Q: Truck is overheating and heater won't work

asked by on December 18, 2016

I changed my heater core and hoses, changed my thermostat and flushed my radiator but it's still running hot and my heater won't work

My truck has 204100 miles.
My truck has an automatic transmission.

Hello. The symptoms you describe are commonly associated with air bubbles in the cooling system. If the cooling system was recently serviced then it may be possible that it needs to be properly bled of air bubbles. Air trapped in the cooling system can cause hot spots, which can lead to engine overheating as well as heater malfunctions, if they prevent coolant from getting to the heater. Another thing to look at would be the vehicle’s heater control valve, the component that controls coolant flow to the heater. If the valve gets stuck, or otherwise malfunctions, it may prevent coolant from reaching the heater core, which will lead to no heat. Another possibility is a worn or faulty water pump. A water pump with a worn impeller may no longer be able to properly circulate coolant throughout the engine, which can cause both of your symptoms. As cooling system issues like these can sometimes be difficult to diagnose, I would recommend having a professional technician, such as one from yourMechanic, come to your location to diagnose what may be causing your issues.

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

What makes a car's temperature normal at idle but hot while driving? - 2000 Chevrolet Malibu

This may be related to a few different things, such as a clogged radiator not allowing coolant to circulate properly, a thermostat that may be stuck closed not allowing coolant to flow through the motor, or potentially a bad coolant...

Car shuts off when trying to start.

Your key is a transponder key. The transponder in the key works together with the theft deterrent module that is attached to the ignition lock cylinder. The only good way to test this system is with a shop level scanner...

the high speed of coolant fan doesn't turn on when the engine overheats

Hi there. The high speed cooling fan is usually controlled by a spectate thermal switch, so it's possible that this thermal switch has failed. However, you should try as hard you can to obtain the correct ECU for this car,...

Related articles

Symptoms of a Bad or Failing Fan Clutch
If your car has a fan clutch, common signs include the vehicle overheating, the cooling fans working very loudly, or engine performance decreasing.
A Buyer’s Guide to the 2012 Chevrolet Camaro
The The 2012 Chevrolet Camaro is an exciting car that says a lot about American drivers and what we want. While fuel prices are high and the economy is just barely starting to resurge and stabilize after years of recession,...
What Typically Causes the Heating or AC to Stop Working?
While both the heating and AC are connected - to an extent - within your car, they’re actually...