1998 Pontiac Grand Prix GTP Supercharge from North America - Comments

1999 GTP would not fire, cranked, but no start, would also quit all of a sudden while driving, or while stopped at a light, was the mass air flow, found a reputable place to diagnose, they also had a 20% off summer special coupon, nice, the part was just about as much as I found it online, about $215, so I figured it included labor also, seems to have fixed the problem for now, in case anyone else has the same problem, If you know it is the mass air flow, it would be easy to fix yourself, located in the air intake line, plug in, I'm sure there are better prices but the one I looked up was between $150 and $200, so the $215 was not bad and it was an emergency situation, It could have been fuel pump/sending unit but the supercharger fired when trying to start with gas pedal to the floor, hope this helps someone,

I own a '98 Grand Prix GT 3.8L it has been a great car 231,200 miles. Stuck some money in it, but it sure beats a car payment. I have had the tranny side cover and seal replaced (warr) 34,000m, rear crankshaft seal r&r (warr) 55,000m, rear seal again 97,000m $500, alternator 120,000m $120 I did r&r, drivers door window motor/cable $95 I did r&r, rear seal again 162,000m $500, sway bar/boot kit/lower balljoint 190,000 $535, starter 220,000m $164 I did r&r, water pump 226,500m $40 I did r&r. I love this car, it still get 28mpg, runs great. Thinking about doing the struts (originals) cause it rides rough and I can do it myself. So I've stuck in about $2000 maybe a little more if you count all wearable items, but it sure beat new car payments.

Well, you could have driven the car to auto zone, checkers, pep boys, or o-reily, and they will hook a scan tool up to your aldl terminal and find the problem for FREE!! And you could have replaced your MAF sensor yourself for half the price.

For future reference; if your check engine light comes on or any light does that, you'll SAVE A FISTFULL OF DOLLARS!!

I'm in the same boat with a 2001 Bonny 3.8;

16th Jul 2007, 12:54

To the person that posted on June 14th - about the TCS light going off and the Tac dropping to Zero - Engine sputters a little and then resumes just fine.

What did you find out?? Would love to know! I have had this car in 2 times to get this fixed and they have "fixed" 2 other things, but the issue is still happening.

Service engine light goes on now - and the code they say is a Crank shaft sensor - they fixed that and code went away for about 2 days. If anyone has an idea I would love to know. Want this car to last another year. Mine is a 99 GTP and has been pretty good to me so far.

I own a 1998 Grand prix GTP and absolutely love it to death. Which is where it is slowly heading due to all the minor problems mounting to major ones. But anyways, I finally did my plugs and wires at 165,000 miles. The ones on the front of the engine were a snap, but the ones on the back were a little challenging. I still can't get the last one (right next to the oxygen sensor, cylinder # 5,I think) replaced due to poor access to it. Does anybody have any tips as to access it, pull the wire, and change the plug and wire out. Do I have to come from underneath??? Any info would be very helpful. Thank you very much.

I have an 1999 GTP and it has 137,000 miles and I have recently noticed an unusual whining noise coming from the transmission. Has anyone ever had that noise? Besides that, it runs like a champ (since I replaced the supercharger).

I am working on a 99 gtp and it has intermittent starting. When it doesn't start, it is due to a no spark condition. I tried an ignition module, coils packs, and a crank position sensor. Still same problem. No codes, Scanner says cam sensor received, both 3x and 18x is being read. Does anyone know what the heck is going on or ever experienced this problem? It is not heat related because it may run fine for a week and then just cranks. Please let me know. Thanks.

A lot of people have negative issues with the Grand Prix. I am one of them. I am bitter, but overall I LOVE my car. I have a 98 4-door GTP. Thankfully, I talked my dealer into throwing in the 7/100K warranty. My car is now 9 years old.

The only real "pissy" issue I have is that I've replaced the window regulator and motor 11 times! Yes. That is ELEVEN times. The last one was just yesterday. The first 8 were under warranty. The last 3 I paid. Cost me over $1700 for all three so far. After 70K miles, the engine blew. Had to pay out of pocket for that. At 90K the supercharger blew. Had that replaced out of pocket. At 120K I replaced just about every moving part under the hood, including all the mounts. I now have 150K on it. It has been a GREAT car. There were other stuff I replaced, but it stuff that I expect for a 9 year old car with 150K miles. Regular repairs and replacement stuff for "wear and tear".

But I tell ya... those DARN window regulator with the PLASTIC CABLE RETAINER are freaking RETARDED! DARN GM for putting it out on market like that and DARN them for not recalling them and replacing them with a METAL cable retainer. HELL, if my $80 10-speed bike can have metal cable retainers (on the brake cables)... why not my $27,000 car?!?

Other than that... I love my Grand Prix. Rock On!

I'm an original owner of 1998 Grand Prix GTP. I do love this car. It has not been without problems, but it's done as well or better than my expectations. It now has 150,000 miles on the odo. Problems: The supercharger has been making noises at idle/no load for the last 20k miles or so. I won't bother fixing that item until it BREAKS. Windows were replaced 3 or 4 times under extended-warranty (like $1000 or so each time, ridiculous!), I'm hoping they don't break now that I'm out of warranty. I've replaced the A/C compressor and recently the condenser ($1,800 for both those jobs, total). The A/C capacity in Southern California does leave something to be desired, but I remember this always being the case. My volume knobs on the steering wheel have given up and I can't find replacement parts (that's stupid for what seems to be a part in demand). The LCD in my electro-chromatic mirror has melted away and no longer dims. She sometimes runs warm, but eventually cools down. I can smell oil, but she doesn't use any noticeable oil and I don't have any drips in the garage. The lens cover fell off my drivers side, I guess I'll order a new one. I've maintained this car well... tranny and radiator flushes, Mobil-1 5W30 since it was in diapers.

Do not just ignore the supercharger rumbling problem at idle and shut off, the part you more than likely need is the coupler. This part connects the nose drive shaft to the rotor shaft, and it is made of an oil soaked plastic so it wears out. The part is only $30 and if you can drain supercharger oil, untension both serpentine belts, and remove the alternator, you can do this yourself. You can take it to a dealership, but they will just tell you to replace the whole unit, the quote I received was $1970, which then went up to 2200 a few days later, go figure.

Anyway, my supercharger was doing the same thing, I refused the dealership work and purchased a rebuilt unit from PSE Superchargers, and had my mechanic put it in, when all was said and done it cost $750 for part and labor. When the unit was off my car I spun the pulley, there was no grinding at all, but when I wiggled it back and forth, there was space between the resistance, indicating the the coupler was bad, $140 to replace that, but I trusted the dealerships word for it. If you'd like to do it yourself check out this site http://www3.sympatico.ca/aepa/blowerinstall.html

A couple of people have posted about this, has anyone figured out what is going on? I have an 01 GTP with 143,000 and I have the same thing. It seems to happen when I'm under load and the rpm's are low. I've never had it happen under good acceleration.

About the TCS light going off and the Tac dropping to Zero - Engine sputters a little and then resumes just fine.

However mine will stay bogged out for a while, sometimes it will kick back in, but the tach is down for the count, other times I'm stuck on the side of the road for a min or 2 trying to get it to start. It cranks hard, but won't catch.

I have a 2000 GT with 138,000 miles that is doing the same thing with the tachometer dropping to zero and the "Trac Off" light coming on. As soon as the tachometer drops, the engine feels like it stops for a second an then resumes just fine. I have changed the plugs (twice), plug wires, fuel filter, and air filter. If anyone knows what the problem is, please let me know!!! Also, I agree that the plastic gears on the windows and the way they operate should be outlawed. This is an absolute joke. The senior executives at Pontiac that allowed this to go into production should have to replace all of them at their expense. I have replaced the back windows twice and now they are both not working again. Other than that I love my car. Eight years old, 138,000 miles and still get 28 mpg!!!

9:57.

I cannot say for sure, but your tachometer/"trac-off" problem sounds like an intermittent coil/coil-pack or ignition module problem. The tachometer gets its signal off the ignition coil (s), and one of the (several) methods by which traction control can work (not sure if it is this way on your Grand Prix or not) is by retarding the ignition timing when wheel slippage is detected. The fact that your "trac off" light is coming on at the same time your tachometer drops obviously shows the symptoms are linked. Now, assuming I could be somewhat on the right track with this, the question just becomes: is the traction control system fouling up the ignition system, or is the problem entirely with the ignition system and the "trac off" light is just a residual symptom. You will need a good mechanic to make that determination.

Unfortunately, since the problem is only occurring intermittently, it is probably going to be difficult to diagnose. But, if you are fortunate enough to get a mechanic that actually knows what he is doing, they might be able to find the problem. In my opinion, dealerships are often the worst place to take a car (I used to work at one), because they rush through the repairs like maniacs since they are on flat rate, and they do not know anything about troubleshooting beyond "hooking the car up to the computer" (which believe me, is not all it is cracked up to be).

But, for something potentially tough to diagnose like this, since it is intermittent and could present difficulty even to a very skilled mechanic, the dealership might be a good place to go, because they might have seen the problem before, and/or have a TSB out on the issue. In that case, they'll know exactly what the problem is without having to do any poking around.

I hope the above was somewhat helpful, but please know that it was all only a "reasonably" informed guess on my part. I used to know all of these systems backwards and forwards, but have been out of the game for a long time (11 years) now. If you do find out with certainty what the problem is/was, please post back; I would be curious to know. In any event, the Grand Prix is a very good car, and worth your while to keep in good shape.

Good luck.

I now own a 2001 Grand Prix Special Edition 2 dr, and I've never been more pleased with any other car. It's performance has been excellent, more than expected. The only problem I have with it is the speed control, it's locks up at 105 mph. I know you're not supposed to usually ask this, but, how do I disable that? It's the only problem I've had. I race it often and until recently was undefeated. The car I was racing with lost the acceleration race, but when it came to top speed, and eventually blew past me. Any suggestions?

That's strange. Mine doesn't cut out till about 124 and I have an 01 GTP special edition as well. Either way, I believe the only way to get past that is to change the ECM (i think). I think http://www.grandprixstore.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=PFYC&Category_Code=GP has the info you need.