M-Class (W163) Produced 1998-2005: ML 230, ML 320, ML 350, ML 400 CDI, ML 430, ML 500, ML 270 CDI

Restoring Idle Speed to normal

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Feb 21, 2022 | 05:04 PM
  #1  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Restoring Idle Speed to normal

I have a 2001 ML 320 99k miles and my idle has been going down between 500-600 (the tach sits right on top of the 500 line) when the car is on drive and the car starts to shudder when I’m at the stop light. If I put the car on N or P the idle goes up to 800 and the shudder goes away. I have replaced the spark plugs and wires, MAF, and CPS sensor. The shudder gets worst at the stop light if I turn the AC on or when the fan turns on. Does anyone know how to adjust the idle?
Reply
Old Feb 22, 2022 | 04:07 AM
  #2  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
You should check for codes in the ECM. You could have a prob. with B37.


Attached Thumbnails Restoring Idle Speed to normal-b37-loc..jpg  
Attached Files
File Type: pdf
DTC ECM.pdf (313.9 KB, 129 views)
Reply
Old Feb 22, 2022 | 11:06 AM
  #3  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Do you know what is the normal idle speed should be when the car is on D? Thanks Dundee
Reply
Old Feb 22, 2022 | 02:30 PM
  #4  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Originally Posted by jay4usc
Do you know what is the normal idle speed should be when the car is on D? Thanks Dundee
M/B does not supply that info, that I know of.

You ask when it is in Drive but that will take starting a cold eng. and putting in D. And the other one would be after the eng. is at operating Temp.
Reply
Old Feb 22, 2022 | 02:57 PM
  #5  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Originally Posted by Maj. Dundee
M/B does not supply that info, that I know of.

You ask when it is in Drive but that will take starting a cold eng. and putting in D. And the other one would be after the eng. is at operating Temp.

when the engine is warm. I have no issues when engine is cold where the rpm is at 800. When it’s warm it drops to 550 and that’s when I get the shudder. I’m wondering if 550 is normal.
Reply
Old Feb 22, 2022 | 06:12 PM
  #6  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
I will check on car the next time I go out.
Reply
Old Feb 23, 2022 | 05:36 AM
  #7  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Could you please scan for codes.

Try this automatic relearn.


Last edited by Maj. Dundee; Feb 23, 2022 at 06:18 AM.
Reply
Old Feb 23, 2022 | 10:10 AM
  #8  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Originally Posted by Maj. Dundee
Could you please scan for codes.

Try this automatic relearn.

https://www.youtube.com/watch?v=abHDRl8miRo
i have no codes and I already perform that reset. Thanks Dundee
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
Old Feb 23, 2022 | 11:28 AM
  #9  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
did it work?
Reply
Old Feb 23, 2022 | 11:34 AM
  #10  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Originally Posted by Maj. Dundee
did it work?

No. My normal idle speed when in D is still at 550 rpm (warm engine) and my car still shudders at the stop light especially first 3 miles.

I’m going to the mechanic today have the motor and transmission mounts checked.
Reply
Old Feb 24, 2022 | 09:49 PM
  #11  
jay4usc's Avatar
Thread Starter
Member
5 Year Member
 
Joined: Oct 2018
Posts: 76
Likes: 13
From: Lakewood, Ca
2001 ML 320
Originally Posted by Maj. Dundee
did it work?

hey Dundee it was the motor mount causing all the shuddering. The mechanic said they are not worn out but rather got hardened and showed my the comparison with the brand new mounts which were softer.

thanks for your help
Reply
Old Mar 6, 2022 | 09:01 AM
  #12  
Maj. Dundee's Avatar
MBWorld Fanatic!
 
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Great info & glad your problem is over.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 01:32 PM.

story-0
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-1
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-2
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-3
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-4
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-5
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-6
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-7
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-8
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-9
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE