torque converter lockup...shameless crosspost
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From: USA
Marsaydees
torque converter lockup...shameless crosspost
https://mbworld.org/forums/c-class-w...-question.html
sooo, what next?
ECU tune from eurocharged? high stall torque converter? rocket launcher?
sooo, what next?
ECU tune from eurocharged? high stall torque converter? rocket launcher?
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2005 Pontiac GTO 6.0 LS2 - Blue
I'm in the same situation where the transmission will jerk after letting off the throttle in 2nd gear, and applying throttle... I assumed this was the normal torque converter jerk that most people get in their C32's.
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Marsaydees
maybe there are people in both camps...
did you see my videos i posted of the jerk?
i decided to take a video, forgive the crappy iphone footage...
forgive the CEL, freaking worthless secondary air pump...
video 1: demonstrates the problem, at constant throttle, no problem. i let off the throttle, you see the rpm's drop, then i get back on the throttle and it jerks back down to 1700rpm
http://www.youtube.com/watch?v=OOVcqo1ZeJc
video 2: after some WOT passes, the converter stays locked on decel, as it should. this is absurd that i have to smash the gas pedal to avoid this crap
http://www.youtube.com/watch?v=-LZnzouXa5g
forgive the CEL, freaking worthless secondary air pump...
video 1: demonstrates the problem, at constant throttle, no problem. i let off the throttle, you see the rpm's drop, then i get back on the throttle and it jerks back down to 1700rpm
http://www.youtube.com/watch?v=OOVcqo1ZeJc
video 2: after some WOT passes, the converter stays locked on decel, as it should. this is absurd that i have to smash the gas pedal to avoid this crap
http://www.youtube.com/watch?v=-LZnzouXa5g
Thread Starter
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Marsaydees
the thing is, its definitely in the software because you can bypass the lockup event at 2000rpm by giving it 50-60% throttle. the rpm's just go right to about 2400 and the car accelerates for a few hundred rpm's and then shifts smoothly into the next gear.
i guess i'll have to take a video to be more clear
i guess i'll have to take a video to be more clear
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From: Indiana
Silver 02 C32 & White 05 CLK500
I am having the same problem where I go through first and get to second gear in S mode, then let off the gas, then get back on and the car jerks, somewhat looses power, and then gets back on it. I am also experiencing the 1500 rpm jerk in W mode and a slight jerk in the middle of 2 gear in S mode when normal driving. I have had the transmission, tcu, radiator, torque converter and other little things replaced under warranty. I was guessing that that is the nature of the car to be jerky. On second note, I owned a 01 C320 and the ride quality was MUCH better than the C32 and was a MUCH smoother. My c320 never jerked in any way. It was always smooth and power was on tap. The C32 however, gives me nothing but problems. Now I am having slow acceleration issues which I think that my TPS sensor is causing and I have to get a new accelerator pedal. Our issue has probably something to do with the torque converter unlocking because once you let off the gas, it feels like it should unlock because the car is not accelerating any more in second gear, and when you get on it again, it jerks. I am also thinking it is a software issue and nothing serious, but annoying as hell. Please keep us updated, and I hope you solve the problem
.
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From: Houston, TX
C32/C55 AMG
I have the same problem as you. I get a hard clunk when I'm doing a slow acceleration and I've noticed it even after longer drives.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
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Marsaydees
I have the same problem as you. I get a hard clunk when I'm doing a slow acceleration and I've noticed it even after longer drives.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
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Joined: May 2008
Posts: 340
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From: Indiana
Silver 02 C32 & White 05 CLK500
I have the same problem as you. I get a hard clunk when I'm doing a slow acceleration and I've noticed it even after longer drives.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
The car seems to respond normal under heavy acceleration, but I've even had the clunk issue when getting on it hard. The only way I can explain it is that the car will speed up and then seem to decelerate and then catch and continue to speed up. I haven't had it happen a lot, but I've noticed it.
I feel like my transmission holds back my acceleration, but I think that's another thread.
http://www.mercedesforum.com/forum/s...ad.php?t=36789
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From: Indiana
Silver 02 C32 & White 05 CLK500
https://mbworld.org/forums/c32-amg-c...-c32-tsbs.html
I took my car to the mercedes dealer and explained my problem and also gave them that info about the torque converter adaptation. They told me that they can do that process, but will take around 2 hours. One service representative told me that it is dangerous for me to get procedures of the internet quote "Be careful what you get off the internet, by the way, how on earth did you get that?" He did not like the idea that people are actually doing research and trying to fix the problems themselves rather than going to the dealership lol. So, I figured 2 hours *$130 per hour would equal $260. For one, I am not quite certain if it will fix the problem, or I will just throw away $260 in this tough economy on a problem that even when "fixed", might still come back to haunt me much like the 1500 rpm jerk that came back after new transmission, radiator, and the torque converter.
Last edited by alkrstev; Mar 5, 2010 at 03:17 AM.
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From: Orlando FL
CLK55 AMG
i get the jerk at a slow acceleration. not so much when applied 60-100% trottle. from all the other threads this looks as to be the gykol? im not to sure but for everyone else's experiance this seems to be the problem
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From: Orlando FL
CLK55 AMG
I am having the same problem where I go through first and get to second gear in S mode, then let off the gas, then get back on and the car jerks, somewhat looses power, and then gets back on it. I am also experiencing the 1500 rpm jerk in W mode and a slight jerk in the middle of 2 gear in S mode when normal driving. I have had the transmission, tcu, radiator, torque converter and other little things replaced under warranty. I was guessing that that is the nature of the car to be jerky. On second note, I owned a 01 C320 and the ride quality was MUCH better than the C32 and was a MUCH smoother. My c320 never jerked in any way. It was always smooth and power was on tap. The C32 however, gives me nothing but problems. Now I am having slow acceleration issues which I think that my TPS sensor is causing and I have to get a new accelerator pedal. Our issue has probably something to do with the torque converter unlocking because once you let off the gas, it feels like it should unlock because the car is not accelerating any more in second gear, and when you get on it again, it jerks. I am also thinking it is a software issue and nothing serious, but annoying as hell. Please keep us updated, and I hope you solve the problem.
.without the other stuff about the c320 and getting the parts replaced
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From: Indiana
Silver 02 C32 & White 05 CLK500
There is no way that my car has glycol contamination. All my parts that include the transmission, radiator, a torque converter, and a tcu are around 13k old. I am still leaning towards it not being a transmission problem, but rather a TPS problem, and will be ordering a brand new gas pedal assembly from parts.com soon. It could also be an inadequate adaptation of the torque converter to each gear.
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Marsaydees
There is no way that my car has glycol contamination. All my parts that include the transmission, radiator, a torque converter, and a tcu are around 13k old. I am still leaning towards it not being a transmission problem, but rather a TPS problem, and will be ordering a brand new gas pedal assembly from parts.com soon. It could also be an inadequate adaptation of the torque converter to each gear.
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
Blamestorming here... any chance this has to do with the S/C engagement-disengagement process? Seems that the TC would "see" drastically different torque levels, depending on if the S/C is engaged or not... accellerating might engage the S/C, then backing off throttle and load disengages, TCU/TC gets confused about when to lock up or not, causing some of the jerks/clunks issues reported by owners.
Any merit to the above scenario?
Any merit to the above scenario?
Senior Member
Joined: May 2008
Posts: 340
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From: Indiana
Silver 02 C32 & White 05 CLK500
Blamestorming here... any chance this has to do with the S/C engagement-disengagement process? Seems that the TC would "see" drastically different torque levels, depending on if the S/C is engaged or not... accellerating might engage the S/C, then backing off throttle and load disengages, TCU/TC gets confused about when to lock up or not, causing some of the jerks/clunks issues reported by owners.
Any merit to the above scenario?
Any merit to the above scenario?
Senior Member
Joined: May 2008
Posts: 340
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From: Indiana
Silver 02 C32 & White 05 CLK500
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From: NY
'03C32 Obsidian Black, '76Toyota Celica GT TRD, '12R350 4matic Arctic White, '06 ML 350 arctic white
just saw your post and vid on the trans. clunk thingy... had the same problem just like your vid but in addition, happened only on one occasion when merging, the car shifted into neutral by itself. so, i recently had a trans fluid flush and filter replacement as well as a trans, software flash and that seemed to solve the problem so far. I have about 45k on the odo. hope this helps and GL.
John
John
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2005 Pontiac GTO 6.0 LS2 - Blue
Rough engagement followed by droning or buzzing sound is listed as either glycol contamination, or EGS ECU adaptation problem. Says to have all adaptation codes cleared as a first step, and then perform glycol test if problem is still present.
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Marsaydees
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
The EGS is also sometimes referred to as the "TCU" and controls transmission functions. It's a box (Siemens, IIRC) in the passenger-side footwell.
Since the TCU "learns" driving behavior and attempts to adapt shift patterns and activity to it, clearing the adaptions wipes out that memory and can potentially fix a misbehaving gearbox. Any reputable shop with Star should be able to clear those adaptions for you, I believe.
Since the TCU "learns" driving behavior and attempts to adapt shift patterns and activity to it, clearing the adaptions wipes out that memory and can potentially fix a misbehaving gearbox. Any reputable shop with Star should be able to clear those adaptions for you, I believe.
