I have 1999 C230 with a CEL and P0170 code, which points me to the Air Mass Meter sensor. So I removed the AMM to clean it with CRC MAF cleaner. It was soaked with oil. The pipe coming from the air cleaner also has oil all over, and one of the large hoses coming into the air cleaner box is coated with a black tarry film.

I sprayed the sensor down with the cleaner, and now the engine runs better (for now), but where could the oil be coming from?

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2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic

Some line is clogged, maybe even your PCV valve. That hose feeds hot air into the air filter area during warm ups, either directly from the crankcase or from the manifold area. My sincere apologies, I just don't know about the specifics of your motor

Check crankcase oil level for over-fill.

Thanks for the advice (this is a great forum!). I checked the oil level a couple of days ago. It's due for a change, and at the moment, it's about a quart low, so I assume that rules out overfill (or does it?).

Maybe I should look for the clog that ASaltyDog mentioned.

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2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic

That rules out over-fill, but if the oil is ready to change and thin/low, you may have a little blowby [ specially w/kompressor], so an oil change may just do it..
I would start there and monitor it..I would also check the condition of the air filter.

chances are as mentioned above the pcv system is malfunctioning, the oil seperator is likely not working properly, large black unit on pass side of valve cover area

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1967 250 S
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1983 300 SD
1985 230 TE euro
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1987 560SEL
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2005 C230
1998 C43 AMG Sold to DON
1993 190E 2.6
300TD Former daily driver Totaled
current:
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the oil is coming from IRAQ....thanks to the war....lol.....


i liked ur title, " Where is all this oil coming from?"....couldn't resist

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just joined in order to check whether or not I'm getting the run around from the local Mercedes"expert" - less than a month ago they repaired a broken vacuum line, when the check engine light was reported to them during the 150,000 mile service. Two weeks later she began to stall and we barely got her back there. reportedly the crankcase ventillation leaked "somehow" and "stopped up", causing oil to shut down the air mass meter - this will have to be replaced (I'm glad I see the $300 above from last year) @about $388 (plus replacing a hose.

Anybody out there have experience with these guys? Did they screw up the crankcase during service last month? Or simply time for the crankcase to cause this? Any opinions?

Thanks

OK, this car does not have a PVC valve. I went to the dealer and tried to buy one. The parts guy looked it up and couldn't find it. It does however have a crankcase vent valve, which is pretty much the same as a PVC valve.

It's located under the intake manifold on the drivers side. It's pretty much impossible to see, and is connected by two rubber hoses going to the engine. He had to remove the manifold to access it. All the rubber hoses were cracked and needed to be replaced. The ports where the hoses connected were completely clogged. He used a drill bit to ream them out by hand (very difficult to get-to).

The engine runs fine now and the oil problem has pretty much disappeared. A $20 valve solved it.

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2008 ML350
2007 Honda Element
2007 Honda Accord
2009 Honda Civic

I ma happy that you found the solution.

Can you post pictures it wouild help?

Regards

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