You guys have been helping me on my other problem…. the UIM ( Upper Intake Manifold) issue.

I’m a NEWBIE. I have cruised through a bunch of the threads relating to the Torque Converter Clutch. You guys do have lots of info on your forum and I’m doing my best to go through a lot of it….. But for me, sometimes it’* almost like I get information-overload…..

I have a non-supercharged 3.8L 1997 Bonneville with an auto. Mileage is 158 K miles.
I did have some transmission work done on this about 30 K miles ago…. Ever since then, I really haven’t been very happy with the performance of this tranny.

Here’* the problem:

Once the car has warmed-up to the point where the computer will try to engage the TCC, I am getting this funky problem…. If I had to guess…. this is what happens… when it’* in 3rd or 4th gear.:

Assume the TCC is engaged.
I step on the accelerator which imposes more torque to the TCC…. Like going up a hill.
The torque converter clutch starts to slip…. the computer senses the slip and increase the pressure to apply more pressure to the TCC. The TCC stops slipping and the computer senses that the slipping issue has been resolved… Now the “increased” pressure to the TCC goes away and the cycle starts over where the TCC slips…..
This cycle will occur about every 2-3 seconds.

Am I on drugs or what ?

Thanks,

Jack

It sounds like he'* dealing with the 'surge' or 'chuggle' that is common around here. Would you describe the car as 'surging' every 2-3 seconds when the cycle is occurring? I'll try to dig up a couple posts that explain the answer clearly. To sum it up, it is a heat-related problem that is caused by a worn valve body in the tranny. When the fluid has heated up to its operating temp and viscosity, it is not able to be properly restricted by this valve body, causing a surge or chuggle that is most noticeable when under load with the TCC locked.

Not sure what year you are, but I think this should apply regardless. It'* the actual GM service bulletin for this condition.

http://www.bonnevilleclub.com/forum/...ic.php?t=38917

I went out and dug out the repair slip. Here are the actuals:

1.) Transmission work done... Date: 8/12/2002 Mileage 105541
- Replace Torque Converter $180
-Replace Valve Body $567
-Gasket Set $44
-Filter $18
-10qts ATF Fluid $22
Labor $432

The reason we took it in to a transmission repair shop was because we were getting an "Error" code ... I don't actually remember the code number... something like 1437... 1847... something like that and I remember it meant "Ratio error" which indicated that the TCC was slipping.... I was told that by a transmission mechanic at a Pontiac garage.

The car now has 158.5 K miles on it. Although at this point I think it slips a lot,.... the computer never spits-out that code anymore.

You guys are awesome ! Yes this does sound like that is going on with my transmission.

This problem has been going on for a while now. I fear damage my now have been done to the Torque Converter. If this "slip" occurs when you have the windows down and there is something along side the road, like a guardrail or embackment to reflect the sound back to the driver, then you can hear an almost "scraping" noise coming from underneath the car during this "slipping" event.

I'm no expert on the condition of the transmission fluid... The stuff looks pink, does not smell burnt, and is up to level as defined by the users manual.

My only complaints about this tranny, ( other than the surging issue) are:
1.) Everytime you let off the accelerator, the TCC disengages.... even if you're doing 70 mph....... WTF is up with that ? That just seems like such a ridiculus thing to do, unless the object is to expose the TCC to unnecessary wear.... I hear this is by design.

2.) I can be going along at a constant speed and then gradually start to push down on the accelerator.... like at the bottom of a slight hill. I would expect the transmission to stay in that gear since the speed was approximately the same, but more demand for power being called upon by the motor..... But, all of a sudden, the transmission shifts up and now there'* not enough pulling force to handle the hill. The accelerator then has to get pushed down more until finally the computer shifts down 2 gears..... It'* almost like the "shift-tables" in the computer have too much weighting on the speed variable on not enough on the throttle position...... That'* just my uneducated guess.

I really do appreciate all you guys input.

Jack

I'm at about 1000 feet above sea level.

I experience the exact same issues. Some of us have tried adjusting our throttle position sensor (TPS) because it seems the PCM doesn't 'know' you're giving it very much throttle to get up a small incline. I'm to the point where I think I'm going to try a brand new TPS, just to see if it makes any difference. Other than that, I've always felt like the only way for me to alleviate all these little issues is to get a completely new transmission. Maybe I'm wrong, but I get the feeling it surges and shifts oddly due to age and wear.

Basically, I have no idea how to fix the problem :( . I sure wish I did, though.