Engine temp higher with heater valve closed?

[kmoses]

Does the engine temp get higher when the heater valve is closed?

[ORFORD2004]

It's possible because the heater core is another radiator.

[124JOE]

the differance is nomanal


if you are getting higher than normal temps
you may have an air bubble trapped under the thermostat

[kmoses]

I know some cars have a bypass valve that when closed, isolates the heater core but keeps the coolant flow path open. It was just one of those "what if" considerations. Thanks!

[narfire]

When sitting in Tim Horton's drive through, sometimes the temp climbs and the fan will kick in as it is supposed to do, then I might open the heater and the coolant going through the heater core drops the temp pretty quickly.

[kmoses]

I will keep that in mind. Did you also turn on the heater fan or just open the valve?

[lglade]

Modern cars are so efficient at heat management that you don't hear this advice any longer, but back in the 70's when I was learning to drive we were taught that if your car was overheating to first turn off the A/C and to then turn on the heater. The A/C creates extra load on the engine (so get rid of the load) and circulating coolant though the heater core allowed you to remove additional heat before circulating the coolant back through the engine.

[ideashappen]

Modern cars are so efficient at heat management that you don't hear this advice any longer, but back in the 70's when I was learning to drive we were taught that if your car was overheating to first turn off the A/C and to then turn on the heater. The A/C creates extra load on the engine (so get rid of the load) and circulating coolant though the heater core allowed you to remove additional heat before circulating the coolant back through the engine.

This information is right coupled with the variable that the heater fan itself is causing air to forced over the heater core's cooling fins is why you can seriously decrease engine temperatures on older model cars. I have had to do it a million times...... ok.... slight exaggeration but over my many years and many various vehicles it became standard practice before I actually just pulled the thermostat out during summer months.