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 October 03, 2016

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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

Radiator not holding water

This is a common issue. Many of the radiators installed in vehicles are aluminum cores with plastic water tanks. There is a gasket that seals them together. Over time the gasket fails and water starts to leak from between the...

My back rear tire is leaning inward at the top and wheel is getting some tear on the inside of the tire

If you have one of the rear tires leaning in then you have damaged the upper control arm or spindle is bent. Have the vehicle suspension checked for damaged components and have alignment done.

Hole in radiator, leaking

Any leaks in a cooling system, including those in a radiator, can be repaired by requesting YourMechanic's mobile diagnostic and repair services. So, you need not move the vehicle. If you would like the radiator replacement performed by a certified...

Related articles

Lincoln Certified Pre-Owned (CPO) Car Program
Lincoln certified pre-owned cars are under 7 years old, have less than 60,000 miles, and come with a 6 year or 100,000 miles comprehensive warranty.
How Long Does a Radiator Last?
Your Your car’s coolant system is vital to ensure that the engine stays within operating temperature limits and does not overheat. It’s comprised of several different components. The radiator is the largest, but there are others, including the upper and...
A Buyer’s Guide to the 2012 Lexus LS 600h L
The The “h” stands for hybrid, and while you might hope to get greatly improved gas mileage for your effort to go green, that shouldn’t be your motivation for buying this model. The 600h L offers a mere 1 mpg...