Q: Heater core or thermostat

asked by on

Our jeep has been experiencing heating problems. It takes a while for the jeep to heat up. Not sure if the heater core is going bad or if the thermostat just needs to be replaced
My car has an automatic transmission.

If the engine temperature, as measured on the dash gauge, does not reaching the normal operating range within "roughly" 5 miles or so of driving, then a possibility is the cooling system thermostat is stuck open. Among other things, a stuck open thermostat will "somewhat" reduce the available heat to the cabin but, worse, will degrade the fuel efficiency of the engine. If the engine is reaching the normal operating temperature range within a reasonable interval, keeping in mind that cold weather will slightly increase that interval, and yet you have inadequate cabin heat, that could mean that the heater control valve is not fully open, the HVAC ducting is blocked, and/or the heater core is partially plugged. There are other possibilities, for example, check the engine coolant level (but, for safety reasons, only when the car is absolutely STONE COLD). If needed, you can request a thermostat replacement and/or a diagnostic on the inadequate cabin heat issue. Please let us know how we can best assist you further and, as well, if you have follow up questions.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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. Heater core or 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: not cranking over 1997 Jeep TJ

There are a couple possibilities. First, check and see if you're getting the constant power supply at the starter motor and if you're getting switched power at the starter solenoid that only shows up with the key in the crank...

Q: Heat/AC blower turns off and on

Hi there. Check the switch for any loose wires or shorts from the blower motor switch to the ignition switch. Check the condition of the wire connections for an corrosion and see if the wires are loose on the ground....

Q: I need to have a bad thermostat replaced.

Thermostats should not cause fluid to leak but will cause it to overheat. You should have your cooling system pressure tested to determine where the leak is coming from.

Related articles

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...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...