I had/have a high idle problem as well but not as bad as above. I have replace the hoses and the ICV. So far I have the neutral idle down to about 1050 and the in gear idle (my 16V has a auto) to about 800 or so. I am not sure what else to do. Tied of throwing money at it for incremental reductions on idle.

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2014 C250 21,XXX my new DD ** 2013 GLK 350 18,000 Wife's new DD**

- With out god, life is everything.
- God is an ever receding pocket of scientific ignorance that's getting smaller and smaller as time moves on..." Neil DeGrasse Tyson
- You can pray for me, I'll think for you.
- When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.

It's worth making sure the idle contact switch on the linkage is connecting properly, and also I suppose the one in the throttle body too. The fact that there are 2 of these, plus 2 air temp sensors, 2 coolant temp sensors (4 if you count the fan switch and the dash guage) shows what nowadays we regard as a crazy system. At least Mercedes fitted it with failsafe 'default' modes, and seem to use high quality sensors and wiring that doesn't fail often. Broken wiring is not unheard of though so worth checking if those switches do work that the signal is repeated at the ECU connector end.

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg