Seems to be something going on in the 05 E320 wagon that after it is up to operating temperature, as long as it is in gear, it idles down about where it is supposed to be. When put in park or neutral the idle increases to between 2 and 3k and kinda swings around. When I put my hand over the intake at the MAF sensor (air filter housing is off) without letting the engine shut off it settles down and idles as it should.
This past weekend I cleaned the throttle butterfly along with the valve cover crankcase vent system and replaced the respective hoses. Still changing oil every few days trying to clean out the sludge. On a side note I have started nosing around for another engine
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I'll put the computer on it later on in the week as time allows.