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Pontiac Grand Prix Transmission Problems



  • I would have my computer checked for this problem first.
  • My Grand Prix is also shifting hard and the RMP's are jumping around. I was wondering where could I find this new software upgrade. I looked on the search sites and i can't find anything about the upgrade.
    please help :cry:
  • Hi karrick,

    Sorry to be so long in replying.

    I think I must have been one of the lucky ones. Since rob94 posted the idea of the upgrade, others have asked where to find it and it seems to be a mystery.

    My car supposedly had the most current software, but the mechanic at the garage called someone in Detroit. They uploaded a new, but unreleased version on my car. Since that time, no one else on here seems to have been successful at having someone find it.

    My suggestion to you is to print this stuff off and take it to a dealership. Unfortunately with the shape GM is in right now, you may not get much help.

    I hope you get your problem fixed! I feel for you.
  • About a week ago my 01 grand prix just stopped shifting into overdrive. Im wondering if it is the speed sensor. Other than that it shifts good.
  • I have a 1999 Pontiac Grand Prix, 3.8 V6, supercharged.
    When the car warms up a little, I get a ticking noise somewhere around the trans pan/engine pan area. When I drive it goes away but when I coast down to idle the ticking starts. When in drive idle it ticks, when in neutral or park idle it ticks intermittently. :sick:
  • I have a 2001 Grand Prix GTX, modified GTP ~77K miles on it. Anyway here in the last few days when driving slowly it would shift really hard into 2nd, but shifting into anything higher was fine, but not OD this would also only happen after I have been driving it for a hour or so, and about the same time the check engine light would come on, flagged a code of P0716, but would also clear by itself.
    I searched the net to no avail and the folks at the local shop were clueless. Of course the Tranny/GM folks say bring it in so we can diagnose it for you... $$_^_$$ they say! Figured I'd try a few simple things before I'd let them to hack on it. Anyway today I did one major thing by replacing 1 gallon of the tranny fluid which puts me at 50% fresh fluid, definitely a noticeable difference and seems shifts fine now. The fluid I pulled was almost brown in color, versus the nice red/clear new stuff, pretty quick & cheap at $12/gal. Figured I'd do this once more but 6 quarts next time more times to get more fresh in it. I have a 1.5 gal vacuum pump which easily sucks it out in about 10minutes, then replaced it with new, I calculated that after the second flush, I'd be at 87% pure tranny fluid, if needed I’d do it once more with 6 more fresh it’ll be at 97%. Ya, I know I should drop the pan and replace the filter, but I don’t have the time and weather kind of sucks, figure I’d do it later this spring. Phase one, $12 bucks and a few minutes of my time and it seems to have done the trick. How I wish I had a :shades: manual transmission!
    Hope this helps.
  • My 2000 Grand Prix just started not going into drive. It shifts fine in all the other gears. Sometimes it goes into Drive but quickly goes back to 3rd. I have no error codes or check engine light. Did you resolve your problem? If so what did you do?

  • No i havent resolved it yet. I havent found anyone who can give me a answer on what it could be. Been to 4 different shops, they cant figure it out. They keep saying we can just replace the transmission but we are not sure thats the problem.
  • My 2000 SE was shifting hard after a newer tranny, new valve body and pressure sensor....more money than I wanted to put into the car...anyways it was still shifting hard. I had the diagnostic hooked back up and took it for a seems as though the torque convertor is sticking at times. My gas mileage sucks now. Anyone else have this problem?? Is it worth fixing??
  • my tranny just started overheating friday it has never done this before i thought it was the fact that i had barely any coolant in it so i filled that up and put some tranny fluid in it and it still overheats it overheated to 199 friday night. what would cause it to do this and what should the normal temp be?
  • That is a pretty common problem the grand prix. From what i read anyway.
    Take it to the shop. Let them look it over. Warning its not cheap to fix.
  • cnwcnw Posts: 105
    What was your engine temp when the trans was at 199? Trans should be approx same since they use the same radiator.
  • I also have a 2001 Pontaic Grand Prix that will not go into overdrive I took it to the shop today and they said it was a front hub assembly, has anyone heard of this? As far as the windows I have had nothing but trouble with them I have paid about $800.00 to replace two window motors and now another one has gone.
  • dbbacherdbbacher Posts: 1
    I am having the some problem with my 2001 Grand Prix. I took it to a transmission shop yesterday they told me that my torch converter was going bad. I was quoted a base price to fix it of $2300.
  • fatboifatboi Posts: 3
    i have an 01 gp se with a 3100 engine once in a while when its hot it starts to make like a whining noise and it begin to shift hard like crazy but when i turn off the engine lets say about a minute and turn it back on it goes back to normal. whats the problem??????????????????????
  • Hi, I have a 1995 Pontiac Grand Prix and it shifts hard from 1st to 2nd gear. Im not much of a car mechanic i was hoping u could help me out. Mabey like a tranny flush or somthing
  • tb98tb98 Posts: 1
    I have a 1998 Grand Prix SE with 271,000 miles and until last Friday I had the most basic knowledge of transmissions. As I was accelerating from 45 - 50mph my car lurched, started making a loud whining noise and wouldn't shift into 4th gear. I was told everything from the torque converter to solenoids to replacement as possible problems/solutions. I also pulled a PO742 code: torque converter stuck on. I found if I drove in D my car had a top speed of 35mph - anything over that produced the whining noise, and had the tach hitting 3,000 when accelerating. Starting off in 3 and leaving it there I can drive like a normal person and it doesn't wind out the tach or make the whining noise, it just doesn't shift into overdrive. It's not a fix, but it helps while I get the money together to replace the trans, as at 271,000 miles this makes the most sense for me. In my search for answers I found this site, which has amazing people and information, thank you to everyone else who has posted :) I also found another site that shines a light onto all of our 4T65E transmission problems:

    I hope this helps someone out there, thanks again.
  • abyers1abyers1 Posts: 1
    I am having the exact same problem and I'm not about to get everything under the hood replaced just to have it continue. I've had a few minor things done and none of that has helped. No mechanic has been able to tell me for sure what the problem is and since it is only an intermittent problem I have let it go on for over a year. I was just getting worried that it might eventually cause real damage so I googled the symptoms and found this sight.

    Check out message # 63, 67 and others near those in this same forum. It's all about the same issues we have and they say a PCM software update from the dealership will solve the problem for about $40! But that finding a dealership who will do it is tricky. Also they had GTs so I don't know if that matters.

    I called Pontiac customer service and they were completely unhelpful. I'm taking my car to the dealership on Monday so I'll give an update if there is one to give.
  • grwatchergrwatcher Posts: 3
    To montana_cat: what Pontiac do you have?

    My GP has been for 2 months bucking/hesitating when I'm going 45-70 mph up even a slight hill, randomly. No computer codes. I've had it tuned & the fuel system flushed but no help. Took it to a major GM dealer in Winston-Salem & they could get it to do it only once. Based on that the mechanic guesses that it's the torque converter. I went back today and asked them to update the PCM software. I was told it was up to date, they called Detroit. I looked the service manager in the eye and said, "So you are telling me that the software they installed in 1999 is the latest there is for my car?" and he answered yes. He then said that the only update is for the 97 GP (I printed message #63 & gave it to him so I think that's where he got that line). :cry: All this cost me $79. Here's what my invoice says:
    called GM Tac. Case number 109*****. Advised car has latest calibration in vehicle. Calibration number is 9384244.

    I have the full case # & the name of the person he talked to. I also know how customer support at large corporations works. And I feel the sm wanted to just get rid of me & my problem. I want to check this out. I have to keep this car for another 2 years. I have all the maintenance done, had the tran flushed at 58k. Except for this problem, it's a sweet ride and I'm in the car a lot for work.

    Any suggestions? These guys will not lie saying the tran has been rebuilt, I know that. And I know no one in the business.
  • grwatcher,

    I have a 1999 Grand Prix GT. I wish you all the luck in the world in getting yours fixed. I agree about the sweet ride and great car - other than this transmission.

    They updated my PCM finally after I had taken my car to the dealer 12 times (no joke) and spent $1,500. I was told by the service manager and mechanic who had worked on my car most of the 12 times that he (the mechanic) called Detroit and they put a new, unreleased version of the program on my car. I have not had a problem since.

    So, there was a new version in late 06/early 07. But I wonder if it was ever officially released? Others have come on here after my posts and said that their dealerships tell them their software is up to date, but they still have problems. So, I don't think they have the same version that I now have.

    Oh, and the torque converter/solenoid cost me $850 and still didn't fix the car. I actually had the solenoid changed three years prior when the car was doing the same thing for $400. Then I had to have the rear main seal fixed because they messed it up changing the solenoid. So, I've had two solenoids, a torque converter --- then the service manager decided it wasn't the transmission even though it was --- and tried a bunch of other stuff. It was the post that I printed off from here that finally got mine fixed.

    I wish I could help you more. I guess my advice would be to try another dealership and see if they are more cooperative. I'm thinking that I got lucky and the mechanic got ahold of the right person when he called Detroit. If you have any other questions, feel free to ask. I'll try to help as much as I can.
  • My car a 1997 Pontiac Grand Prix SE 3800, when started and in drive will not move like its in neutral. It has shifted just fine up until about a week ago when checking the fluids i noticed that the tran fluid was low, I put the correct type of fluid and did not over fill it (I might have caught it so late?) . After that time when i would be driving for an extend period it would what i would call shift like someone who is learning to drive a manual.
  • pohodarpohodar Posts: 4
    Just bought 99 grand prix GT and i like it a lot.....BUT i just noticed that when im driving on the highway my RPMs are pretty hight....70 mph little over 3000 which is way too much for overdrive....also if i put it in 3 the rpms are very similar....another simptom is when you let of the gas the rpms drop to seems like it shift in neutral and when you hit the gas again it has to come up to 3000 for it to start going again....
    other than that the car shift and drive smooth and fast....
    Someone please tell me there is a cheap way to fix it....
    PS Love this site very informational.....:o))))
  • redclownnredclownn Posts: 2
    Hey guys/gals. I bought a 2000 GP GT with 141k a couple weeks ago. I recently went on a small road trip (about 60 miles) and my friend and I noticed that my car was running high RPMs. Around 4000 @ 80mph. My friend said that my overdrive might be out. Luckily I got a 18/18000 power train warranty with the car. I'm going to bring it into the shop tomorrow. I've been reading on here that a few have mentioned a hub assembly. To me I don't think that would cause the overdrive to go out. I'll let you all know what they find out tomorrow, if anything.
  • pohodarpohodar Posts: 4
    I have a GP GT 99 and my overdrive is also not working i am very interested in what you find out....I am taking my car to a pontiac place hoping its not gonna be too expensive....:o))) :shades:
  • redclownnredclownn Posts: 2
    I found this website that might help a lot of us that have the 4T65E transmission. I list a lot of problems people have listed on here.

    4T65E Transmission Info..

    Some things it lists are:
    Neutrals at stops, Shudders on take off
    Tach bounces up and down a few hundered rpm while cruising in lockup
    No 4th Gear
    and a few others.

    Hope this helps a lot of us! :)
  • have a Pontiac GrandPrix 1995 SE V6 3.1 VIN M. The EGR is leaking exhaust air through EGR valves. I changed the EGR with 2 used one and got the same issue. I installed a new one and I got the same issue. This hot air is causing cables and vacuum lines to burn. I changed the EGR gasket too and is not leaking hot air at the gasket. I verified any burned cables and there are no cables burned.

    I changed the vacuum lines that goes to MAP sensor, PCV, and intake air tube.

    This occurs when I push the throttle up to 1500 - 2000 rpms. This issue is annoying. Please help. I am thinking to change the TPS and the MAP sensors because these sensors usually controls the EGR but I am not sure. :cry:
  • pohodarpohodar Posts: 4
    @!#$#%$% not very happy about that but works fine now...
  • gp1998gp1998 Posts: 1
    I have the same issues with my GP - now progressed to failing in Drive, 3 and 2 last week and now this morning Drive and 3 acting like reverse and 2 working...and locks not working except manually...

    Did you come to any solution?
  • what did they find out? (why wasn't it going to overdrive?)
  • I had a similar problem...come to find out my shift cable was the wrong might wanna check out if your shift cable is connected properly.
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