Skip the auto shop - Our mechanics make house calls

Q: When heat is on temperature gauge goes towards cold. When heat is off it goes back to being in the middle. 2001 Buick Regal

asked by on

When I put on the heat when the engine is warmed up the temperature gauge goes from in the middle of cold and hot , down one quarter towards cold. When I turn off the heat it slowly rises back to being in the middle of cold and hot.I took the car to Firestone 4 months ago to change the coolant and I remember seeing red or pink fluid. This car takes Dexcool which I'm told is orange. Is it possible the shop put in Toyota fluid which I've been told is red and if so am I making the situation worse? Do I need to have the fluid flushed again? Do I have air in the radiator? Do I need a thermostat? Thank you.

My car has 63834 miles.
My car has an automatic transmission.

Hi there - the temperature gauge behavior you describe would indicate that you need a new thermostat. The thermostat should keep engine temperature within a close range - close to the center of the gauge from a visual point of view. The fact that turning on the heater allows the engine to cool down indicates that the thermostat is not doing it’s job. It’s impossible to know what the service center put in your cooling system prior, but you are correct - Dexcool, the GM-recommended coolant, has an orange tint to it, and should be used in your engine. I would recommend having your thermostat replaced by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, replace your thermostat, refill your cooling system, and bleed it. Your temperature gauge should remain centered from then on, and you can be sure the correct coolant will then be in your engine.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. When heat is on temperature gauge goes towards cold. When heat is off it goes back to being in the middle. 2001 Buick Regal

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Replaced rt.& Left Rotors and brake pads. Also Rt. hub. the problem is ABS & brake light still come on. Does this have be reset ? 2004 Buick Ranier

Hello - the short answer is "Yes", the ABS problem code needs to be cleared with an appropriate Scan/Reset tool. This also begs the question "Was the ABS specific code read when the ABS light first came on, so that...

Q: RPM'S are slipping and tranmission knocks, also the brake pedal goes to floor

Hello. It sounds like you have a very serious transmission issue. You're only at a 100,000 miles so it shouldn't be risky to do a transmission fluid exchange. Another 20,000 miles or so then it would be very risky. I...

Q: Car shakes and turns off

Hello. There are many factors that can cause a car to stall upon start up. You could be experiencing a fuel supply problem or a fault with a sensor in the engine management system. The first step with any drivability...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.