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

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: Found oil in the water reservoir

Generally a pink milky fluid in the coolant indicates a leak between the transmission cooler and radiator. It is very possible the radiator has failed. Both the coolant system and transmission should be flushed to prevent cross contamination of fluids...

Q: My transmission hesitates.

This kind of reaction is often a sign of low transmission fluid or a faulty transmission control solenoid. As you know, automatic transmissions use pressurized hydraulic fluid to change gears. Every time a gear change is required, the car's computer...

Q: Dry grinding/starting noise when in gear

Hi there. Sounds as if the transmission is low on fluid or the transmission is worn and has roller bearings that are damaged. Check the transmission oil level and see if the fluid is low. The fluid should slightly run...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...