94 C220 Rough Idle - Interesting - PeachParts Mercedes-Benz Forum

jason490 · #1 03-26-2009, 01:52 PM

Hey Guys,

I have posted on this awhile back, but some new things have come to light. 1994 C220 with about 120k miles on it. The idle is rough and car misses, surges. I have replaced the MAF, plugs and wires, OVP, countless other things. I am just starting to notice a few other things, it only starts when I turn on either the AC or the Heat. Also if you are going up a hill or anything with the heat on, you hear a whistling through the vents, like a vacuum leak. I have looked and see none, do these symptoms ring a bell for anyone?

Thanks for any help guys.

Jason

porkface · #2 03-26-2009, 08:14 PM

the vacuum leak is in the heat/ac system in the dash. 1 of the servos has a hole in it.

the idle issue could be the engine and/or throttle body harnesses. very common to see crumbling insulation on the outside of the main harness. i just replaced a throttle body on a 95 c220 and opened up the harness to it. just bare wire and lotsa flakes. the owner said the car never ran better in the 3 years he's owned it. worth a look. good luck, chuck.

david s poole · #3 03-27-2009, 12:24 PM

i also just replaced a throttle body on a 94c220.the owner has had since new and makes the declaration that it's now as good as new.

jason490 · #4 03-31-2009, 08:20 AM

sorry for the slow reply guys, been out of town. I will definitely take a look at all of this. The servos in the dash, how would one go about getting to that?

Thanks again fellas,

Jason