Skip the auto shop - Our mechanics make house calls

Q: What would cause the temperature gauge to go cold to hot then back to cold

asked by on

When driving the car the temperature gage goes to normal temp then to cold then back to normal or hot an this continues happens when you are driving it

My car has 1300000 miles.
My car has an automatic transmission.

The engine temperature is regulated by the thermostat opening and closing to maintain the engine temperature. The cooling fan clutch also will maintain the engine temperature to keep a controlled air flow across the radiator to maintain the engine temperature. In order to test the system you will need to monitor the coolant temperature and the operation of the cooling fan clutch to see if the clutch is staying engaged too long causing the cooling system to get too low before the fan clutch disengages. Replace the cooling fan clutch if clutch operation is erratic. Replace the thermostat if the thermostat lets engine temperature get above 200 degrees F before it opens fully. The thermostat should maintain the engine temperature at about 180 degrees F.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • What would cause the temperature gauge to go cold to hot then back to cold

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: After a radiator change, My car is shaking and emitting black smoke. What could be the cause? 2000 Volvo S80

Hello, your symptoms suggest a coolant temperature sensor failure, or wiring problem (cut wires or other "open circuit" issues). Changing the radiator may have caused the sensor to be bumped, or the wiring for this sensor to be damaged. An...

Q: Battery light is on durign acceleration or on bumpy roads

When the battery light comes on in vehicles it is due to the voltage falling below the required 12.6 volts. This voltage is required for all the vehicles' electrical systems to work properly. The most common causes of the battery...

Q: I have a leaking gasket on the timing chain cover.

Hi Ed: Depending on where you live, one of our mobile mechanics can complete a timing cover replacement. The best way to get a good price quote is to fill out this quote form and one of our sales professionals...

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...