Radiator Fan Runs After Engine Is Shut Down For A Minute?

Question

My radiator fan runs after engine Is shut down on hot days for a minutes. I don't see the point of this why does It do this on hot days, the only thing It's doing Is cooling the radiator and the fluid In the radiator I could see If the water pump Is circulating to. But just the fan Is running then shut Itself off.

Answer 1

That's supposed to work that way. The fan is controlled by a thermostat. Cooling the coolant in the radiator still removes heat from the system. True, the pump isn't running, but there is still conduction of heat through the fluid,

Answer 2

When you park the car, the engine is hot and the thermostat is open. The fans run and cool the coolant in the radiator. Even though the water pump isn't running, you still get some coolant flow as the colder coolants contracts and draws hot coolant out or the top of the engine. That prevents the hot coolant from rising and overheating the cylinder head.



As long as the thermostat remains open and the radiator fans run, you'll still get some slight coolant movement and that movement is enough to prevent damage.

Answer 3

I’ve seen a few cars do this over years. I think maybe some engineers design some to do this, because coolant temp does rise for awhile after engine shutdown. This causes pressure in system to rise also and force coolant into overflow tank. As system cools it draws coolant back out of overflow tank back into radiator. During this process some coolant is lost thru evaporation from overflow tank. By running fan for short period after hot shutdown, transfer and evaporation is minimized from overflow tank.

Answer 4

On some vehicles, this is by design to cool the engine down after running. This is called the hot soak period. If your car has just started doing this, then you may have a relay sticking causing the fans to not shut off.

Answer 5

I've seen cars do this for numerous years. It's normal and won't be a problem, unless your battery is on its way out. Then that extra minute or two of fan(s) running could prevent your car from starting. The manufacturer obviously thought it was important to shed the heat, so just tolerate it. Hearing your fan lets you know it's still working. Then you can worry if you DON'T hear the fan.

Answer 6

That is common on front drive Chrysler products and Honda products.It is not normal and it can usually be traced back to the shutdown relay or the fan relay.Some will run till the voltage drops enough for the relays to stop working.

Answer 7

So what's the year, make and model of your car? If the water pump is spinning as well as the radiator cooling fan the block and cylinder heads are being cooled.

Answer 8

It helps reduce the temp. which in turn helps reduce the static pressure in the radiator after the immediate shut down. I would think it is to try and help prevent damage to the radiator such as a blown seam or hose.

Answer 9

They don't run off of your crankshaft - they'll run until temp. is within normal range.

Answer 10

Normal. Computer say's it still needs cooling.

Answer 11

The fan runs "as needed," to cool off the coolant. Vs. in the old days, it would be on the end of the crankshaft.

Answer 12

the fan turns on when the fluid in the radiator is above a specific point.... and turns off when it is below that point

Answer 13

a normal condition to prevent boiling over.

Answer 14

very normal. when the coolant is at a temp, the fans should be on.

Answer 15

Bad relay