New Guy with Tranny Problem HELP

[matt1987]

Hi, I have a 95' Grand Prix with a 3100 v6 in it and recently the tranny has started acting strange. It is intermittently shifting in and out of overdrive when accelerating from a coast or stop. Once I am going about 40-45 it is in 4th gear like it should be, but when taking off it seems like it goes into second but then shifts into overdrive at about 15-20 mph. Can anybody help me out?? I appreciate any help!!!

[Regal_GS_1989]

Sounds like an electrical issue to me. A shop with a scanner should be able to figure it out.

[Intlcutlass]

Give it a tune up....trust me.

 

Clean off the terminals to the coilpacks, and change the plugs. Sounds crazy I know, but I had the same problem on my wifes 95 cutlass with a 3100. That's a 4t60-e.

[matt1987]

I have tried putting it into first and manually shifting it, but as soon as it goes into second it immediately shifts into overdrive so it is in overdrive at like 25 mph once I get to about 40-45 it stays in overdrive and its fine.

[Intlcutlass]

I had misread your original post---I am sorry. I thought it was shifing OUT of OD at speed... :oops:

 

I agree with Regal.....

[Crazy K]

Your car has the 4t60-E transmission

ok my service manual says:

condition:1st and 4th gear only

Inspect Componet: "A" shift solenoid For On

cause: foreign material, pcm signal grounded, or pinched solenoid return wire to ground.

 

The transmission has an "A" and a "B" solenoid. these control the transmission shifts. Your problem stems form the shift solenoid being stuck in the "on"/engaged position. It is either due to some crud it your tranny causing it to stick or due to an elctric problem.

 

However are you saying that it's intermittant?

 

BUT!!! I'm not certain if that is The exact problem. Are you saying that when it fouls up it shifts right from 1st to 4th(O/D)?

 

You probably will have to have it fixed at a reputable shop. It seems to be a shift solenoid problem. Talk to a few mechanics. a scanner will tell exactly what the tranny is doing. I think it's a solenoid or electric problem, based on what I understood, which means the tranny probably doesn't need a rebuild. (some shops will want to do that)

Try going to your local library and reading a Motor or Mithell manual that details Problem diagnosis for your tranny.

[Regal_GS_1989]

Your car has the 4t60-E transmission

ok my service manual says:

condition:1st and 4th gear only

Inspect Componet: "A" shift solenoid For On

cause: foreign material, pcm signal grounded, or pinched solenoid return wire to ground.

 

The transmission has an "A" and a "B" solenoid. these control the transmission shifts. Your problem stems form the shift solenoid being stuck in the "on"/engaged position. It is either due to some crud it your tranny causing it to stick or due to an elctric problem.

 

However are you saying that it's intermittant?

 

BUT!!! I'm not certain if that is The exact problem. Are you saying that when it fouls up it shifts right from 1st to 4th(O/D)?

 

You probably will have to have it fixed at a reputable shop. It seems to be a shift solenoid problem. Talk to a few mechanics. a scanner will tell exactly what the tranny is doing. I think it's a solenoid or electric problem, based on what I understood, which means the tranny probably doesn't need a rebuild. (some shops will want to do that)

Try going to your local library and reading a Motor or Mithell manual that details Problem diagnosis for your tranny.

 

That sounds about right. I worked at a tranny shop and had to diagnose a 98 blazer that would start off in 3rd gear, and with the scanner hooked up to the data stream, its fairly easy to pinpoint. and if you take it to a shop that tells you it needs a rebuild, get the hell out of there.

[matt1987]

Thanks for all the help. The kicker is I just bought the car thurs dec. 1 it was fine until about 3 days ago. The dealer is going to pay for it to be looked at where they get there mechanical work done, but If they don't find anything I am going to take it to the Pontiac Dealer anyway just to be sure. If its electrical I can deal with that I hope that is all it is. I appreciate the help if you guys can think of anything else please post any info you have.

[matt1987]

When I got the car back from the shop, they said it was fine. They said it didn't do anything. They drove it twice and put it on a scanner and nothing came up. ???

[Crazy K]

intermittant condition I suppose. When my 95 CS acted up, I wiggled the plug at the front of the tranny, and never saw my problem again.

[matt1987]

Well, The pontiac dealer called me today and said they have never had this problem with a car before... :? They still have not given me a definite answer to what the problem is. They said there is something wrong with the tc locking up. So I am thinking solenoid?? They are going to show me a way to pull the lock up wire so the car only has 3 speeds no overdrive. Thats great but won't that burn up the trans???? The write up guy said maybe a valve body?? Like I said I still don't have an answer to what is wrong with my car. I figure I will replace the solenoid and see what happens. He said I can sell you a new trans and labor for $3400. I don't have that kind of money so thats out of the question. I only paid $3500 for the car. Gotta love the dealerships...

[Regal_GS_1989]

Umm, if you pull out the lockup wire, the car will have 4 spds, and it WILL have overdrive. Just the torque wont lock up. And no, it wont hurt the trans, just you gas milage, and even that wont make a huge difference. You also said that you took the car to a shop, and the scanner didn't show anything. It may be related to the convertor itself. I worked at a tranny shop, and i had to pull the tranny on some guys motorhome (That was fun ) because some shop in Minnesota had put in the wrong Torque convertor.

[matt1987]

Here is what the dealer wrote up for a description of the problem which is what I told them was happening. Just so you everyone knows what exactly is happening. "Trans seems to go into overdrive at times after 2nd gear then will drop to 3rd then go into overdrive again but this time when it should, has sometimes when slowing for light to 10 mph has gone into overdrive when trying to accelerate from there. Seems to feel bump when going into overdrive from second and from 3rd." They said they have never had this problem. Any idea on cost to replace the tc?? How hard is it to unbolt the trans from the motor I have a garage, air tools, and a cherry picker. Depending on how much a new tc installed would charge.