Lockup Torque Convertor, 94 LeSabre

Take off the transmission and the TC will come right off.

I'm not trying to be a wise guy, but if you have to ask this question, then you need more than the advice you can get in a newsgroup. Unless, of course you want to wash your hands and run to the computer to post a new question every five minutes while you're trying to drop a tranny.

It's certainly a job you can do yourself if you're at all mechanically inclined, but do yourself a favor and go to the local auto parts store and buy a Haynes manual for your car. It will cost under $20 and it will give you a good set of instructions for how to work on your car.

You'll be in for a good amount of work. Yanking a transverse mounted tranny means getting into a lot of places that you'd swear it was impossible to do. You'll be taking apart things that have nothing to do with the tranny. You'll swear that auto design engineers have a perverse sense about them. You'll certainly ask yourself why in the hell you even got into this. But... you *can* do it.

I guess I should have asked in my previous reply to you - why do you say it needs to be fixed? Start with giving us your engine size and tell us what the symptoms are that have you believing this. Wouldn't you love it if you could fix your car without yanking out the tranny?

Ya know - maybe it's because one gets tired of typing "what engine is in the car", but doesn't it just get annoying when people say "my car is broke, what's wrong with it?".

I understand that not everyone works on this stuff and a lot of people just want to drive their cars and not worry about all the details, and I have no problem with that. But... this is real life. Where can you possibly go with any sort of problem and expect answers without providing common sense background information?

Sometimes my bad attitude has a way of showing itself...

The Lockup Torque Converter mechanism, at highway speed, engages and disengages making the car vibrate. I press the brake pedal very slightly and it stops the "vibration". This indicates the Lockup Torque Converter is at its critical parameters for trying to decide whether to lock up or unlock. Its a 3.8 engine. Sorry, I though all 94 Buick LeSabres where 3.8 L. I would like to know if someone knows where this thing is located. I looked in my Haynes manual but I couldn't find anything about it. Thanks in advance.

I have been plagued with the same problem. I must tell you is may NOT be the TC at all. It can react to missing in the engine. I'm about $500 into the issue, just having had the fuel pressure regulator replaced. I THINK it's fixed. I 95% certain it's not the TC itself because addressing misses in the engine can make it go away.

A good place to start is the plugs and plug wires. Then check the fuel pressure.

Ed '95 Park Ave Ultra (3.8L with supercharger)

Trust me - Ed is the voice of experience on this problem. Ok Ed - this is yours, you run with it.

But if I deactivate the Lockup Tork Converter the car works fine. I was told that in some cars the lockup thing can be reached just by removing the transmission oil pan.

Engine misfire will be amplified when convertor is locked. Look for and eliminate misfire before worrying about the LTC.

Dave

The lock up drops out for more than one reason. That's what Ed is trying to explain to you. The torque (not Tork) converter is almost *never* the problem. Of course the car works fine if you drop the lock up out. Your problem is that it won't remain locked up and is hunting. Ed is trying to explain to you the *very same problem* which he has just gone through - with considerable trial. There are other areas of the car to look at long before the torque converter when this happens.

It's clear you don't know much about these things, and that's fine, but at least listen to what folks are telling you - even if it means asking them for more detail. You can overlook a lot of very good advice if you don't.

Just because the clutch locks and unlocks does not mean it's bad. It could be any one of about 25 things: The computer control circuit could be bad. Pump could have low pressure. TC soleniod could be warped. Seals bad. Any one of 17 sensors could be going bad. Etc. In fact, it may not the clutch at all. It could be bad plug wires. (See Ed's post.)

Injectors would be way down on my list of things to check. First thing would be plug wires. Then fluid pressure at the clutch.

I assume 4t60E, ODBi ? Test port on top of the trans. Looks like a plug. I don't know what the specs are for that year & application though. You will have to look in a GM trans manual for that info. Hook your scanner to the obd link and see what the pressure is when the ecu sends the lock up signal.

Sorry, I wasn't watching this thread for a few days.

As I now see it, the problem is this: The TCC (torque converter clutch) engages and releases in response to load. The idea is when the load is light, the clutch engages and engine revolution is directly connected to the output, without going through the "fluid link" of the TC. This is an economy measure. It all works great until the engine develops a habit of intermittent missing. When this happens, it drives the TCC crazy... it's jumping in and out all the time. That's what you feel. If you disable the TCC, the engine still misses but you probably won't feel it, just like you don't in cars with out the TCC business. But obviously the thing to do is fix the engine, not disable the TCC.

As for me, the car has been fine since having the plug wires, plugs, fuel filter, and fuel pressure regulator changed. The last item is what seems to have fixed it. Time will tell. I will report back if it starts doing it again. BTW, the air mass flow sensor was replaced somewhere in there too, but that was a wasted $200 + labor exercise.

All of that said, I do plan on taking it to a tranny shop to have it serviced, as it's been about 70K miles.

Ed

Ok Ed - archive your response for future cut-n-paste, 'cause you're now the official lockup guru of the group. We'll be expecting you to rise to the occasion every time a new post hits.