Preventative Engine Mods?

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kid-jensen

MB Enthusiast
Joined
Dec 16, 2002
Messages
1,239
Location
Epsom Downs
Car
ML 320 W164
Still in the honeymoon period with my '07 ML320.

Being paranoid, I did a Google search for an engine description and Wikipedia came up with these worrying comments :-

"this engine (OM642) can also have an issue with the design of the positive crankcase ventilation system. The crankcase ventilation system vents to the inlet of the turbo. The issue is that the air vented from the crankcase contains too much oil to easily pass through the swirl motor valves downstream of the turbo. Once this oil and sludge begin to accumulate, the valve becomes inoperative and blows a fuse that controls many other sensors required to properly operate the engine and emission system. This will immediately place the vehicle into limp home mode and limit the rpm to 3000. It also causes a check engine light and numerous OBDII Codes. Mercedes Benz has previously recognized this feature of the vehicle and has stated that this engine feature, the accumulation of oil at the turbo inlet, is "normal".

Anyone know anything about this, and should I be worried?

My old Audi had problems blowing oil-laden crankcase fumes into the inlet so I fixed it with a catch-can. I wonder if this simple mod could be done on the ML engine?
 
I also read that a couple of months ago and it bothered me as well ..maybe a boffin will come and dispel this as scaremongering or bust our bubble lol.

Alfie
 
Venting upstream of the turbo is not uncommon , like the catch can idea.
 
Your car *should* have had the crankshaft position sensor (CPS) replaced due to a manufacturing defect. My 2007 Vito has the same engine, but they weren't recalled :rolleyes:

When the sensor fails the engine stops dead without any warning at all and can't be restarted (not the normal CPS issue of occasional cutting out when hot but OK when cooled down).

If you can easily access the sensor on the ML (towards the rear of the crankcase, nearside) it might be worth checking. The part number on my new one was MA642 905 00 00.
 
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