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Why does my car start to overheat when I turn the heater on?

Why does my car start to overheat when I turn the heater on?

Your engine’s cooling system builds up an enormous amount of pressure. The net result is a searing hot jet of air flowing from the heater vents, and engine overheating as a result of little to no coolant flowing through the radiator.

Can a bad thermostat cause a car to run hot?

Faulty Thermostat The thermostat controls the flow of the coolant. Once the engine reaches operating temperature, the valve will open and coolant will begin to flow through the engine. A faulty thermostat might remain closed even when the engine is hot, which can quickly lead to overheating.

How do you tell if a thermostat is bad in a car?

Here are the signs your car thermostat is failing:

  1. The temperature gauge reads high and the engine overheats.
  2. The temperature changes erratically.
  3. The vehicle’s coolant leaks around the thermostat or under the vehicle.

What causes an engine to overheat?

Why Do Engines Overheat? Engines can overheat for many reasons. In general, it’s because something’s wrong within the cooling system and heat isn’t able to escape the engine compartment. The source of the issue could include a cooling system leak, faulty radiator fan, broken water pump, or clogged coolant hose.

What to do if your car heater is not working?

Solution: Set the heater to its maximum setting, remove the coolant tank cap and fill it to the proper level. Start the engine with cap still open and let the engine idle for a few minutes. If the coolant level should drop as the thermostat opens, top it up as necessary.

Why is my hot water heater blowing cold air?

Heater core exterior: The heat-radiating fins on the outside of your heater core could also be clogged with debris that makes its way in from the outside air intake at the base of the windshield. This can affect the heater’s output.

What causes an air lock in a hot water heater?

Air lock: An air lock is a large air bubble that forms in your cooling system as the result of a coolant leak or a recent coolant top-up. An air lock prevents the coolant from circulating properly and can cut your heat output. Solution: Set the heater to its maximum setting, remove the coolant tank cap and fill it to the proper level.

What to do when your car heater is blowing cold air?

Start the engine with cap still open and let the engine idle for a few minutes. If the coolant level should drop as the thermostat opens, top it up as necessary. This should bleed off the air bubble. When the engine is fully warmed up, put the cap back on and take a drive to see if the heat output has returned.