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#1
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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!
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--------------------- 200 75 W115 (Mom's) 190e 90 2.6 W201 E320 95 Wagon W124 72 BMW 3.0 CSI |
#2
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Does the vehicle change speed with the surge in engine RPM? If not, the transmission is slipping.
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Current stable: 1995 E320 157K (Nancy) 1983 500SL 125K (SLoL) Gone but not forgotten: 1986 300SDL (RIP) 1991 350SD 1991 560SEL 1990 560SEL 1986 500SEL Euro (Rusted to nothing at 47K!) Gone and wanting to forget: 1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz] |
#3
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The wagon still accelerates in a constant pace when it surges. Could it be the modulator valve?
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--------------------- 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. |
#4
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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.
__________________
Current stable: 1995 E320 157K (Nancy) 1983 500SL 125K (SLoL) Gone but not forgotten: 1986 300SDL (RIP) 1991 350SD 1991 560SEL 1990 560SEL 1986 500SEL Euro (Rusted to nothing at 47K!) Gone and wanting to forget: 1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz] |
#5
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I'll check tomorrow morning. There are some leaks on the ground and after close examination it looks like ATF, red in color.
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--------------------- 200 75 W115 (Mom's) 190e 90 2.6 W201 E320 95 Wagon W124 72 BMW 3.0 CSI |
#6
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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 |
#7
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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.
__________________
Current stable: 1995 E320 157K (Nancy) 1983 500SL 125K (SLoL) Gone but not forgotten: 1986 300SDL (RIP) 1991 350SD 1991 560SEL 1990 560SEL 1986 500SEL Euro (Rusted to nothing at 47K!) Gone and wanting to forget: 1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz] |
#8
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Good luck
Sent from my XT1710-02 using Tapatalk |
#9
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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?
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--------------------- 200 75 W115 (Mom's) 190e 90 2.6 W201 E320 95 Wagon W124 72 BMW 3.0 CSI |
#10
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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 |
#11
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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.
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--------------------- 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. |
#12
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Quote:
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
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'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! |
#13
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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.
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--------------------- 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. |
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