prachal

My 2007 ML 350 seems to be burning through oil. I now have to put 1-1.5 quarts in every 500 miles. She has 155K+ miles. The oil issue is my only one. Any thoughts regarding the cause of the problem?

sheepdog8

I'd check for oil leaks, could be some seals. My 08 diesel only has 83k, but I noticed I was having to add some oil pretty often. When I changed the oil, saw a leak. Dealer had to replace oil cooler seals then rear main seal. Problem fixed, oil now stays level. Researched & found MB upgraded seals from rubber to a high tech non degrading type, can't remember the name of the material. Unsure if your gas model has the same problem.
If the piston rings are worn. & burning oil, should be some smoke in the exhaust. When totally warm, stand at rear & have someone rev the engine, if smoke, that's not good. No smoke, Id say it's leaking. I never saw any oil on my garage floor, the underbody try's caught it.

49coupe

Oil consumption is a problem on some of the 3.5 and 3.2L V6s. Mercedes will give you the "this is normal", but that much consumption is too much. My guess is you have a leak or its burning oil because the rings are worn. That much consumption will damage your catalytic converters over time, so I would look into the problem. Not cheap to replace....

GregMN

Check for oil leaking into the intake.