Torque converter failing?

[Buck531]

What generally happens when a TC fails?

 

Reason I'm asking. Lately the car has been acting strange (when isn't it). At a dead stop, I give it say half throttle, and the rpm's go up to 3k (as normal.. it's a 3800 stall), and then it just bogs down hard. You can really feel it to.

 

Slowly it will get up to speed, then shift gears and it's fine.

 

The trans was rebuilt compeltely not even a month ago.

 

Is it the TC that's going or something else with the trans?

[Guest Elinar Longsight]

I deleted all post that were not following the rules. Stay on topic, post ONLY if you have a helpful solution or honest opinion about the problem. Anymore off-topic bs will get you a strike.

 

Thank you and have a nice day. ~ Tina

[gillbot]

Can you check pressures. You could have slippage elsewhere or the TC could be locking too soon. Not sure of the year on yours but is the tranny PCM controlled? Can it be logged with a scanner?

[Buck531]

I can try to scan it. with an autotap. What parameters should I scan for? It doesn't happen all the time either .

 

There was another guy who had a 3800 stall in his Monte (not the same manufacture), but his was doing the same thing. the TC was failing. He took it out and put the stocker back in and it was ok.

 

I'm not TOO concerned about it. It's under warranty, and I'm pulling the motor within a month and I'm going to send this one back to the company where I got it to have them look at it.

[Doug1647545489]

If the one way roller clutch inside the stator fail you'll have sluggish acceleration.

[Lustalbert]

any discoloration in the fluid, or metal flakes?

[Buck531]

Originally posted by Lustalbert:

any discoloration in the fluid, or metal flakes?

Nope. looks perfect like it should.

 

Doug. Hmm. interesting. it's intermittent too. Doesn't happen all the time.

 

hopefully I'll find out soon enough when I do the engine/everything swap here within a few weeks.

[Doug1647545489]

Originally posted by Buck531:

Nope. looks perfect like it should.

 

Doug. Hmm. interesting. it's intermittent too. Doesn't happen all the time.

 

Then is probably not the stator clutch that I was talking about. When they go thereno going back. Doesn't really sound like a torque convertor issue either.

 

Usually the TCC won't apply in first gear and most TCC problems I have seen either its not applying or not disengaging. (stalling the car).

 

To see when the TCC is applying look at TCC PWM Duty Cyle on autotap. Its gonna be a percentage since the TCC is pulse width modulated and actually allows the lock up clutch to slip. See if it applys in 1st gear. Most cars only apply is in 2nd, 3rd, 4th or above 50 mph.

[Buck531]

It feels like it's almost "slipping" when I go, but it's only at a dead stop, every other gear is fine, and it's intermittent. i mean. at one stop sign/light it'll do it, and not even 30 seconds later it'll stop. I could also let off the gas and get back into it and it's fine.

 

Remember.. my friend had the exact same problem. 3800ish stall, would bog down real hard. Just like mine. It ended up being the TC.

[Doug1647545489]

Originally posted by Buck531:

It feels like it's almost "slipping" when I go, but it's only at a dead stop, every other gear is fine, and it's intermittent. i mean. at one stop sign/light it'll do it, and not even 30 seconds later it'll stop. I could also let off the gas and get back into it and it's fine.

 

Remember.. my friend had the exact same problem. 3800ish stall, would bog down real hard. Just like mine. It ended up being the TC.

Torque COnvertor are very simple. THeres really nothing in them that can be intermittent. If the one way roller clutch goes bad its usually toast. If the fins on the impeller or the turbine get damaged they can't fix themselves. And like I said on the TCC. When the TCC solenoid fails its either stuck on or off. And you know that it's not stuck on. Being stuck off wouldn't really have much (if any) affect on accelleration. The bogging really does sound like a bad one way roller clutch but the interminttent part leads me away from that as being the problem. Just to make sure I'll email my Automatics teacher from last session to see if it could interminttent.

 

hmm its also hard to diagnose problems over the internet smile.gif

 

[ 26. July 2005, 07:12 PM: Message edited by: Doug ]

[Buck531]

Originally posted by Doug:

Torque COnvertor are very simple. THeres really nothing in them that can be intermittent. If the one way roller clutch goes bad its usually toast. If the fins on the impeller or the turbine get damaged they can't fix themselves. And like I said on the TCC. When the TCC solenoid fails its either stuck on or off. And you know that it's not stuck on. Being stuck off wouldn't really have much (if any) affect on accelleration. The bogging really does sound like a bad one way roller clutch but the interminttent part leads me away from that as being the problem. Just to make sure I'll email my Automatics teacher from last session to see if it could interminttent.

 

hmm its also hard to diagnose problems over the internet smile.gif

yep.. diagnosing stuff on the net does suck.

 

My buddy also said the fins could be "bent" from too much city driving and that high of a stall. Basically having it in the stall (under 3800 rpm's) for a long time. I dunno if that makes any sense or not.

[gillbot]

I was thinking the same, shouldn't be intermittent if it was the TC.