Skip the auto shop - Our mechanics make house calls

Q: Temp gauge goes up and down

asked by on

The temp gauge in my car goes up and down. I changed the thermostat, radiator hose, and water pump. It doesn't overheat, but the gauge moves over toward the red and then moves back to cool side. I was told my temperature sensor might be out or bad.

Hi there. The temperature sensor is the device used to determine the estimated engine coolant temperature reading. The sensor itself is not always perfect. This device sends a signal to the computer and in some cases, the instrument cluster as well. A loose connection or malfunctioning sensor can sway the values and show an improper reading. If you need further assistance, I recommend you have a certified technician, like one from YourMechanic, inspect the electrical components to make sure all the connections are good and replace any failing parts

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!
  1. Home
  2. Questions
  3. Temp gauge goes up and down

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: Overheating and cutting off while driving

If the engine is overheating to the point where it's shutting off and blowning coolant out of the tailpipe, you have a bad situation. A failed distributor or cracked coil may cause the engine to stall when warmed up. Consider...

Q: Can an almost new tire have dry rot?

Tires can dry rot pretty quick in dry hot climates but should last at least 3 or 4 years before needing to be replaced. If tires have dry rot then you will see small hairline cracks in the rubber either...

Q: Car won't start after battery replaced

Engine starting on a hybrid is more complicated than a gasoline car. The starter is also the alternator and a drive motor. It is located in the bell housing in between the engine and transmission. There’s a lot more computer...

Related articles

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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.