Out Of Curiosity Problem With Cooling ?

[albi969]

Hello All

Can any one enlighten me if the front fan on the radiator of my 98 Corolla lift back is just for the heating or is it for cooling as well via the thermostat.?. As the car has a twin set up one rear and one front of radiator.

Reason I’m asking is because rear one is white and the one on front is black and seems to only start when I turn the heating controls on with air con on, and stops after a few seconds , is this normal ?

Must add that the car had only been running for a few minutes when I turned heating on , and only really tried out of curiosity, to see if both fans came on simultaneously.

Nothing to worry ‘bout or have I stumbled across a problem ?

Thanks in advance for any info.

Cheers Albi

[dvdmeister]

Well I would say that both are cooling fans - theres never a 'heating' fan around the engine radiator. The hot air you get in the cabin via the air vents is from a separate little radiator (called a heater matrix usually) which is in the same circuit as the engine cooling system. Thats why you only get warm air when the engine is warm.

The radiator at the front of your car is for cooling the engines coolant, and the fan is to assist this process if you are not moving fast enough to create a good airflow across the radiator. If you have air con, you will have a second radiator usually in front of the primary engine coolant radiator, and its usually smaller. Again, any fans in front or behind of it will be to cool the air con coolant down.

Not sure exactly why the white fan comes on only for a few seconds when the air con is on, but I suspect if you leave the air con on for a while with the car not moving, the fan will come back on and stay on. It could be a diagnostic thing, to check that the fan still works. I'm assuming by 'heating controls' you mean the interior blower fan - which would make sense, because the air con doesnt actually switch itself on until you have the blower on AFAIK. You should be able to get both fans running if you come back from a drive with the air con on, and leave the engine running for a few minutes when its parked. Probably one fan is controlled by the engine coolant temperature, and the other by the air con system.