HELP: Dealer can't diagnose - Bad Idle/Bucking at Light
MBWorld Fanatic!
Joined: Oct 2006
Posts: 3,642
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From: Caribbean/Florida/Colorado
E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
There are threads about bad injectors leaking and causing a backfire that can crack the intake manifold.
This is classic vacuum leak symptoms.
Senior Member
Joined: Jul 2006
Posts: 289
Likes: 4
From: Woodland Hills, CA
1999 e55 (past), 2002 CLK55 (past), 2004 E55 (present), 2008 Z06
To the OP:
I was experiencing the same problem described in your post. Random bucking/surging at idle, the car ran fine above 1000 rpms. I took the car to my mechanic and they could not replicate the problem. One month later, car was due for service and I had all the plugs and wires changed. Problem solved. Car now runs like new.
Good luck.
I was experiencing the same problem described in your post. Random bucking/surging at idle, the car ran fine above 1000 rpms. I took the car to my mechanic and they could not replicate the problem. One month later, car was due for service and I had all the plugs and wires changed. Problem solved. Car now runs like new.
Good luck.
Thread Starter
Banned
Joined: Dec 2004
Posts: 196
Likes: 11
Issue finally fixed...
After changes to ECM (they then had to put the old one back in at no charge because that was not the problem), plugs, Ignition cables... etc... which helped somewhat with the bad bucking at the light... final issue (missing/shudder while idling) was resolved by EGR valve.. replacement.
Technically the car was at the dealer from April 11th until May 4th!
Thanks to all... Just glad I have it back. My biggest dissapointment in the whole process was the dealer was in a hurry to discharge the car after bucking was fixed but the rough idle was not... I think I burnt some bridges there... Service Manager did jump in and save the day in the end.
This has been a nightmare...
After changes to ECM (they then had to put the old one back in at no charge because that was not the problem), plugs, Ignition cables... etc... which helped somewhat with the bad bucking at the light... final issue (missing/shudder while idling) was resolved by EGR valve.. replacement.
Technically the car was at the dealer from April 11th until May 4th!
Thanks to all... Just glad I have it back. My biggest dissapointment in the whole process was the dealer was in a hurry to discharge the car after bucking was fixed but the rough idle was not... I think I burnt some bridges there... Service Manager did jump in and save the day in the end.
This has been a nightmare...
Senior Member
Joined: Apr 2008
Posts: 274
Likes: 0
From: Oakland, CA
2011 C63
good to know, my indy mech, which had me replace every other part on the car, insists its not the egr valve...egr valve doesn't work that way...
hopefully this fixes my issue so i can throw the old egr valve in his face
hopefully this fixes my issue so i can throw the old egr valve in his face
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Joined: Jan 2010
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From: MICHIGAN
2001 E55 - 2008 CLS63 -2016 F-150
thats cool that you got it fixed .. aND got the car back !!!
Desired speeds , changed his out and it still does it .. not sure if i should pick one up or not now ..
Desired speeds , changed his out and it still does it .. not sure if i should pick one up or not now ..
Super Member
Joined: Sep 2010
Posts: 553
Likes: 3
From: Los Angeles
W210 E55
Congrats. Bad EGR valves are just like big vacuum leaks. A simple vacuum gauge on the manifold would have found it long ago. Unbelievable that the dealer could not find the problem sooner with the symptom manifesting constantly. What happened to good old know-how?
Too bad. I suggested the vacuum be checked back on May 2nd. Apparently they did not do this.
Too bad. I suggested the vacuum be checked back on May 2nd. Apparently they did not do this.
Last edited by Schweinhund; May 19, 2011 at 06:06 PM.
Senior Member
Joined: Feb 2011
Posts: 312
Likes: 8
From: South, FL
2002 E55 AMG Obsidian Black with Charcoal
To the OP: Glad that you got your car back, and it's repaired correctly (finally).
Last edited by cudaized; May 19, 2011 at 09:13 PM.
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Newbie
Joined: Apr 2011
Posts: 2
Likes: 0
e55
I had the same problem .they couldn't find any thing wrong so i decided to try fixing it my self with a bottle of mass air flow sensor cleaner it worked for me,i took it all the way off the car cleaned it and blew it out with a air hose,hope it works for you
Super Member
Joined: Nov 2004
Posts: 992
Likes: 11
From: Illinois
GL550, C55, 335i Coupe, vintage Mustang
There was an old(real old) technical bulletin regarding 2000 and 2001 E55s that would buck when coming to a stop. You basically have to two foot the car to keep it running. It will not throw codes, so you won't be getting a check engine light. If I remember correctly, it gives an affected ECU part number, and that the remedy is to replace the ECU.
Nick
Nick
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Joined: Dec 2008
Posts: 2,396
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From: Bay Area, CA
2007 SL55 AMG
you know what I found interesting? I was in my friend's CLS63 last time and it did the exact thing my car was doing. It had a funny idle when you started it up just like my car and when I was sitting at a stoplight the car had the same roughness to it. He also mentioned that his old E55 also had this slightly rough idle. I'm pretty convinced that my car is perfectly normal. Can anybody chime in to say their car also has a certain roughness to it? Or are your cars perfectly still when sitting at a stoplight what you cannot feel the engine at all?
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Joined: Apr 2011
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From: Central Connecticut
86 190D (Exported to the Nerderlands), 87 300TD (Sold), 82 Ford F150 3spd, 99 E300D (RIP), 02 E55
I think it is normal for the high performance V8s to do that. After driving for awhile, my car does a little rough idling when stop at a light. Sometimes I drive the car hard and the rough idling does not occur but at times it does. I never even though of anything about it as compare to my friend's E320 which is not as I kept thinking of my college days when a fraternity brother of mine had an old firebird and talk about rough idling 
now that thing is rough.
now that thing is rough.
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Joined: Feb 2008
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From: Bostonian Ma
2012 CLS63 AMG
Issue finally fixed...
After changes to ECM (they then had to put the old one back in at no charge because that was not the problem), plugs, Ignition cables... etc... which helped somewhat with the bad bucking at the light... final issue (missing/shudder while idling) was resolved by EGR valve.. replacement.
Technically the car was at the dealer from April 11th until May 4th!
Thanks to all... Just glad I have it back. My biggest dissapointment in the whole process was the dealer was in a hurry to discharge the car after bucking was fixed but the rough idle was not... I think I burnt some bridges there... Service Manager did jump in and save the day in the end.
This has been a nightmare...
After changes to ECM (they then had to put the old one back in at no charge because that was not the problem), plugs, Ignition cables... etc... which helped somewhat with the bad bucking at the light... final issue (missing/shudder while idling) was resolved by EGR valve.. replacement.
Technically the car was at the dealer from April 11th until May 4th!
Thanks to all... Just glad I have it back. My biggest dissapointment in the whole process was the dealer was in a hurry to discharge the car after bucking was fixed but the rough idle was not... I think I burnt some bridges there... Service Manager did jump in and save the day in the end.
This has been a nightmare...
EGR eh
Interesting indeed. You would think with all the high end data equipment they would have found the issue a lot sooner than later. However problem fixed!
Welcome back
Junior Member
Joined: Jul 2010
Posts: 53
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From: San Antonio, TX
2008 E63 AMG
you know what I found interesting? I was in my friend's CLS63 last time and it did the exact thing my car was doing. It had a funny idle when you started it up just like my car and when I was sitting at a stoplight the car had the same roughness to it. He also mentioned that his old E55 also had this slightly rough idle. I'm pretty convinced that my car is perfectly normal. Can anybody chime in to say their car also has a certain roughness to it? Or are your cars perfectly still when sitting at a stoplight what you cannot feel the engine at all?
Member
Joined: Aug 2011
Posts: 104
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From: Sothern California
2000 w210 E55
Today I found myself replacing wires, plugs and fuel filter. Thinking that that was responsible for the rough idle at the stop and hard time starting. Turns out my egr valve was stuck open causing six out of eight cylinders to misfire, causing the rough idle. Im so glad to have my baby running good again.
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From: Bay Area, CA
2007 SL55 AMG
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From: Los Angeles
W210 E55
Member
Joined: Jun 2007
Posts: 202
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From: University Place, WA
2000 W210 E55// 2007 Toyota Tacoma X-Runner
Mine started stumbling at 3K RPM, no CEL, it turned out to be a bad spark plug wire. Replaced with magnecore wires in 2008 been happy ever since.
