Rough Idle! please help
Thread Starter
Super Member
Joined: Sep 2006
Posts: 563
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From: California
1998 E320
Rough Idle! please help
My car has a slightly rough idle when in drive. If it is in park, there is no problem. If I hold the brake, and lightly gas it, it becomes smooth again.
I searched throughout the forums and found the causes of my problem to be either Motor mounts, MAF,Spark plugs, or Harmonic balancer. I have replaced my MAF about 3 months ago, so I hope it is not that. I don't think it is the motor mounts because wouldn't that cause vibrations at all speeds? And I know nothing about the harmonic balancer. PLEASE, any help would be appreciated.
I searched throughout the forums and found the causes of my problem to be either Motor mounts, MAF,Spark plugs, or Harmonic balancer. I have replaced my MAF about 3 months ago, so I hope it is not that. I don't think it is the motor mounts because wouldn't that cause vibrations at all speeds? And I know nothing about the harmonic balancer. PLEASE, any help would be appreciated.
Last edited by OldNate; May 22, 2007 at 08:42 PM.
Member
Joined: Sep 2006
Posts: 237
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From: Los Angeles, CA
G63 W463
i dont know if ur the first owner or not so try this...
the harmonic balancer recall has to be done DEPENDING on your vehicle year
if ur not the first owner and have not had it replaced call ur local dealer and theyll run your vin and tell you if its been done or not. Regardless if thats the problem... you should call and see if its been done.
Its free....couldnt hurt
that may solve ur problem....
because bad blugs could cause misfire...as well as bad coils
if uve cleaned ur MAF already, that wouldve been the problem but in ur case it shouldnt be
hope this helped.
the harmonic balancer recall has to be done DEPENDING on your vehicle year
if ur not the first owner and have not had it replaced call ur local dealer and theyll run your vin and tell you if its been done or not. Regardless if thats the problem... you should call and see if its been done.
Its free....couldnt hurt
that may solve ur problem....
because bad blugs could cause misfire...as well as bad coils
if uve cleaned ur MAF already, that wouldve been the problem but in ur case it shouldnt be
hope this helped.
Thread Starter
Super Member
Joined: Sep 2006
Posts: 563
Likes: 0
From: California
1998 E320
i'll give the dealer a call right now. I don't want to go replacing things that don't need to be replaced. For example, TG, I think it was probably either the 02 sensor, or the maf, but not both. Did you fix them at the same time?
Also, Wouldn't the harmonic balancer cause the car to be rough at all times (not just idle)?
Also, Wouldn't the harmonic balancer cause the car to be rough at all times (not just idle)?
Last edited by OldNate; May 22, 2007 at 10:19 PM.
Senior Member
Joined: Apr 2006
Posts: 271
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From: Cranston, Rhode Island
01' E Fifty Five
Nate, let me know what happened when you talked to the dealer. I got the same issue. Mines a 2000 E320, its rough in drive and not park....all the same things you described. The strange thing with mine is it doesnt happen all the time. It may be rough one day and smooth another. Let me know
Member
Joined: Sep 2006
Posts: 237
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From: Los Angeles, CA
G63 W463
Nate, let me know what happened when you talked to the dealer. I got the same issue. Mines a 2000 E320, its rough in drive and not park....all the same things you described. The strange thing with mine is it doesnt happen all the time. It may be rough one day and smooth another. Let me know
ur problem sounds like a mix of good/bad fuel....
next time u need to fill, use the highest grade available and see if theres any difference.
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On the harmonic balancer - I think that's a catastrophic failure - as when it goes bad, shiat comes flying apart. At least it did in my 98 E320 (@99K)before the recall was official. Took out the front timing chain cover, over $2K worth of damage after shutting the engine down immediately. Never knew it was coming until it happened. MBZ covered it thanks to knowing about it from this board and throwing it in their faces (besides, how do you maintain a harmonic balancer?)
If you are getting a vibration and hum - motor mounts. Have somebody gas your motor with the hood up - if your motor jumps, it's the mounts.
Mine went out, same symptoms. $400 stealership fix - others have changed them about, but no thanks, I still don't know anybody can get a factory spec/torque on some of the bolts which need to come off.
If you are getting a vibration and hum - motor mounts. Have somebody gas your motor with the hood up - if your motor jumps, it's the mounts.
Mine went out, same symptoms. $400 stealership fix - others have changed them about, but no thanks, I still don't know anybody can get a factory spec/torque on some of the bolts which need to come off.
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Member
Joined: Sep 2005
Posts: 187
Likes: 1
From: Fremont, CA
1998 E320 / 1992 LandCruiser / Project Car E30, 91, 318I
i just replaced my motor/engine mounts about 2 months ago. cas is smooth 
it all started with little vibration when in gear then gets worse
over a period of time (months) ... in gear, in park, in neutral vibration all
over but never when the car is moving.
good luck.
it all started with little vibration when in gear then gets worse
over a period of time (months) ... in gear, in park, in neutral vibration all
over but never when the car is moving.
good luck.
Last edited by 4XFORE; May 23, 2007 at 04:21 PM.
Member
Joined: Nov 2005
Posts: 212
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From: The Valley of the Sun
2000 E320, 2007 Land Rover LR3 HSE, 2008 E350
I had a similar problem two months ago - I learned to find out it was both my motor and tranny mounts collapsed/broke - my starmark warranty replaced both for free and now my vehicle rides very smooth. Assuming it was not the harmonic balancer, then possibly broken mounts.
