Question

Can a bad idle air control valve cause overheating?

Answer 1

Yes a bad idle air control valve that doesn't slow down the engine RPM could cause the engine to overheat.

When an idle air control valve is working properly it should allow your engine to idle at a higher speed until the engine is warmed up and then after the engine warms up the engine should then slow down to a normal idle speed.

When the idle speed doesn't slow down and the engine is constantly running at a higher idle speed and the engine is now getting airflow by going down the road then the engine can indeed overheat.

If your engine idle speed doesn't go down then I would get the idle air control valve checked out and replaced if needed.

If you're noticing an irregular idle speed then your idle air control valve is likely bad.

Other things that could lead to an engine overheating are a bad cooling fan, low engine coolant, bad engine thermostat, bad water pump etc.

Answer 2

A bad idle air control valve does not always cause an engine to overheat unless the engine revs too high and does not slow down.

However the most common culprits of an engine overheating are thermostat failure, oil too low, low engine coolant, clogged radiator, broken water pump, cooling system, leaks, bad head gasket or bad radiator hoses, heater hoses, plugged radiator hoses.

When the idle air control valve fails, the bad idle air control valve will inhibit the flow of air through the engine.

When the car can't receive air, it leads to engine stalling.

The severity of this symptom can range from occasional stalling at first, to stalling immediately after ignition.