c200 clk auto, irratic reving (hunting) when cold

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nismo915

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I've recently brought a w208 clk 2.0 auto about 2 weeks ago. Its great and i love it but there's one problem with it.

From first start in the morning or when starting it to come home from work it revs itself irraticly from 200rpm to 2500rpm almost stalling.

when its warmed up a little after about 5 mins its perfect.

Anyone any ideas??
i've already replaced MAF.
 

television

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2002 SL500, 216 CL500, all fully loaded
I would clean out the throttle body with a carb cleaner, and check that all vacuum pipes are connected on the inlet manifold
 
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nismo915

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should it make a difference if its in gear?? it seems to rev more excessivley when stationary in drive or reverse.
 

Miffy

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sounds like a vacuum hose is lose. Engine is hunting. This only shows itself at low revs, and would appear worse when in gear as the engine will be fighting with the gearbox. But, this wouldnt normally go away when warm
 

television

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This fault is a bit odd and I would to look up the injection system switch points
 
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nismo915

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do you think something like this would bring up a engine warning light? i've never seen one on my car.
 

television

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No it will not bring up a light, as miffy's post an air leak could do this but that speed increase is a little on the excessive side
 
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nismo915

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I've read on other mercedes forums that the engine mounts cause rough idle when cold. is this right or have i mis-understood it?
 

rich.g.williams

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C200 CDI Avantgarde SE Auto May 2004 Sports Pack
sounds like an intermittent electrical fault near the throtte end.

best get it seen to urgently before it revs itself to damage.
 
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nismo915

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Had it plugged in today, it had 2 fault codes in it.

P82F6 & P50D0

Anyone any ideas please?:confused:
 

television

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I do not recognize those codes should be all p then numbers
 

geezer255

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Them codes arent from a STAR are they??
 
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nismo915

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not sure, a friend of mine said he had the right connector and software to read the ecu. He said they normally start with P then numbers and he didnt know what they were either.
 
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