Heater Not Getting Hot Enough

heater core in your car
My Cadillac was not getting any heat so we replaced the heater core, it was plugged bad. heat worked good for about one week. Then heat went away and water was disappearing from the radiator.

Changed the water pump (it was leaking) new thermostat, radiator cap and new fluid. Still no heat, just cold air. Any other suggestions. Also the overflow tank is always full. My husband took some out because it was too full and then today it was full again.

Could it be a head gasket (someone suggested that) and would that make the heater not work? Car does not overheat and runs good. Also with the thermostat removed car has a little heat blowing out.
thanks,
Linda

 

Hi there Linda,

If the old core was plugged up with rust, I would imagine the radiator is also plugged up and not allowing the hot antifreeze to circulate through out the engine. No hot antifreeze going through the two heater hoses at the core…..results in NO hot air coming out of the vents inside the car.

If you have two very hot heater hoses, then you most likely have a control problem inside the car…..stuck cable in the dash, or control head problem in the dash etc.

Here is a video on how to FLUSH your heater core of rust

Here is a video on how to BYPASS the heater core, if it is leaking coolant its a temporary fix

Blessings,

Austin Davis

Posted in: A/C and Heater

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • Kirk Quesnel

    hi my wife is away far from home and has a problem with our 2003 monte carlo 3800 series 2 when the car is sitting running it will blow heat but once she gets out on the road at highway speed the air it is blowing is not very warm at all and we are in winter temperatures here in Manitoba Canada the temperature gauge is working and shows about half when idling or driving slow but shows cold when it is on the highway.

  • Kirk Quesnel

    hi my wife is away far from home and has a problem with our 2003 monte carlo 3800 series 2 when the car is sitting running it will blow heat but once she gets out on the road at highway speed the air it is blowing is not very warm at all and we are in winter temperatures here in Manitoba Canada the temperature gauge is working and shows about half when idling or driving slow but shows cold when it is on the highway.