Maybe you all can direct me? I've looked in the forums but I haven't found anything that sounds similar to what I'm trying to find out.

The other day, I parked and turned off my car and then about 1 1/2 seconds later this loud whirring noise begins - almost as if the car is turned on. It never happened before this so I thought it was something else outside in my neighborhood. I listen a little more closely and notice that it's the car. So I get back in and start her up and let her run for a couple seconds then turn her off again and it went away. It happened again the next day and I did the same thing - turned her back on, then off again.

What would be the cause of this? Do I need to be worried? Has this happened to anyone else?

 

It's the fan. It comes on to cool the car down. Once you turn off the car, the coolant stops circulating, so the fan comes on to help purge heat.

 

I would think it was the fan trying to cool down your engine? Always had a fan start up after shutting cars off (bmws anyway).

 

It's never done that before, that's the only reason I'm asking. My other cars never did that either. Could it be because lately it's been hot? The 2nd time it that, it was night out and relatively cold.

 

It really is the fan -- but I'd have the temp sensor checked, sometimes it malfunctions and makes the fan go longer than needed. The fan can go longer in the hot summer months or after some spirited driving, but I'd still have a little check to make sure the sensor isn't acting up.


Hugs,
PB

 

Yup. Cooling fan.


That's a GOOD thing. (It is a little disconcerting the first few times you hear it though).

You'll notice it comes on when you stop moving. (to keep air moving over the coils)

 

I'm not trying to be negative or condesending, just imformative.

Odd fact about car engines, is that they are both air and water cooled. Your radiator @ the front recieves hot water from the engine, and transfers the head to the metal fins. These fins allow air to pass between them, picking up heat, and cooling the metal fins, and thus the water passing by. The cooled water then travels back into the engine, cools the engine by taking the heat away, and repeats the above process.

To improve this process, most cars have a radiator fan, usually mounted behind the radiator, so that while cool air slams into the front of the car & radiator, some of the air going under the car us sucked in and blown against the backside by this fan.

That said, when you're not moving forward, you do not have the air from the front cooling the radiator. Sometimes the fan will not even turn on with enough forward momentum to keep the engine properly cooled, but it will turn on if the engine gets too hot. It is very common during warm/hot temperatures, for the fan to kick on, even if the car is turned off, and the keys removed.

I'm no mechanic, so I could be wrong on some of that... But I work with lots of electronic cooling systems, and the theory is the same. I could go more in-depth as to why, but that'd probably be overkill.

 

Whew! okay, this makes me feel a little less worried then that I'd have to spend mucho dinero on her.

Thanks guys and gals!