Engine Overheating


Asked by acturner Sep 23, 2007 at 06:27 PM about the 1998 Pontiac Grand Prix 4 Dr GTP Supercharged Sedan

Question type: Maintenance & Repair

I have changed the thermostat and the water pump on a 1998 Pontiac Grand Prix GTP.  The temp needle still goes in the red...any suggestions?

14 Answers


you allmost deffinetly have a blowen head gasket do a compresion test. "notorios problem on almost all turbo charged and supercharged engins"

3 out of 3 people think this is helpful.

This might be a dumb question, but did you change the coolant when you did this work?


Yes we did. We fixed it. Thanks

4 out of 4 people think this is helpful.

what did you do to fix the problem?

7 out of 7 people think this is helpful.

I have the same car and same problem 98 grand prix GTP 3.8 l changed the head gaskets intake had a head shop check the heads and intake new thermostat and coolant tempature sensor. Still goes to RED?? is there a way to check the water pump? What else could it be?

9 out of 9 people think this is helpful.
Michael McGrail

I am curious why nobody ever changes the radiator cap first. Makes no sense to me. A $3 part that 9 times out of ten is always the problem.

5 out of 5 people think this is helpful.

i think you need to try intake gaskets they are famous for going out or even your radiator could be plugged reducing coolant flow

1 out of 1 people think this is helpful.

radiator could be plugged

1 out of 1 people think this is helpful.

I have 98 grand prix also running hot what should I do???

3 out of 3 people think this is helpful.
Rob Pfrommer

lol wow i joined the club today 2 changed everything water pump all new hoses thermostat,new radiator cap new coolant and still running hot any 1 find the fix yet

4 out of 4 people think this is helpful.
Michael McGrail

Rob, what temperature thermostat did you use? Also, have you inspected the system for coolant leaks?


The Pontiac V6 has to have the air bled out to cool properly. If you are looking for a overheating cure, bleed the air out. --- http://www.gaownersclub.com/forum/faq.php? faq=maint_repair#faq_cooling_serv

7 out of 7 people think this is helpful.

If your Pontiac is overheating, first make sure the electric fans are coming on. This flaw should have been a recall. Its a good idea to change the thermostat and temp sender unit. Cheap fix. Make sure you bleed the system. 2000 GP 3.1 has 2 bleeders. If the car only over heats while sitting in traffic, most likely the fans aren't coming on. Pull over and pop the hood, check the fans. The temp sender unit tells the ECM module to turn on the fans. So it could be either. These cars are known for head gasket issues. But really its the cooling system that causes over heating which causes head gasket failure. So don't ever let it get hot enough to get into the red. Turning on the AC turns on the engine cooling fans on a 2000 Grand Prix, and probably other models.

6 out of 6 people think this is helpful.

How do I Figure out if I find Out if iI have a blown head gasket on 77 pontanic grand prix .sj with 400 cu in Engine

3 out of 3 people think this is helpful.

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