engine idle not stable and car shaking around.. ???
11-04-2006, 10:17 AM
#1
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engine idle not stable and car shaking around.. ???
my 97 E420 runs great, and I'm getting 24MPG on the highway @ 80MPH. However when the car is sitting at idle, the car is unstable, shakes around and the rpm would bounce around. any idea what might be wrong?? again the car is running great when moving.. 
11-19-2006, 11:32 PM
#2
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Sounds like the engine idle air sensor which after time can develop flat spots on the cam at the "speed" position. This then prevents it from returning to the "idle position", thus the engine is receiving the wrong air/fuel mixture.
11-20-2006, 02:38 AM
#3
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'92 R129 300SL-24, '01 W210 E240, '03 W220 S320, '02 745Li
The shaking I got at idle was a very constant yet random shake with no discernable pattern. Watching the wing mirrors, it looked like the car had an inch worth of travel shaking up and down.
My mechanic took one look in the engine bay, replaced the belt and one of the pulleys, the one right at the bottom, and it was sorted out.
My mechanic took one look in the engine bay, replaced the belt and one of the pulleys, the one right at the bottom, and it was sorted out.
