Q: My car heater will blow hot air and drive fine for 30 minutes then my heater blows cold air and my car overheats

asked by on

My car heater will blow hot air and drive fine for 30 minutes then all of a sudden will blow cold air and start overheating I've change thermostat radiator water pump my radiator cap
My car has an automatic transmission.

Hello. With the recent repairs that have been made to the vehicle, there is only one main heating component that you have not looked into. This would be your heater core. The heater core is responsible for pulling hot coolant from the engine. This hot coolant runs through the heater core as the ambient air is pushed through to warm before entering the cabin. If the coolant can’t flow through the heater core, then the air will blow cold. This can be caused by a clog, a faulty switch, or a process known as electrolysis (electrical current running through coolant). Unless there is a clog that can be dislodged, these issues will all result in a new heater core. To get a precise diagnosis of the problem, I recommend having an expert inspect the overheating problem so this can be resolved.

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
  1. Home
  2. Questions
  3. My car heater will blow hot air and drive fine for 30 minutes then my heater blows cold air and my car overheats

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: radiator fan issue

I would suspect the cooling fan switch is bad or the two relays for the cooling system are bad. The cooling fan switch should be the most common problem, but for the price of the two relays in the engine...

Q: I'm not sure if it's a thermostat or the water pump that needs replaced

The heater not working in some cases may be related to the overheating problem you are also having. This may be due to a faulty heater blower motor or potentially a bad heater core. As you may know, the heater...

Q: Car won't start keeps starting then cutting out its a new battery as well

Hello. This is most likely not a battery problem if the car cranks over and starts even if it dies shortly after. This is more likely an air/fuel supply issue. There is something called an idle air control module in...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.