Skip the auto shop - Our mechanics make house calls

Q: Overheating issue, when heater is on its normal temp. but if heater is off it begins to overheats, until heater is turn on again.

asked by on

When driving, car over heats, but if I turn heater on, temperature eases back to normal, and is good to go unless I turn heat off again. Even when in idle doesn't run hot with heater on, but if heater is off it over heats.I put new water pump thermostat radiator degas bottle and cap heater control valve and bled it several times

My car has 200000 miles.
My car has an automatic transmission.

It sounds like your engine might have a restriction in the cooling system. If the cooling system has a restriction that prevents its flow, this will cause the engine to get hot. The heat is dissipated from the cooling system by means of the radiator.

When a restriction exists sometimes the radiator alone is not enough. The heater core is like a small radiator inside the dash and is also another means of dissipating the heat from the cooling system. So essentially when the heat is on you are introducing a second radiator into the system which will help to cool the engine down.

In order to get this fixed, consider YourMechanic, as one of our mobile technicians can come to your home or office to diagnose the overheating issue firsthand and help you make the necessary repairs.

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. Overheating issue, when heater is on its normal temp. but if heater is off it begins to overheats, until heater is turn on again.

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 can my power steering leak all of a sudden when it wasn't driving for 30 days?

Hey there. This suggests your power steering pump may be failing or you have a leak elsewhere in one of the power steering lines. The power steering system operates on very high pressurized hydraulic pressure (in some cases as much...

Q: Battery light just came on. What could it mean? Is it safe to drive?

This may be a sign of a weak battery, a failing voltage regulator or failing alternator. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while...

Q: Temperature gadget goes up while in traffic

This can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning...

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...
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...