Temperature fluctuating

2007 PONTIAC GRAND PRIX

186,000 MILES • 3.8L • 6 CYL • TURBO • 2WD • AUTOMATIC

SBENNETT6585

MEMBER
12 POSTS

I have the car listed above supercharged. Lately the temperature gauge has been fluctuating from about three quarters all the way down to almost all the way low. The other day after driving on the highway for thirty minutes when we took the exit and come into town at the stoplight the temperature was reading all the way at the low position and the heater was barely warm. I am stumped. Please help. thank you.

Mar 4, 2019 at 12:22 PM

SCGRANTURISMO

✓Experienced Mechanic
4,897 POSTS

Hello,

This could be a problem with your thermostat sticking. Usually when a thermostat exhibits symptoms like these, it's best to replace it. They're inexpensive and if it decides to stick closed and you don't catch it, you could overheat your engine and do major damage to it. I have included a few links below for you to check out.

https://www.2carpros.com/articles/how-an-engine-thermostat-works
https://www.2carpros.com/articles/replace-thermostat

I have also included directions on how to replace your vehicle's specific thermostat in the diagrams below.

Thanks,
Alex
2CarPros

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