I have a 1995 Buick Regal GS Coupe 3.8l, typical oil leak (don't know about motor internally) that I have driven for the last 10k up to ~186,000. I know that doesn't entirely matter with these transmissions. I at first experienced TCC shudder/lockup (and associated code) issues but I simply replaced ignition wires & plugs, and haven't experienced that problem since, including the code. I also have typical fouled coolant level sensor saying "low coolant" when it is just fine, and cools effectively.

I've been losing TCC and OD. I will lose it with cold fluids IF I try to cruise between 40-47mph (1900RPM in 3rd/locked), and will also lose it after I reach operating temperatures. This leads me to believe I'm in "hot mode" as described by some random forum post I found while searching for results - can anyone help me confirm or deny this? Every time I have taken it to get tested for a code, the tester insisted I shut off the engine (usually to wait on them) and subsequently restart, which I know resets this condition temporarily until under load, as I have used it on-highway. So should I maybe try to get someone to test it while it'* still in the "no 4th" condition or what? Do I need to spring for my own tester? I've been told it "doesn't work" with whatever standard they use at GM shops nowadays, so I need to look into that better as well. Keep in mind I'm a poor college student please!

I did not think about it until now, 80mi from my same model year parts car, but the optimum ignition signal (when I replaced wires & plugs) probably also increased vacuum signal reliability for the modulator. Is there any good way to confirm my modulator? Should I rob the other car'* unit and see if it makes a difference? I have a vacuum gauge and the tees necessary to measure a fully-warmed-up idle reading, though my idle speed fluctuates gently between 700-750 with no AC or significant electrical load.

The transmission has been to a specialist who has rebuilt many of the same design but could not correct my issues. He has tested all involved solenoids and even replaced a set, all under personal warranty to satisfy the customer. He also changed my gearset with what I am assuming is for a significantly higher GVWR due to a lower 2nd (or maybe final drive) than stock, all to try and fix my issues. I felt like he took the transmission in & out enough (4 times) for only $1200, with a free run-through of a 727.


On the bright side, I get a rock solid 20-21mpg anywhere in 3rd or 4th. Can anyone offer a green kid some advice on these things?

I apologize for posting this before I found the 4T60-E info thread (also the search feature), I will now be returning here shortly to study up.

hmm ive got roughly the same issue in my 97 ssei with a 4t65e-hd but only when i run it up over 200 degrees ive not found the cause either im about to start looking at my computer if it doesnt go away after i rebuild the motor and trans sorry im not much help im not really a computer trans expert im good with old school rwd trans

and i encourage you to stick around and enjoy yourself

We have a great trans rebuilder here, SGP358, I'm sure he will chime in soon. Not totally sure on your year and the 4t60 but there should be a TCC solenoid switch on the brake peddle. That'* a possibility. Let'* see what Steve has to say.

First off, welcome to the forum. I'm glad you stopped by here. We have a guys here that rebuild transmissions in their sleep, lol.

I have noticed that these transmisions run MUCH better with a transmission cooler. People solve a lot of problems over on another forum I'm on by installing transmission coolers in their 4T60E'*. I would very highly recommend that.

If at any point you realize that you need a new transmission, I do have a perfectly running 4T60E transmission from my 95 Regal (I swapped engines recently for a supercharged 3800), with 217k miles and was rebuilt at 144k miles, that I would sell you for cheap. PM me if you're interested; it has a fresh fluid and filter change with Dex6.

Welcome to the forum! You don't need to buy your own code reader. Auto parts stores are more than happy to read your codes for free.

Being a '95, though, there'* a very good chance your Regal runs OBD 1.5. You may need to do some hunting to find someone with the proper code reader. If you can't, then I do suggest buying a reader of your own.

The 94 and 95 Regals are OBD1.5. I would know because I've had one for the past 8 years.

Most auto shops won't be able to scan OBD1.5, but places like Pep Boys might. The absolute best way to scan an OBD1.5 Regal for codes is using an ALDL cable. You run TunerPro on a laptop, and using an xdf definition file, you can scan for codes. I bought mine for $60, and since I don't need it since I'm running OBD2, I can sell you that one too and Robert Saar on here would be more than happy to walk you through how to use it.

Okay, in steps here....

Concerning transmission cooler:
Do I not have to worry about the issue of running "cold" fluid through the system? I've been told this is a bad thing concerning my 727 (Scout II) which is why the radiator cooler should not be bypassed. I have not looked into it enough, but is there an existing loop integrated into my radiator for tranny fluid? If I bought a cooler, would it be plumbed in series?


I am afraid that I probably won't be able to afford to purchase much outside of maybe a cooler and the required hardware. I appreciate the offers, however, and would definitely like to be capable of reading my computer output on this laptop. I will be looking into the proper connections for doing this. I have just now obtained the tunerPro install package. Will I need a standard 12-pin ALDL?

In an off-subject rant, my 3.8 is currently responding in an "odd" way during accel, such that if I allow it to shift into the 1900-2100RPM range (with light accel) it will not respond to throttle changes quickly and just hangs up at 2100. This is not TCC lockup, but instead more like a "dead spot" in the fuel delivery or at least some sort of significant lag in system compensation, i.e. lack of power. The engine does not begin to respond correctly until 2500RPM+. I would hope that a computer readout of various systems information would also help point out the anomaly there. Not to mention I'd like to become familiar with MPFI just in case the Scout II gets allotted some spare dollars down the line. Perhaps my injectors need servicing?


I appreciate all the responses and look forward to working out my own issues on this forum, and maybe even learning a thing or two about computerized machinery.

I bought my ALDL cable for $60, so $40 shipped to you if you want it.

Transmission cooler can be and should be hooked up in a series. You run fluid through the radiator, then through the cooler, and back to the transmission. It would not be a good idea to bypass the radiator because the transmission can overheat when you're sitting in traffic on a hot day and there'* no air coming through it. This both ensures that its not too cold in the winter and not too hot in the summer. I have an RV sized radiator cooler that is absolutely massive and the only problem I ever ran into in the 40k miles I used it is that on very cold winter mornings, it would take a few minutes for the transmission to warm up to a temperature where the torque converter clutch would engage. That happened rarely and was no reason for concern.

When was the last time you did any sort of tuneup? Fuel filter, air filter, MAF sensor cleaning, spark plugs and wires, replacement of vacuum hoses, etc?