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.

A: Hi there - the temperature gauge behavior y...

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

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: My car has only misfired twice but idles perfectly. The Check Engine Light is also on - 2012 Buick Regal

Hi there. From the description you have provided, concerning your vehicle's Check Engine Light and two misfires, it is advisable that you get a second opinion. A timing chain problem would cause your vehicle to have a consistent drivability issue....

Q: Why does my car intermittently not crank over. 2003 Buick Regal

Hello. This can be caused by a few different issues. If the vehicle is equipped with an aftermarket alarm system then that can cause this. If the vehicle is only equipped with the factory alarm system then it is either...

Q: 2001 Chevy Blazer distributor install.. it is at top dead center and the rotor lines up with the 6 but is not seated all the way.

If you are using the marks on the harmonic balancer to find TDC, occasionally the balancer will have shifted (the rubber bond breaks) causing the timing mark to be some degrees off. Consequently, the crankshaft is not really at TDC...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.