Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-23-2018, 10:28 PM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
1995 W124 Wagon - Surge Issue

Hi folks,

From stop, slowly accelerating, the wagon RPMs suddenly surges when it reaches 2K-2.5K RPM marks when cold or warm. When the car gets hot, I have no surging issues even starting from a stop position. Any ideas what maybe causing this surge? Could it be a transmission shifting issue? Any assistance is greatly appreciated. Thanks!

__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI
Reply With Quote
  #2  
Old 09-23-2018, 11:20 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,023
Does the vehicle change speed with the surge in engine RPM? If not, the transmission is slipping.
Reply With Quote
  #3  
Old 09-23-2018, 11:35 PM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
The wagon still accelerates in a constant pace when it surges. Could it be the modulator valve?
__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI

Last edited by cleavster; 09-23-2018 at 11:45 PM.
Reply With Quote
  #4  
Old 09-23-2018, 11:57 PM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,023
The modulator affects shifting firmness. Slipping while in gear is due to wear, problems in the valve body, incorrect fluid level or type, or a worn pump causing low operating pressure.

Check the fluid level before getting carried away. If it's been >30K miles since the last transmission oil and filter change, the time is well past and could be a contributing factor.
Reply With Quote
  #5  
Old 09-24-2018, 01:33 AM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
I'll check tomorrow morning. There are some leaks on the ground and after close examination it looks like ATF, red in color.
__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI
Reply With Quote
  #6  
Old 09-24-2018, 06:23 AM
Registered User
 
Join Date: Feb 2008
Location: Madeira Beach, FL
Posts: 57
Have the throttle actuator and upper harness been changed out with post 1998 replacements? When were the coils and plugs last changed?

Sent from my XT1710-02 using Tapatalk
Reply With Quote
  #7  
Old 09-24-2018, 09:19 AM
Diseasel300's Avatar
Registered User
 
Join Date: May 2016
Posts: 6,023
Quote:
Originally Posted by Jayare View Post
Have the throttle actuator and upper harness been changed out with post 1998 replacements? When were the coils and plugs last changed?
Those issues should be addressed, but they're not the problem here. If they were, the car would be lurching forward as if under firm acceleration when the engine RPM spikes.
Reply With Quote
  #8  
Old 09-24-2018, 09:21 AM
Registered User
 
Join Date: Feb 2008
Location: Madeira Beach, FL
Posts: 57
Good luck

Sent from my XT1710-02 using Tapatalk
Reply With Quote
  #9  
Old 09-26-2018, 03:57 PM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
I tried measuring the transmission fluid using this procedure:

Started the car
Warm up for 20 minutes
Shifted the car through its gears
Pulled out the dipstick and wipe off using a lint free rag
Push back for 5 seconds
Pulled out to measure and I could not tell if there was any fluid being measured.

I did this many times and still cannot tell for sure. Now, when the car was cold this morning, I pulled out the dipstick and there was fluid in the dipstick. Is there something I should be doing? Is there another procedure I need to know to properly measure?
__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI
Reply With Quote
  #10  
Old 09-26-2018, 04:24 PM
Registered User
 
Join Date: Feb 2008
Location: Madeira Beach, FL
Posts: 57
Transmission fluid will "fill" into the pan as the unit cools. The primary reason for "fully warmed", running in park on a flat surface. Drive the car for 20+ minutes, a couple of traffic lights etc to get it warmed up.

You'll notice a series of small notches on the bottom of the stick. Look for fluid to be in one of them. Best if it was in the middle.

Jayare

Sent from my XT1710-02 using Tapatalk
Reply With Quote
  #11  
Old 10-12-2018, 11:14 AM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
Got it! The ATF fluid was low and once filled, the surging stopped. Whew!

However, There is a prominent leak coming from the modulator valve. I ordered a replacement part and should be arriving today so I can work on it this weekend.

From what I gathered, this is a remove and replace procedure and fine tuning involved if need be. Before removing the part, do I have to drain the fluid? Thanks.
__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI

Last edited by cleavster; 10-12-2018 at 07:35 PM.
Reply With Quote
  #12  
Old 10-14-2018, 01:02 AM
dieseldiehard's Avatar
Dieseldiehard
 
Join Date: Oct 2002
Location: Bay Area No Calif.
Posts: 4,340
Quote:
Originally Posted by cleavster View Post
Got it! The ATF fluid was low and once filled, the surging stopped. Whew!

However, There is a prominent leak coming from the modulator valve. I ordered a replacement part and should be arriving today so I can work on it this weekend.

From what I gathered, this is a remove and replace procedure and fine tuning involved if need be. Before removing the part, do I have to drain the fluid? Thanks.
Hi, neighbor! are you the owner of a smoked silver 95 wagon like mine parked occasionally near W 3rd ave? I guess we should meet up sometime.

You don't have any problem removing the modulator valve as its above the pan.
FWIW I just sent my '95 wagon to have its tranny rebuilt, it started shifting oddly, hard clunks as it nears a stop then started slipping under power. And the rear main seal leaking so need to pull the trans to get to the back end of the motor so may as well.
The consensus of the folks at MZF aka Peter Schmid transmission shop in Burlingame was it is due a rebuild (not doing the work there however). Oh dear, its going to cost me more than I paid for the entire car 3 years ago, at only 150K miles its sad to have to invest in a transmission job but I drive the car a lot and its in good condition....
I hope yours is not in the same category..
DDH
__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!
Reply With Quote
  #13  
Old 10-21-2018, 07:40 PM
Registered User
 
Join Date: May 2008
Location: San Mateo, CA
Posts: 102
Thank you for the info. The modulator has been replaced and the rubber gasket is very brittle and just replaced the whole unit.

Unfortunately, I have one more leak coming from the same area. The leak is coming from harness that is plugged into the transmission to the left of the modulator.

Does anyone know hot remedy this problem?

Dieseldiehard - when you get a chance, PM me and like to meet peeps with the same wagon.

__________________
---------------------
200 75 W115 (Mom's)
190e 90 2.6 W201
E320 95 Wagon W124
72 BMW 3.0 CSI

Last edited by cleavster; 10-22-2018 at 05:06 PM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 11:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page