Rob95CS Posted August 17, 2004 Report Share Posted August 17, 2004 Here's my problem... on a cold start, my torque converter clutch will engage properly in overdrive (engages at 45 mph) for usually around 20 miles of normal driving. After that, it will just quit engaging, causing my engine to be running about 2300 RPMs at 55 MPH instead of the normal 1900 RPMs and my gas mileage suffers considerably at higher speeds. If I drive it harder than normal like pushing it hard to pass another car, or even taking off quickly from a stop sign, it will quit engaging even sooner. It won't start working properly again until my engine cools for a while in the driveway. Any idea on what may be causing this? There are no unusual sounds coming from the TC and the car drives fine other than this. Quote Link to comment Share on other sites More sharing options...
tloftus Posted August 17, 2004 Report Share Posted August 17, 2004 You could replace the TCC Solenoid. Depending on the motor you have. I have a 2.8 and it was pretty simple to swap out. Mine was just the opposite though, it was keeping the Torque Convertor locked up so it would stall and die when I came to a stop. Quote Link to comment Share on other sites More sharing options...
Rob95CS Posted August 18, 2004 Author Report Share Posted August 18, 2004 Well, it's not that it doesn't lock up at all, it just fails to lock after being driven for a while first. Could this still be the problem? Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted August 19, 2004 Report Share Posted August 19, 2004 Yes. TCC no doubt. Quote Link to comment Share on other sites More sharing options...
tloftus Posted August 19, 2004 Report Share Posted August 19, 2004 What motor do you have? Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted August 19, 2004 Report Share Posted August 19, 2004 3.1/4T60 and 3400/4T65e Quote Link to comment Share on other sites More sharing options...
musthavemuzk Posted September 12, 2004 Report Share Posted September 12, 2004 and boy was that fun when i did my 93 GP 3spd. took 2 nights of cussing and such. but i did it and it helped Monty Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 12, 2004 Report Share Posted September 12, 2004 thats a common problem (raises hand) I forgot what exactly causes the problem, but GM released a TSB on it, I have yet to look it up but I think a new solenoid solves it. Not the hardest thing for me to do, but I have some experience with dropping the frame and messing w/ the trans. Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted September 13, 2004 Report Share Posted September 13, 2004 thats a common problem (raises hand) I forgot what exactly causes the problem, but GM released a TSB on it, I have yet to look it up but I think a new solenoid solves it. Not the hardest thing for me to do, but I have some experience with dropping the frame and messing w/ the trans. Brian, I believe that TSB had something to do with the solenoid grounding internally or something to that nature. Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 13, 2004 Report Share Posted September 13, 2004 I wouldn't doubt it. It sucks too because before the solenoid just quits working, it will engage lockup but like only halfway, so the rpm will drop but when you accelerate a little bit, the tach moves up a little without disengaging. THats NOT supposed to happen and I think it's as bad as driving a stick shift with the clutch halfway down. So when I see that happen, I'll take my foot off the gas (disengaging lockup) then accelerate hard, that usually kills the solenoid for the remainder of the drive. As you can imagine I do a LOT of highway driving! Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 21, 2004 Report Share Posted September 21, 2004 I have the same issue. Only locks up at exactly 90mph when the rpms drop around 3000. Are those clutch solenoids expensive? Quote Link to comment Share on other sites More sharing options...
TeeJay3800 Posted September 21, 2004 Report Share Posted September 21, 2004 Here's my problem... on a cold start, my torque converter clutch will engage properly in overdrive (engages at 45 mph)... It should also engage in 3rd gear. My TCC locks up at 33 MPH in 3rd at light throttle. Quote Link to comment Share on other sites More sharing options...
vtirocz Posted October 10, 2006 Report Share Posted October 10, 2006 I am experiencing the exact same problem with my '90 Lumina 3.1 w/ the 4T60 trans. What is the typical root cause of this?... TCC solenoid itself? It sounds like a common problem. I'd appreciate any help. Thanks, Jim Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted October 11, 2006 Report Share Posted October 11, 2006 Here's my problem... on a cold start, my torque converter clutch will engage properly in overdrive (engages at 45 mph)... It should also engage in 3rd gear. My TCC locks up at 33 MPH in 3rd at light throttle. What?!?!? I've never heard of that. (But that Doesn't mean it doesn't exist) I am experiencing the exact same problem with my '90 Lumina 3.1 w/ the 4T60 trans. What is the typical root cause of this?... TCC solenoid itself? It sounds like a common problem. I'd appreciate any help. Thanks, Jim The Torque Converter Lockup Soleniod. I've heard its a PITA and requires pulling the Trans to change. My Band-Aid fix was to put a free Trans Cooler (my dad gave it to me) on it to keep trans temp lower, since the TCC Soleniod only failed once it got hot, It helped a lot and it only failed on the hottest of days, or if you drove it thru town. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted October 11, 2006 Report Share Posted October 11, 2006 What?!?!? I've never heard of that. (But that Doesn't mean it doesn't exist) Yeah, it should lock up in 3rd gear around 35mph with normal throttle. Quote Link to comment Share on other sites More sharing options...
Brian P Posted October 11, 2006 Report Share Posted October 11, 2006 I did find the exact problem to my old tranny, it was the PWM solenoid. The TCC solenoid can still go bad, but the PWM is worse. Its sole function is to control fluid pressure to the solenoid for lock-up. Over time they succum to heat. Simple way to test this is to remove the ground connection on the main tranny plug for the PWM solenoid. It was position C. The only effect by doing this at least on '94-97 cars is the clutch will engage firmly rather than softly. I had no issue with this and it was nice having it back (till I blew that tranny, but that's another story). BTW, pre '94 uses an accumulator piston to soften the TCC apply, instead of this PWM solenoid. Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted October 11, 2006 Report Share Posted October 11, 2006 What?!?!? I've never heard of that. (But that Doesn't mean it doesn't exist) Yeah, it should lock up in 3rd gear around 35mph with normal throttle. Yet another reason my tranny blows Brian whats this PWM/Accumulator Piston you speak of? And what do we disconnect to test it? Pics are Cool <----Knows Little to Nothing About Transmissions Quote Link to comment Share on other sites More sharing options...
Brian P Posted October 11, 2006 Report Share Posted October 11, 2006 Earlier tranny's (93 and older) the fluid is directed across a spring-loaded piston in the channel plate when TCC apply is commanded. This "softens" the apply so it doesn't apply harshly and startle the driver The PWM (pulse width modulated) solenoid effectively does the same task this piston would have done, only the PCM controls this electrically via regulating the fluid pressure. Cars with the PWM solenoid do not have a piston (accumulator) in the channel plate. Like I said, I just removed the wire that the PCM variably grounds to control the PWM solenoid. I'll take a pic of the book literature, actually wait, here: Bottom diagram, location C: Quote Link to comment Share on other sites More sharing options...
vtirocz Posted October 12, 2006 Report Share Posted October 12, 2006 Brian P., You're saying that disconnecting the PWM solenoid solved your TCC (slipping) problem? Since my Lumina is a '90 it would have the accumulator piston. Is there anything I could do with the accumulator piston to help my problem. In my case the TCC is being commanded to lock, but there is not the correct amount of fluid pressure after it gets hot (so it will be fine for the first 20 min, then not work). I have installed a big trans cooler, but still have this issue. Any suggestions to help fix my problem? Also, how long will the transmission last with the TCC slipping? It hasn't gotten any worse over the past 8500 miles. Would it just die with no warning? Thanks, Jim Quote Link to comment Share on other sites More sharing options...
Brian P Posted October 12, 2006 Report Share Posted October 12, 2006 Yes, it solved my slipping problem when hot and apply failure after a length of driving. There's nothing you can do with the piston. TCC solenoids can still fail, but in my case it was the PWM solenoid. Not everyone with my setup will have the same problem. I tested my TCC solenoid and found it to be good. Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted October 12, 2006 Report Share Posted October 12, 2006 How Can You Test the TCC Soleniod on the 4T60(93-pre)? Quote Link to comment Share on other sites More sharing options...
Brian P Posted October 12, 2006 Report Share Posted October 12, 2006 just manually ground the TCC sol ground wire (would normally get grounded by the PCM) What I usually do is run a thin wire into the tranny plug's terminal, then run it up the hood, into the car thru the drivers door. When you want to test, touch the wire to bare metal, like a door panel screw to ground it. It should apply. Quote Link to comment Share on other sites More sharing options...
Dark Ride Posted October 13, 2006 Report Share Posted October 13, 2006 just manually ground the TCC sol ground wire (would normally get grounded by the PCM) What I usually do is run a thin wire into the tranny plug's terminal, then run it up the hood, into the car thru the drivers door. When you want to test, touch the wire to bare metal, like a door panel screw to ground it. It should apply. Sweet <--Looks around apartment for piece of wire...No Luck Quote Link to comment Share on other sites More sharing options...
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