Run hot turn on heat run cool why is this?

1. Why does turning on the heater cool the engine?
2. How do I know if my radiator is blocked not circulating coolant?
3. How do I check if my thermostat is working?
4. Why is my car running hot but not overheating?
5. Does turning on the AC cool the engine?
6. How expensive is it to replace a heater core?
7. Can a heater core unclog itself?

Why does turning on the heater cool the engine?

Turn On The Heater

It draws warmth away from the engine and into the passenger compartment, lessening the burden on the engine's cooling system. In certain circumstances, that may be enough to reverse the overheating, he says.

How do I know if my radiator is blocked not circulating coolant?

Turn on your flashlight, and point it downwards into the radiator. Look for an uneven flow of coolant. If the radiator is blocked, the coolant will not flow evenly. Another quick way to check for a clogged radiator is to ask someone to rev the engine while you are squeezing the radiator hose.

How do I check if my thermostat is working?

Check the screen: Check the screen of the thermostat and make sure that it is lighted. A blank or unlighted screen could indicate a thermostat failure. Check the batteries: Many modern thermostats rely on battery power to operate. If the screen is blank or unlighted, a battery change could solve the problem.

Why is my car running hot but not overheating?

If you find that you've got a car running hot but not overheating there might be a few reasons: Clogged or damaged radiator. Low coolant level. Damaged water pump or thermostat.

Does turning on the AC cool the engine?

Air conditioning actually creates more engine heat in the engine compartment as there is more strain on the engine to operate the AC compressor. ... Either the fan operates at a higher speed to combat the extra engine heat generated, or there may be a secondary air conditioning fan that runs to provide extra cooling.

How expensive is it to replace a heater core?

Replacing the heater core can be an expensive job, and usually costs between $564 – $927 for parts and labor. The parts aren't particularly expensive, normally costing $80 – $234, but the location of the heater core means that labor costs tend to be quite high.

Can a heater core unclog itself?

Heater cores don't normally clog up on their own. It's usually caused by an outside force. ... If you run straight water in your cooling system or your cooling system is full of scale and rust, your heater core can clog up. While the engine is cool, remove the radiator cap and inspect the coolant.