Skip the auto shop - Our mechanics make house calls

Q: thermostat?

asked by on

the temperature gauge goes up to the middle (straight up) once the car heats, then once I turn the fan on for the heat it backs down to the left and stops halfway between 100 and 210. Is this normal or does the thermostat need to be replaced?

My car has 213000 miles.
My car has an automatic transmission.

A: It is not uncommon for the temperature gaug...

It is not uncommon for the temperature gauge to drop when the heater is switched on, especially in colder situations (below 40 degrees f). The thermostat should be able to control the engine temperature in a way that you should be able to still get hot air into the cabin when the heater is engaged. I usually suggest that as long as the heat coming into the cabin is sufficient to keep you warm, I wouldn’t normally worry about the lower temperature on the gauge. If the air coming out of the vents isn’t getting warm enough though, I would try changing the thermostat. If this is something that still worries you, and you feel that you could use a hand in diagnosing or repairing it, I would suggest consulting a certified mechanic, like those available at YourMechanic.com.

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!

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 bus is not starting.

It sounds like you may have a problem with your key. If the key is excessively worn it will not be able to unlock the ignition cylinder so you can turn the key. I would ask for help from one...

Q: Vehicle idling rough once warm

This might be due to a vacuum leak. Vacuum leaks are common in older vehicles because of the age of rubber lines, gaskets, etc. The vacuum leaks alter the air fuel mixture and as the engine tries to adjust it,...

Q: Heater not blowing hot air, only warm.

The most common causes of poor or no heat conditions would be (but not limited to) low coolant level, a restriction in the cooling system, faulty blend door actuator, or faulty heater control valve. I would recommend having the cooling...

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...
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...
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.