Reliability of the GP...

Hello all, just curious about the GP's...i am always hearing about a wide array of problems that have many people stumped. Is this a problematic car? I just bought a 99 GTP coupe, and it runs perfect..so far.

Is it more likely the problems i hear about come from poor maintenance?
Or could it just be beating on the car?

Welcome to AF!

The majority of the problems with the GP are with intake gaskets, wheel bearings and transmissions. The 3.8 Non-SC has issues with the intake manifold gaskets and bad plenums due to them being made of plastic material. Otherwise they are relatively reliable.

Wheel bearings are a common problem especially fronts and are expensive to replace since the ABS sensors are located inside the bearings.

Finally, the transmissions are an issue due to horsepower. The transmission in the GTP's is the heavy duty version and it can handle a lot although it will go in time. There are a few minor issues like supercharger rattle due to wear and bald tires due to excessive burnouts but that is to be expected. Otherwise the Grand Prix is a very reliable vehicle.
At least in my opinion!

Welcome to the forum.

It depends. If you got it used, you don't know the maintenance or abuse history, so anything could happen. The age of the car and mileage is also a factor. There are certain problem areas but overall the Grand Prix is a reliable car - IMO.

I have a '97.5 GTP (bought new) and still have the original engine, tranny and most of my original supercharger plus it's moderately modded and drag raced every season.









http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

Reliability is the reason why I bought a Grand Prix. I work at a Delco distributor and by the parts we sell, the Bonneville and Grand Prix are by far the most reliable GM cars out there. The problems GTPDad described are common to all GM cars with the 3800 (intakes) and ABS (hubs). I love my car and have no problems so far (knock on wood). I agree with Bnaylor and GTPdad, that the Grand Prix is a car with above average reliability. Welcome to the Forum.

Like stated by the other AF members , i agree...the GTP is a very reliable car...im pretty sure the 3800 motor has been rated to be one of the best. The tranny---4t65e-hd, has been know to have problems on these cars, and are very expensive to replace....before you decide to do any tranny maintanance i suggest consulting this forum first... a simple routine maintanance can ruin your tranny.....Like any car just dont beat on it constantly and take care of it....this doesnt mean you cant punch it out once in a while...enjoy the car...good luck!

a simple routine maintanance can ruin your tranny.....

Even a fluid change on the trans?



Anyways, the day I posted I almost bought the GTP, but went with a 99 GP GT instead. Took it to my mechanic friend who put it on the lift in his garage, and we took a look, nothing to report. Maybe a sway bar, has a small crack near the left bushing. Most fluids are very dirty, just replaced oil, coolant and brake fluid.

All speakers inside are either blown or so old they just plainly sound terrible. And the stock stereo volume knob gets louder when u try to lower the volume. (but steering touch controls work nicely)

Does'nt seem like it was maintained very well, but maybe i can turn it around before its too late.

And thanks for the warm welcome.