low idle RPM - PeachParts Mercedes-Benz Forum

inventor · #1 03-12-2012, 03:43 PM

Hi, I have a 1994 S350 and just rebuild the turbocharger, before the rebuild the rpm was at 650 always now that the turbo is working normal the rpm is at down at 400 I don’t know what is causing that? Some times at start up (warm engine) is running at 650 and sometimes at the traffic light it runs at normal 650 rpm the question is where do I start looking for what might be causing this?

inventor · #2 03-12-2012, 04:24 PM

Quote:

Originally Posted by inventor

Hi, I have a 1994 S350 and just rebuild the turbocharger, before the rebuild the rpm was at 650 always now that the turbo is working normal the rpm is at down at 400 I don’t know what is causing that? Some times at start up (warm engine) is running at 650 and sometimes at the traffic light it runs at normal 650 rpm the question is where do I start looking for what might be causing this?

I forgot to add what I tried or check or fix so far instead of editing the last post.
I fix the EGR leaking vacuum line, remove and check vacuum control valve (not damaged) and fix the Fuel thermostat non of the repairs made any difference.