I bought my ml350 bluetech used with aprox 100k on the clock. When I replaced the front diff oil, I noticed there was moly (CV) grease all over the pumpkin. The CVs looked fine, and didn't look like they were originally replaced, and there was no grease explosion on the lower plastic cover where the CVs are. It almost looked like it had leaked onto it from above, however in all my years of wrenching, Ive never seen moly grease used anywhere in the engine compartment, and the diff looked fine otherwise.

 

It's coming from one of the boots on that axle shaft. Carefully inspect both.

 

Boots are fine, and the stubs are clean. Distribution is asymmetric, top down. Volume is too much, unless it's oil mixed with water and some sort of solvent from cleaning the engine or repairing the oil cooler. I'll just write it off as one of the mysteries of buying a second hand car. Besides, now I get to deal with a faulty fuel sender

 

It's not been pumped in there to try and mask the sounds from a worn diff?

 

Nope, oil was fine

 

SOLVED: So the motor mounts on this model are grease filled, not fluid filled. Makes sense since the mounts are right above the diff.

 

Hi raceratb--so that grease you are talking about was gray in nature? I have the same thing happen on my Bluetec and have been wonder where that stuff came from! It happened a while ago.....is the motor mount bad then?

 

Yes is a medium gray heavy grease. I did not do the work myself, but according to the history the mounts were replaced and the mounts are directly above the diff

 

Ah I see. Perhaps mine was replaced too as well. I suppose the grease drip is normal then? Pretty sure I am not feeling any issues with the mount. Thanks again for your reply.

 

The engine mounts are oil filled, its a dark brown oil. The grey grease is filling the actual bracket that holds the engine mount to the block. They are known to leak. The grease is supposed to dampen vibrations as well.

 

Parts are called the "engine carrier"

Left: part # 642 223 3704
Right: part # 642 223 3204

 

Engine carrier, engine mount bracket, lets not split hairs on a two year old post.

 

Thank you. You helped me so much. I cant even imagine that mount carrier might have grease