Torque Converter Issue?

[hybridsix]

Hey guys,

My car over the last few months has developed an odd problem. When I'm slowing down for a stop, the car will slow down, bog for a second(under 5 mph), and then lurch forward a bit. If I stop quickly , the problem doesn't seem to appear. Also, if I am going to stop slowly, and brake, then let off, then brake again, it also doesn't happen. I'd like to say that I notice it more after a lot of city driving, but, that could just be because I'm physically stopping more.

My guess is that the torque converter isn't unlocking, and the car is shifting into first, which is causing the lurching effect, from the added torque. Has anyone else had this issue? Could it be just a brake switch that's sticky, and not allowing the TCC to unlock?

Also, No CEL, and no codes that OnStar can read anyway.

Any help or direction to go in would be much appreciated. Power train is still under factory warranty, so eventually it'll go back to the dealer, especially if its something major.

G6 GXP with the 6 Speed Auto

[BobcatG6]

Re: Torque Converter Issue?

Might be a vacuum issue with the brake booster, however I'm not entirely sure.

[black07g6gtp]

Re: Torque Converter Issue?

My car does the same thing!!! Do you notice when you're coasting in traffic and you put your foot back on the gas it reengages hard?

[Johnny 6]

Re: Torque Converter Issue?

My car does the same thing!!! Do you notice when you're coasting in traffic and you put your foot back on the gas it reengages hard?

I've noticed this on mine as well. Usually if I roll a stop sign, it downshifts and kicks back into 1st hard! I was thinking it is the load being transferred to the motor. I could be totally off base but I was going to try some MMI motor mounts along with the WAMS TCM tune too see if it helps.

[BL07GTP]

Re: Torque Converter Issue?

My car does the same thing!!! Do you notice when you're coasting in traffic and you put your foot back on the gas it reengages hard?

same here i think its just how it shifts. and i can get it to do it even when its not shifting

[BL07GTP]

Re: Torque Converter Issue?

My car does the same thing!!! Do you notice when you're coasting in traffic and you put your foot back on the gas it reengages hard?

do u think its bad for it to do that? it seems like its when the motor supplies torque to the tranny

[SmartGTP]

Re: Torque Converter Issue?

could be line pressure?

[hybridsix]

Re: Torque Converter Issue?

It would be cool if someone with a data logger for the motor and trans could take a snapshot of the data during that time while the car is doing it. Might give us more insight. (Any takers?)

In an attempt to fix or postpone the problem, I pulled the TCM fuse and left it out for awhile(about 10 min), hoping to let the transmission computer re-learn again. So far, I have not had the issue again yet. But, we shall see over the next week. Guess its time to do some more city driving.

[BL07GTP]

Re: Torque Converter Issue?

It would be cool if someone with a data logger for the motor and trans could take a snapshot of the data during that time while the car is doing it. Might give us more insight. (Any takers?)

In an attempt to fix or postpone the problem, I pulled the TCM fuse and left it out for awhile(about 10 min), hoping to let the transmission computer re-learn again. So far, I have not had the issue again yet. But, we shall see over the next week. Guess its time to do some more city driving.

i got nothing on the data logger. keep us updated

[BL07GTP]

Re: Torque Converter Issue?

My car does the same thing!!! Do you notice when you're coasting in traffic and you put your foot back on the gas it reengages hard?

ive kinda notice that with my car. do you think thats normal for the hydromatic tranny?

[SexyG6]

Re: Torque Converter Issue?

I've noticed this on mine as well. Usually if I roll a stop sign, it downshifts and kicks back into 1st hard! I was thinking it is the load being transferred to the motor. I could be totally off base but I was going to try some MMI motor mounts along with the WAMS TCM tune too see if it helps.

as far as THIS goes thats cuz the trans does NOT shift into first when your coming to a stop until you are at a dead stop, of course its gonna shift hard to first when you give it a lot of gas from an almost stop, because its not in first already

[Neatong6er]

Re: Torque Converter Issue?

as far as THIS goes thats cuz the trans does NOT shift into first when your coming to a stop until you are at a dead stop, of course its gonna shift hard to first when you give it a lot of gas from an almost stop, because its not in first already

THIS. If you have a manual mode put it there and watch it. It will automatically downshift for you if you haven't noticed and if you leave it in 2nd and come to a stop you will notice that it doesn't hit first until almost a dead stop. Therefore when you do a rolling stop and then get in it the transmission will kick down to first to make handle the power the motor is giving it causing the jerk. I wouldn't say it's bad, but it's not good.