Pontiac Problem

GIMMEWHATEVER

MEMBER
1997 PONTIAC GRAND PRIX
6 CYL
FWD
AUTOMATIC
89,000 MILES

Hi I have a 1997 Pontiac Grand Prix GT. I put a little less than 30,000 miles on it since I bought it in 2002. But when I first bought it the transmission went a few days after so the dealer rebuilt the tranny. After that it sat for 3 years. And now that I got it running 2 years ago Ive been having a problem. When Im on the highway or high speed limit road around 40mph the rpms drop to 2000 to 2500 and will just stay there until I floor the gas pedal or let off then back on the gas. Once I do that the rpms go back up and its fine but itll continue doing that from 40 mph and up. I replaced spark plugs and wires, alternator, belts and I had the transmission fluid flushed. I would really appreciate it if you could give me some insight on what it could be as I am not able to afford a new car and this is my only means of transportation. Thank you very much for your time and whatever answer you can give me.

6 Replies

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

All you can do is have it scaned and go from there, but if I was to quess I would have to say it was a bad shift solnoid. If spelled right lol.I dont think it has a kick down cable?If it does then its out of adjust.

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Wednesday, December 15th, 2010 AT 2:29 AM

BMRFIXIT

MECHANIC
19,053 POSTS

Let me ask if you have a check engine light on?
And if so 1st should get the codes
most local part stores and local shops will scan it for free

also you may want to check catalytic converter and exhaust back pressure

let me know

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Wednesday, December 15th, 2010 AT 2:31 AM

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

Also thinking a lockup solnoid. And yes this would make the check eng light come on, like I said it needs to be scaned.

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Friday, December 17th, 2010 AT 2:46 AM

GIMMEWHATEVER

MEMBER
5 POSTS

There is no check engine light on. I fixed the exhaust and it runs smoother not as loud but it didnt fix the problem. From 1mph to 40mph theres no problem. But as soon as I go above 40mph the rpms bog down to around 2000 and stay there and the higher speeds around 70 mph it bogs down to 1500rpm. I checked the vacuum and its fine I think its something inside the transmission. But then again theres no check light on. What might you suggest? I checked underneath the car and theres no real sign of any leaks. Would the transmission filter be clogged and causing this problem? And if I had a shift solenoid problem wouldnt it cause no shifting?

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Tuesday, December 21st, 2010 AT 12:59 AM

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

Yes it might, its kind of hard to fix online, with a problem like that I would have to drive it to realy see whats going on and we both know I cant do that, sorry. It might be a running problem with the engine making it have a loss of power.