When Should Radiator Fan Come On?

[duffner]

03PTGT radiator fan seems to be coming on more often than not.... It seems to be coming on after 20 minutes of hwy driving (65-80 mph) but the AC has not been on. Is that normal? Only changes to engine was timing belt about 4 mos ago.... Any ideas? Thanks - Duff

[slartyblarfast]

Is it running while your on the highway or when your just sitting? I know this may seem simple but if the weather hotter than usual the fan when run more. Especially when idling. Coolant may be a little low also. Did you put a water pump in when you had the timing belt done?

[duffner]

It's on when I'm idling but not sure about on highway (not to sound stupid but how do I determine that?) I don't recall changing the WP but will check the fluids. Yes I notice it now more in the summer temps. Is it possible that the low speed is not working and only the high works?

[slartyblarfast]

That is entirely possible. The fan will also run when the a/c is on. Sounds like the fan is probably doing ok.

[duffner]

This morning as with all mornings for the past month, the radiator fan is on "High" when I stop at Dunkin Donuts ..... So the weather is between 55-65* in the AM, so it's not hot outside. I will check the following:
1) Does fan "LOW" come on when I start car
2) Are fluid levels OK

Anything else I should check?

Thanks - Duff

[soonercruiser]

Check out the Maple covered cake donuts; they are killers!!!

[Hooligan]

Frank, what happened to IHOP???
Hooligan

[CREWZIN]

Originally Posted by duffner

I will check the following:
1) Does fan "LOW" come on when I start car
2) Are fluid levels OK
Anything else I should check?
Thanks - Duff

No fan should come on when you first start the car UNLESS you have the HAVC control set on Air-Conditioning or De-mist. De-mist throws air towards the windshield and also turns on the compressor. Either of these will turn on the "low fan" (from what I've read). The "high speed" fan only comes on when a certain water temperature is reached.

[duffner]

I do notice my temp going up one notch (1/4) above half way (horizontal). It's never done that before. I'll check the fluid level tonight. Is there a way to tell if the thermostat is OK? Does the waterpump and thermostat get removed/reinstalled during a timeing belt replacement job? I'm hoping it's just fluid level....

[CREWZIN]

Originally Posted by duffner

I do notice my temp going up one notch (1/4) above half way (horizontal). It's never done that before. I'll check the fluid level tonight. Is there a way to tell if the thermostat is OK? Does the waterpump and thermostat get removed/reinstalled during a timeing belt replacement job? I'm hoping it's just fluid level....

Temperature gage should say right in the middle all the time.

Testing the thermostat, read here:

Car accessories, car security, spoilers, car seat covers, car alarms, car styling, body kits to buy online in UK and Ireland.

Water pump should be changed during a timing belt change but ONLY if it's asked for. Mechanic won't do it just because the timing belt is being worked on but any good mechanic will advise the owner to change it and the belt tensioner when he's changing the timing belt. The thermostat is not touched while the belt is being changed.