I have a 97 pontiac grand prix gtp and the transmission makes a whinning noise in third gear. when i am going like thirty five if i let off the gas the rpms go down but when i go to accelerate the rpms go up to like 2000 or 2500 before it starts pulling and i can rev it between 1000 and 2000 rpms and it doesn;t pull at all but when the car shifts into 4th it stops whinning and it pulls fine accept when i get up to like 80 sometimes it wants to shift down into third when i barely push on the accelerator. I would like to know whats wrong and what should be done like transmission rebuild, bearings bad, new drive belt, new torque converter etc.

Archie Ferrarini

• 869 Answers
• Posted on Jun 11, 2008

SOURCE: monte carlo

You need to rebuild the transmission,it's over heating. May want to check your transmission cooler first .
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SOURCE: 94 Nissan Altima accelerator problems

check your throttle position sensor

SOURCE: no acceleration

I had the same problem with one exception. It would rev higher than 3500 but the higher it revved the more it bogged. I had the catalytic converter replaced. I thought I bought a new car. Acceleration is just like new. It was easy enough to test. My mechanic cut a hole in the exhaust pipe in front of the catalytic converter. It sounded like a truck but the acceleration difference was immediate. Easy diagnosis.

The car is hard to shift because the more you press on the accelerator the more the computer for the transmission won't let it shift. Which in turn causes the car to bog more sending more unburned fuel into the catalytic converter. Which in turn causes more carbon build up and more back pressure. Vicious cycle. It will only get worse.

My thermostat caused the entire problem. Thermostat was stuck open, engine never got to operating temp most days. Car burned rich. Bad gas mileage. A lot of unspent fuel being dumped into the converter. Probably have some underlying cause that needs to be addressed. Bad plugs, wires, coil, fuel filter.

SOURCE: i am replacing intake gasket on my 98 pontiac

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c15280217c80

Try this not sure.

SOURCE: Location of mass air flow sensor, 2000 Grand Prix GTP

3.1 or 3.8 motor, mass air flow is in the fresh air (goes from air cleaner to engine)