I have a 1995 Roadmaster with only 164,000 miles. My problem occurs when I am running over 45 mph and holding it at constant speed. If I increase speed slowly, the car surges roughly. If I increase speed quickly the problem doesn't occur. I tried pulling it into 3 instead of OD and it does the same thing at that speed. I had a Buick service center check it, and he said it was the transmission. I found out that the mechanic drove it to make his assumption rather than put it on equipment. Then I took it to an independant tranny shop, he drove it and said it was ignition wiring. Anyone have any simular experience? LKeller

when you say surges do you mean it accels slowly or what is it exactly doing. Around 45-55mph in third and in OD the torque converter will lock up. While it's lockup you should notice it will accelerate slowly unless you give it more gas to unlock the TC. Have you checked the trans fluid to determine it's color and if it's burnt? When was the last tune up performed on the car?

Matt

When I am cruising 45 mph or faster (not accellerating or reducing speed), and I decide to accellerate slowly like 1 to 5 more mph, say like keeping up with traffic; it jerks intermittently forward and backward in speed, untill I either push it down or hold it steady again. If I push the accellerator like 1/2 down or more, this problem doesn't show up. In other words, if I don't punch it somewhat, it does the fast and slow increase of speed. It sounds to me like (from what you say about the converter locking and unlocking) the converter is quickly unlocking and then locking up to cause the quick jerking that I feel. What could that be caused by? I had the engine tuned at 95,000 miles and again at about 125,000 miles, each time plugs were replaced and the second time ignition wire also. Tranny was rebuilt under warrenty (5 year warrenty) by GM. It lasted 1 year and 3 months and the planetary gears were destroyed. When driving from Indiana to Florida, it blew again near Cordelle, Georgia and Master Transmissions rebuilt it this time. They said they put in extra bands, increased the oiling capacity and replaced the valve body. It lasted several years and went out again. J & L Trans. in Kokomo, IN rebuilt it claiming Master had installed a used tranny (?) 2 years later its acting as I descibed earlier. The tranny oil was checked - it smelled and looked OK. I have faithfully with a lot of $$ kept this car up since I have planned to keep it. Thanks - Lkeller

Yeah I learned the first $1700 about who to trust w/ 4l60-e transmissions and it's only a few people. Many people claim to build them but it's not like a Turbo 350. You can't slap the thing apart and slap it backtogether. It's like woman. You have to handle it just right putting it back together making sure everything is right :)

That being said it could possibly be the trans. There's a solenoid in the trans called a TCC. If my memory serves me correctly it's full name is the Torque Converter Clutch soleniod. it makes the converter lock and unlock. If it becomes faulty I do believe it can cause a surging. I would have that checked.

There's also a TBS for the problem you're describing

http://www.geocities.com/MotorCity/6577/b-body_576517a.pdf

I'm not an expert (just a man w/ good opinions) but Bernard @ TeamTripp really knows his stuff. If something can't be resolved give him a email, or if you even want to replace the trans w/ something you know is going to work give him a call

http://www.teamtripp.com/

I sent an email to Team Tripp asking about my problem. Bernard said it sounded like Converter Shudder (a much better discription than mine), either due to a bad converter or a leak in the apply circuit. He also said that it could be a possible engine misfire which is amplified by the converter locking up. Wow! Since I figure that the TCC Valve is part of the apply circuit, I'm having a mechanic replace mine, just to find out (Part changer diagnosis). Incidently, I can't seem to get the geocities web address to come up. I would like to see what GM said about this. Thanks - LKeller

okay. Let me know what it ends up to be. If it's not the trans it could possibly be a missfire like bernard mentioned or a faulty EGR valve.


This is what the geocities site said.

1996 Chevrolet Impala SS V8-350 5.7L VIN P SFI
Vehicle: All Technical Service Bulletins
Chuggle/Surge and Intermittent DTC 32
File In Section: 6E - Engine Fuel & Emission
Bulletin No.: 57-65-17A
Date: June, 1996
Subject:
Chuggle or Surge and an Intermittent DTC 32 (Reflash Calibration)
Models:
1994-96 Buick Roadmaster
1994-96 Cadillac Fleetwood
1994-96 Chevrolet Caprice, Impala SS
with 5.7L Engine (VIN P - RPO LT1) and 4L60-E Automatic Transmission
This bulletin is being revised to add the 1996 model year and to update the parts information chart. Please discard Corporate Bulletin
Number 57-65-17 (Section 6E - Engine Fuel and Emission).
Condition
Some owners may comment on a chuggle or a surge condition between 40-65 mph (64-104 kmph). Also some vehicles may set an
intermittent DTC 32 (1994-95 vehicles only).
Correction
Install the proper flash calibration listed from table in Parts Information.

Hi Buffman - I was to have a mechanic replace the TCC valve in the transmission, but he back out because he thought everyone had been working on my Roadmaster, so I waited a while and took it to a second Buick Dealership in another town. They said it was the Plug wires, so I waited for them to contact me when they were to recieve them from Ohio. Much later, I called their parts dept. and they said that service never ordered them, so I ordered them myself. After installing the wire set, I haven't had a problem again and it has been about 3 weeks, so it looks like that took care of it. What fooled me , was that when I floored it, it never cut out or anything, just when I slowely increased speed from 45 and above. Thanks for the help and keep up the good work - Lawrence Keller

Glad you got everything taken care of.

Matt

It could be your knock sensor retarding your time. This causes that "stutter" which you've described as surge. If you have a loose exhaust manifold, your knock sensor could mistake loud exhaust noise for knocking rods, etc., and then retard your engine for no good reason. This will happen around 45 mph, when you're revving low and the knock is louder (relatively). When you speed up, you eliminate the knocking with higher revs: the higher the revs the smoother and quieter the knocking becomes. Check you exhaust manifold, make sure none of the studs have broken. All that being said, do you hear a knocking when you start the engine cold? Just my 2 cents.

I have a 1995 Roadmaster with only 164,000 miles. My problem occurs when I am running over 45 mph and holding it at constant speed. If I increase speed slowly, the car surges roughly. If I increase speed quickly the problem doesn't occur. I tried pulling it into 3 instead of OD and it does the same thing at that speed. I had a Buick service center check it, and he said it was the transmission. I found out that the mechanic drove it to make his assumption rather than put it on equipment. Then I took it to an independant tranny shop, he drove it and said it was ignition wiring. Anyone have any simular experience? LKeller

Hi Portholes - Thanks for the additional tip. I have never had any knocks in my RM. Before I had several gaskets replaced for oil leaks, I was having some tappet racket when it was a little low on oil, that's all. Lkeller