danholm

Anyone had this problem. On my 91' 300TE the motor will not idle down at times. When driving or sitting still. I cleaned all the linkages and did no good. I noticed from the CD Rom service manual that there is a throttle position sensor. Don't want to throw parts at this, so checking to see if anyone replaced theirs due to this issue.

Thanks

d

Jim's500E

Could be a few things...throttle body gummed up inside, small vacuum leak somewhere? Doubt its the sensor but they are cheap and its worth a try; it could be that. Did you do a full tune-up lately with cap, rotor, plugs etc? Sometimes just those items alone makes the cars happy enough.

On Mercedesshop.com there is a great tech section staffed by factory techs...I bet your question would be better answered there as I am only a shadetree mechanic myself.

m117968

Air idle valves like to get sticky on these as well. How many miles on the car? Does it shift hard (or harder then it used to at least?).

A few more details and I'm sure we can help!

Jonathan

danholm

Thanks guys. Here are more details. 180K miles. I acts just like a sticky throttle. If I blip the linkage, most of the time it will idle down. Plugs, rotor, cap, wires and all that, are not that old. Don't know of an exact vacuum leak, but good call, cause it reminded me that the door locks are intermitent. However at startup the locks still don't always come back.

I would think that a vacuum problem would be consistent, and blipping the throttle would not make a difference.

Trans shifts as it should. Kick down is working as should.

Where is the air idle valve?

This was my wifes, and I got her a new car. I haven't driven it much until now. I can't believe she didn't say anything, because one has to ride the brakes just to keep off the rear end of others. I'm tweaking it before it goes to market. I'll probably sell it to a family member or someone I know, so I want to make sure I don't just do a quick fix.

D