Why does your Ford Taurus - Mercury Sable heat work fine above idle but gets cold at idle?

Answer 1

Two possibilities

• Engine coolant levels are low
• Water pump - impeller can wear down or come loose from the shaft

Add coolant to the reservoir on the left side of the engine compartment (reference Owners Manual for more detail.)

Might be a good opportunity to think about getting the system flushed and coolant replaced...

See "Related Questions" below for more, including coverage of the water pump

o. You need to check the level of anti-freeze on your radiator. Mine was low and not allowing fluid to flow through the heater core.

-Thank you, yes, I had the radiator flushed, and it is working better now.

Check your coolant level is topped off in overflow container. had same problem ,temp gauge is ok because the coolant wasn't reaching the heater core, but the engine is being cooled at the thermostat portion of the engine

Low coolant?

Bad thermostat?

I believe there are series of devices called heater hoses/plugs that cool the engine and provide heat for the cabin upon demand. If these are broken or clogged, the heat won't work and the car may overheat when not moving. Get them replaced by a pro; it's a lot of work.

Well, of course it is going to be cold, until the engine warms up. A problem with it though, is that the coolant level may be low and that is why you would only have heat at higher rpms.