there who's done this job have the part # for the gasket to the piece and the little crush washer for the center bolt?

Thanks!

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1984 Mercedes-Benz 300D

Yes a common source of an oil leak on the M112. I don't have part no. but it is inexpensive ( < $5) at a dealer. It's a rectangular rubber gasket for the oil inspection/test port on the timing chain cover. A second common area on the engine is the upper part of the valve cover assembly. There is no gasket and a gasket forming adhesive is used.

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Good luck.






1998 E320 Wagon

Well I went by my local Merc indy and he knew right away what I needed and had quite a few in stock. I'm gonna do the job tomorrow. I've looked all over, and cant find any diy articles or anything on it, so I'm guessing it's a straight forward job.

Anyone out there who's done it feel that there's anything I should know? Or is it just unbolt, install new gasket and rebolt to torque spec?

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1984 Mercedes-Benz 300D

It's very easy. Some people do it without removing fan shroud or fan belt. Two torx fasteners. Just remove, replace gasket and reinstall. Generally, the center plug doesn't leak so that seal isn't needed. I was never able to find a torque spec. Just enough to compress the gasket slightly and recheck after driving.

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Good luck.






1998 E320 Wagon

Depending on how many miles on your car, you also might find that the gaskets between the oil cooler and oil filter housing have gone hard and are leaking. This is also an easy job however the two gaskets are ridiculously expensive.

There is another gasket underneath the oil filter housing that also eventually leaks. Also a simple job to replace providing you have a large 46mm socket to get the housing off.