Strange Idle Behavior. - MBWorld.org Forums

Jun 8, 2010 | 10:11 AM

360º

Thread Starter

Member

Joined: Mar 2009

Posts: 89

Likes: 0

2008 ML550

Strange Idle Behavior.

When sitting at a red light the RPMs sometimes dip and the car starts to vibrate a little and then it goes back up.

other times the RPMs spike up past 1200 almost like someone is gently reving the engine.

dont bother suggesting i take it to the dealership, not an option right now

im looking for answers here

Jun 8, 2010 | 10:37 AM

KA8

Senior Member

Joined: Jul 2007

Posts: 389

Likes: 4

2002 E430

hmmm... sounds familiar. Was your ac on? I have similar symptom with the ac on. If it is I'm thinking it's related to ac compressor. Just dropped it off at the dealer yesterday for ac and other problems.

Jun 8, 2010 | 12:26 PM

Benzo 003

Senior Member

Joined: Sep 2009

Posts: 361

Likes: 3

From: Chicagoland

2008 ML350 4matic

A/C compressor kicking on and off.....1200 rpm seems high tho....

Jun 8, 2010 | 03:19 PM

Vernl

Member

Joined: Mar 2008

Posts: 207

Likes: 1

ML320CDI 2008 all options inc air suspension

Quote:

Originally Posted by 360º

You dont mention how many miles or when it was last serviced so its hard to do anything but guess...if it hasnt been serviced by a dealer in awhile it could be the air idle bypasses in the throttle body have a film built up around them throwing off the mixture at idle and causing sensors to compensate thus the up and down revs.....if you cant take it to the dealer...take off the air cleaner at the throttle body and use some throttle body spray cleaner to clean it out and wipe it off with a lint free rag....