Skip the auto shop - Our mechanics make house calls

Q: Temperature guage stays on cool, heat inside is not very warm

asked by on

While driving with heat on, I noticed that it wasn't heating like it should inside the car, not warm enough. Also noticed the temp guage never raised off the cold on a 10 mile trip. Could this be a sensor problem? Or more likely the thermostat needs to be replaced?

My car has 190000 miles.
My car has an automatic transmission.

If your heater is not getting warm enough and the engine is not reaching operating temperature for a long time then your engine most likely has a thermostat that is stuck open. A stuck open thermostat can be verified by a mechanic like one from YourMechanic. The mechanic will start and run the engine to check the cooling system to see if the thermostat is causing the engine to run too cold. If it is stuck open then it will cause the heater to not get warm enough and the engine running too cold will get poor fuel mileage. Have the thermostat tested and replaced then run the engine to see if the engine comes to operating temperature within about 3 minutes running the engine at 1500 to 2000 rpm. Then recheck the heater operation and it should work correctly.

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. Temperature guage stays on cool, heat inside is not very warm

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: Bad mileage & strong gas smell in dipstick/oil pan - 1996 Nissan 300ZX

Okay, so usually the answer to problems are usually hidden in the fine details. The whole reason you started noticing a problem was the gas mileage. If this was my car, I would be thinking that I have a fuel...

Q: Is $2300 too much to pay to replace 2 cat converters for a 2007 Pathfinder?

Hello, thank you for writing in. Your particular make and model does utilize a catalytic converter on both sides of the engine. Catalytic converters are going to vary in price depending on the brand of replacement parts that you are...

Q: I bought a used vw beetle 2001. diag test came up with codes t0300 t0303 t0172 t0768 mechanic said he would charge 900.00 for the

Each of these codes are for different problems, and would need to be diagnosed. If you are low on coolant, then your misfire may be due to a blown head gasket and the first three codes. The last code, P0768,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...