Skip the auto shop - Our mechanics make house calls

Q: Stuck thermostat?

asked by on

When driving the temp climbs between 210- 245. may bounce between the two temps. Doesn't drop when driving. Heater blows hot than cold. Heater has always blown hot.All these signs just started this morning. Is this a common sigh of a bad thermostat

My car has 218000 miles.
My car has an automatic transmission.

From what you described, it potentially might be a few different things that may be wrong with your cooling system. As you may know, when the coolant is pumped through the radiator to the engine, some of this coolant is recirculated back through the heater core. Heated air from this is blown through the vents into the interior of your car. The fluctuation in temperature may be also caused by a faulty or stuck thermostat which may cause the erratic changes in temperature. This may also be caused by a clogged heater core or even heater core hose leaks. I would recommend having an expert from YourMechanic come to your home to diagnose and repair your cooling system.

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. Stuck thermostat?

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: How do I replace the air flow control door within the vents?

Hi...the absolute best, instruction by instruction, illustrated tutorial is in the GM Factory Shop Manual for the 1996 Jimmy and I checked quickly on Ebay and they are readily available. Due to the amount of detail, and inability to post...

Q: honda civic 2005 overheating intermittently fluids are full. what might cause this. thought it might be thermostat

A sticking thermostat could cause the overheating you are describing. The intermittent cabin heat might be due to the coolant boiling, at times, and the resulting air pockets block coolant flow to the heater core in the dash. Engine overheating...

Q: Have a prob with my front drive shaft jus not sure exactly

Hello. Thanks for writing in about your Dodge Dakota. You should have a mechanic come and check the problem for you. If you do have an issue with your front drive shaft, most problems with an axle CV joint is...

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...
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...