Mercedes PCV valve = "A.I.R." system??

[sky jumper]

I have an '01 Mercedes S500 that is beating the heck out of the oil. TBN 1.9 after only 6k miles w/ M1 0W40. I tried checking the PCV valve, but the dealer says it doesn't have one - instead it has an air pump in the crankcase.

so I looked up online on one of those "genuine OEM parts" places, and they sell something under "Emissions Control" called the "A.I.R. pump" and an associated "check valve". would this be analogous to a standard PCV valve?? if so, does anyone know how to replace it?

Thanks!

 

[JTK]

Hmm.. almost sounds like they are mixing up their parts? My trailblazer 4.2L I6 has an A.I.R. system = air injection reaction. Basically it's a hair-dryer sized 12V blower under the truck that steals air from the aircleaner and blows it through a check valve into a port in the cylinder head just above the exhaust manifold.

Joel

 

[sky jumper]

do you know what function it serves? sounds like maybe it's forcing clean air into the crankcase to expel the combustion gasses (but where? and through what?). if the mercedes is doing the same thing, a bad check valve might choke the oil??

 

[JTK]

Quote:

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do you know what function it serves?..

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On mine, the AIR system force feeds filtered air (oxygen) to the catalytic converter to speed light-off and increase cat efficiency. On your benz, I have no idea. I can't see pumping air into a crank case. Maybe a vac pump to draw out CC vapors? Dunno. PCV valves use manifold vac. Is your benz a diesel?

Joel

 

[sky jumper]

no, it runs gasoline.

 

[unDummy]

Wow, it has a vacuum pump on the crankcase.

If so, then you should test the pumps output, any checkvalves, all hoses for leaks, and any filters that it might have. You'll need a factory service manual for that, or an experienced mechanic.

 

[JHZR2]

The M42 engine in my BMW has no PCV valve - just a straight run from crankcase to intake... It doesnt have any electronic assist, nor any fresh air, but a PCV (or EGR for that matter, as the engine doesnt have one of those either) is not necessary on any sort of engine, even to keep good emissions qualities...

JMH

 

[Kestas]

My 95 E320 has no pcv valve, just some magic plumbing at the block that I don't understand. I took it apart once and found nothing to clean, just a little varnish on the surfaces.