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GTP Trans won't shift to 4th after hill

SliceTheRice

SliceTheRice

New member
This has happened to me 2 or 3 times in the past 2 or 3 years, but it's starting to cause me some concern.
Today I was driving up a large hill and the car shifted into 3rd and I was able to maintain 65 MPH at about 3K RPMs the whole way up, no prob. But when I got to the top of the hill the car would not shift up and the RPMs would stay at 3K while going 65 on level ground. I tried slowing down by 10 MPH or so, but it wouldn't shift. Finally when I came to a stop light and then resumed back up to speed the trans acted normally. I checked the tranny fluid when I got home and it doesn't seem burnt and is a healthy reddish pinkish color at the correct level.

What would cause the car to stay stuck in 3rd like that?
 


if it only happened 2-3 times in 2-3 years then whats the worry about. I am guessing that the computer is confused at what you are doing and when it levels out it does not go back to noraml until you downshift enough times. Thats just a guess.
 
Well that's the first problem.

The second problem that I've been dealing with everyday since I can remember is the weird oscillating RPMs issue when it wants to shift out of fourth. It's like it wants to but just can't make up it's mind. The engine starts bogging really bad and the RPMs just start going up and down and the car starts lightly lunging. At that point, if you just give it more gas, it will shift down to 3rd and run just fine. And this is actually going in or out of forth gear. I've actually had a few shops take a look at this and no one has been able to pin point it. I had a CAI on a while ago and one trans guy said that he thought it might be causing engine load problems (so I took it off and left it that way - didn't fix anything). I took him for a ride along while he had his trans computer plugged in and monitored the shifts. He also said the trans had no codes stored either. I did have one friend suggest leaving the battery unplugged over-night to reset the computer and that actually temporarily fixed the oscillated RPM's issue, but it slowly came back and then just gets worse and worse. I just try to avoid the situation now by just giving the car enough gas to that it doesn't have to try and decide to shift- I just make it shift.

...I hate transmissions.
 
lol @ the trans guy saying a CAI would affect it... if indeed 4th clutch is gettin ready to go... its time for rebuild or replace.
 


On my old 97 GTP it would do what you are saying at around 45-53 mph. It is like the computer cant decide what its want to do. I would just put the cruise on at 50 so it didnt have to do that. I drove my like that for a year befor the motor went.
 
Part of your problem is that you still might be going up hill even though it doesn't look like it, your just not going as steep. And with the new transmissions it learns shifting patterns if your driving like a teenager it will shift like a teenager if your driving like your 98 year old grandma it will shift like a 98 year old grandma. I wouldn't worry about it unless your cruising at 60 and it's staying in 3rd all the time.
 
ckrummy said:
Part of your problem is that you still might be going up hill even though it doesn't look like it, your just not going as steep.
Click to expand...

Well after you get to the top there's a good portion where you're going down hill and actually picking up speed with no foot on the gas. Even then it stayed locked in 4rd. You'd press on the gas and the RPMs would just shoot up without any real change in your speed (because you're already going so fast). It was almost like the car was in neutral, but I could feel a tiny bit of response so I know it wasn't. Like I said, it wasn't until I stopped at a light that the trans started acting normally again.

I wonder if the computer is to blame for the going in and out of 4th gear indecision issue. I'm getting a new tuned PCM soon and that would just be sweet if that problem went away with a new computer. :th_thumbsup-wink: I won't be holding my breath too much though.
 
Well it did it again yesterday. Exact same thing and exact same hill.

I don't plan on keeping this car forever (but I do want to hang on to her for a few more years) and I don't plan on making it a serious track car, but given how crappy these stock trannies are, what do you guys recommend once this one finally does crap out? Should I have a rebuild done or should I get a new one? Give me some ideas/thoughts...
 
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A new one will just give you a new one with the same problems waiting to happen. Get a rebuild from trannyman at Triple Edge Performance. He fixes all the common problems these trannies have with improved parts.
 


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