Grand prix heat off and on also, drinking coolant?

20

Asked by Jan 21, 2016 at 09:55 PM about the 2002 Pontiac Grand Prix SE

Question type: Maintenance & Repair

02 grand prix 250k miles. Really weird situation here, what it does is the
gauge will act normally and produce heat normally. All of a sudden it flies
up and down slowly almost overheats but doesnt. Then the gauge will
come back down all the while me having absolutely no heat. What ive done
before is add coolant (dexcool) And it will stop, it will produce heat, and act
normally for about two weeks. Now ive noticed no physical spiils on the
ground and the oil isnt milky. It needs changed but isnt milky. any ideas???
im at a loss here...

3 Answers

74,195

Wildly fluctuating coolant temperatures would indicate to me that you have a bad thermostat.

1 of 1 people found this helpful.
98,385

When it starts the fluxuations is when it is running low on coolant, the most probable cause is a blown headgasket especially with that kind of mileage. I would recommend performing a block test, that will confirm that exhaust gases are present in the cooling system.

1 of 1 people found this helpful.
69,315

Since this is a SE model I'm assuming you have the 3.1L V6. They blow head gaskets. But before you condemn the motor, at 250,000 miles the head gaskets should have been done already, long ago. With the engine cold pressure test the cooling system. You may have a seeping hose, water pump, radiator, or heater core. The cooling system should hold 15 PSI for a minimum of 15 minutes. If not it's leaking somewhere. Also pressure test the radiator cap. It may not be holding pressure. That can cause a "sneaky" leak as well. HTH. -Jim

Your Answer

Grand Prix

Looking for a Used Grand Prix in your area?

CarGurus has 2,730 nationwide Grand Prix listings starting at $1,200.

ZIP:

Pontiac Grand Prix Experts

  • #1
    Js08016
    Reputation
    4,370
  • #2
    Tom Demyan
    Reputation
    2,970
  • #3
    munron
    Reputation
    2,350
View All

Related Models For Sale

Used Chevrolet Impala
590 Great Deals out of 34,659 listings starting at $1,000
Used Pontiac Bonneville
515 listings starting at $1,799
Used Chevrolet Monte Carlo
11 Great Deals out of 1,353 listings starting at $995
Used Pontiac Grand Am
1,091 listings starting at $1,599
Used Ford Mustang
759 Great Deals out of 42,755 listings starting at $1,300
Used Chevrolet Camaro
422 Great Deals out of 31,785 listings starting at $2,395
Used Chevrolet Malibu
1,235 Great Deals out of 78,093 listings starting at $1,500
Used Pontiac Firebird
12 Great Deals out of 814 listings starting at $1,900
Used Honda Accord
1,019 Great Deals out of 62,741 listings starting at $999

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
11 Great Deals out of 371 listings starting at $1,200
2007 Pontiac Grand Prix For Sale
11 Great Deals out of 365 listings starting at $1,350
2006 Pontiac Grand Prix For Sale
9 Great Deals out of 463 listings starting at $1,800
2005 Pontiac Grand Prix For Sale
3 Great Deals out of 356 listings starting at $2,350

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.