Why does my car overheat on hills?


Asked by May 27, 2017 at 11:42 AM about the 2003 Buick Century

Question type: Maintenance & Repair

My Buick has a new radiator and A/C system. I recently took a trip to Northern Az. We had to climb an incline leaving the valley, and on the way back down. My car got so hot that the temp light came on. What would make it do this suddenly? I checked the radiator, when it cooled off, and it was full.

4 Answers


does it now over heat in normal conditions ? pull the oil fill cap and look on the bottom , what does the exhaust look like ? let us know what you see .

1 of 1 people found this helpful.

You may just need a good cooling system flush. Your engine was working harder than usual and if your cooling system is not 100% it may not have been up to the task. If that doesn't solve the problem have the coolant tested for exhaust gases. The 3.1 is known for blowing head gaskets. HTH. -Jim

1 of 1 people found this helpful.

When I had the A/C installed, the man worked hard cleaning out the system. It seems that before I bought it in 2011, someone had put "Stop Leak" in it. There was metal everywhere. He said my heater doesn't work, because that system is probably all gunked up, too. It does not get hot around town. That's also the 1st time I've ever taken it up that hill.

1 of 1 people found this helpful.

Those stop leak products cause more problems than they solve. It's too bad a previous owner put it in there. Try flushing out the cooling system using a chemical cleaner. That may get the rest of the stop leak product out of there. As for the heater you may want to replace the heater core. Also, be sure all air is out of the cooling system. Your mechanic should have a tool to pull the cooling system down into a vacuum for refilling. HTH. -Jim

Your Answer


Looking for a Used Century in your area?

CarGurus has 590 nationwide Century listings starting at $2,500.


Buick Century Experts

  • #1
    John Saffrahn
  • #2
    Tom Demyan
  • #3
    John Pate
View All

Related Models For Sale

Used Buick LeSabre
8 Great Deals out of 1,241 listings starting at $799
Used Buick Regal
105 Great Deals out of 4,267 listings starting at $3,498
Used Chevrolet Impala
395 Great Deals out of 27,759 listings starting at $1,499
Used Buick Park Avenue
294 listings starting at $4,500
Used Chevrolet Malibu
655 Great Deals out of 48,707 listings starting at $1,500
Used Toyota Camry
878 Great Deals out of 72,654 listings starting at $1,400
Used Honda Accord
607 Great Deals out of 92,577 listings starting at $1,495
Used Chevrolet Monte Carlo
962 listings starting at $3,300
Used Honda Civic
389 Great Deals out of 51,733 listings starting at $1,200
Used Ford Taurus
156 Great Deals out of 15,535 listings starting at $1,900
Used Pontiac Grand Prix
1,943 listings starting at $3,000

Used Cars For Sale

2004 Buick Century For Sale
62 listings starting at $2,500

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.