Idle Surge Issue
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Newbie
Joined: Dec 2004
Posts: 6
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Idle Surge Issue
Searched & searched and haven't really found a definative answer to my specific issue so, here goes...
My '94 E320 Cabriolet has an idle surging problem; not a huge surge but enough to be obnoxious. When the car is in gear at an idle, the RPM will jump from 550 to about 750 for a moment or two. This also seems to happen in reverse. Can't say for sure that anything else is wrong but I think my shifting might be a tad rougher than it had been.
Have seen a lot of references to vacuumn leaks, to Idle Control Valves, to MAFs, etc. etc. in the persuit of fixing a rough idle. How do I narrow down the hunt?
The idle surge doesn't happen all the time, it's intermittent. But it happens way too often to ignore it. Happens more-so when the car is cold (from sitting overnight in the garage). A mechanic said "It must be the Idle Control Module"; that's funny... is there such a thing on a '94 E320 Cabriolet? BTW, new motor mounts about 3k ago.
Gimme any ideas guys!
Thanks in advance
My '94 E320 Cabriolet has an idle surging problem; not a huge surge but enough to be obnoxious. When the car is in gear at an idle, the RPM will jump from 550 to about 750 for a moment or two. This also seems to happen in reverse. Can't say for sure that anything else is wrong but I think my shifting might be a tad rougher than it had been.
Have seen a lot of references to vacuumn leaks, to Idle Control Valves, to MAFs, etc. etc. in the persuit of fixing a rough idle. How do I narrow down the hunt?
The idle surge doesn't happen all the time, it's intermittent. But it happens way too often to ignore it. Happens more-so when the car is cold (from sitting overnight in the garage). A mechanic said "It must be the Idle Control Module"; that's funny... is there such a thing on a '94 E320 Cabriolet? BTW, new motor mounts about 3k ago.
Gimme any ideas guys!
Thanks in advance
Newbie
Joined: Jan 2005
Posts: 3
Likes: 0
From: Somerset, England
W124 E320 Cabriolet Sportline
Engine surge
My E220 W124 suffered this problem some time ago. For me, my engine was revving at 3000 whilst I tried to manouvre in a crowded car park.
I took the car to an independant mercedes garage where a mechanic removed the air filter and buried himself with cleaning agent and rag in the area fed by the filter.
Twenty minutes or so he asked me to start the car, then he adjusted the throttle linkeage.
Result: the car behaved itself until I sold it a few months later. The mechanic stated that the fuel that I was buying from supermarkets was not the cleanest and that I should in future, stick to proprietary brands.
Hope that this is of some help.
I took the car to an independant mercedes garage where a mechanic removed the air filter and buried himself with cleaning agent and rag in the area fed by the filter.
Twenty minutes or so he asked me to start the car, then he adjusted the throttle linkeage.
Result: the car behaved itself until I sold it a few months later. The mechanic stated that the fuel that I was buying from supermarkets was not the cleanest and that I should in future, stick to proprietary brands.
Hope that this is of some help.
