Whirring Sound After Engine is Turned Off

[Glen1023]

Hello all,

This sound is not the sound of the EPB engaging after turning off the car with the Auto Hold feature engaged; I’m very familiar with that sound.
The sound I am hearing which I only can hear in my garage is coming from under the hood; I heard it last Saturday and earlier this evening.
The whirring sound starts high and after about ten seconds whines down, sounds kind of like the engines of a plane powering down after pulling into the gate.
I won’t compare my previous 14 SX-T and 16 SX-L to my GT1, but is the sound I’m hearing the turbos spooling down? Maybe the radiator fan kicking on?

 

[2Slo4u]

My guess is your hearing the Turbos spoiling down

 

[Glen1023]

My guess is your hearing the Turbos spoiling down

Thought so, and my wife reminded me her 2020 Santa Fe Limited 2.0T has that sound to on occasion after shutting off her car in the garage.

 

[SteveCo]

Cooling fan continuing to run after engine shut off. If it was turbos, they'd spool down immediately as the input exhaust stops - not after 10 seconds.

 

[eflyguy]

Turbos do not "keep spinning". They are air pumps. Without exhaust, there is no driving force and nowhere for the air they move to go.

 

[nhcowboy28]

Automotive flatulence

 

[2Slo4u]

Cooling fan continuing to run after engine shut off. If it was turbos, they'd spool down immediately as the input exhaust stops - not after 10 seconds.

Wouldn’t the cooling fans stop when the engine stops as well? Assuming they are belt driven...

 

[falanger]

Were your headlights on right before turning off the car? Sounds like you're describing the cooling fan in the headlights. If you listen closely, you'll hear a high pitched whine until the lights go off, then the fan stops a few seconds later.

 

[Glen1023]

Were your headlights on right before turning off the car? Sounds like you're describing the cooling fan in the headlights. If you listen closely, you'll hear a high pitched whine until the lights go off, then the fan stops a few seconds later.

As a matter of fact they were.
Did not know the headlights had a cooling fan.

 

[Sime]

Assuming they are belt driven...

Not many of those around these days.

 

[NS_Stinger]

Wouldn’t the cooling fans stop when the engine stops as well? Assuming they are belt driven...

Cooling fans can continue to run long after the car even shuts off. If you drive on a very hot day and park and turn off the car you might still hear them running for sometime after the car is off trying to evacuate the hot air from under the hood. Its totally normal and designed to keep engine and under hood temps under control.

 

[Silvermanor]

I definitely have this. Right as I turn the car off, there is a loud whirring from the front. Thought it was the turbos as this is my first turbo car but maybe its a fan. Winds down over about 10 seconds and sounds like a turbine slowing down.

 

[Glen1023]

I definitely have this. Right as I turn the car off, there is a loud whirring from the front. Thought it was the turbos as this is my first turbo car but maybe its a fan. Winds down over about 10 seconds and sounds like a turbine slowing down.

Yes sir, but happens sporadically though.
Somebody said the LED Headlights have fans in them to cool them, but I think it is the radiator fan.

 

[Silvermanor]

Yes sir, but happens sporadically though.
Somebody said the LED Headlights have fans in them to cool them, but I think it is the radiator fan.

Yeah, definitely coming from behind the bumper. No way headlight fans are that loud.

 

[Glen1023]

Well my wife’s 2020 Santa Fe Limited does that on occasion to.

 

[MerlintheMad]

"Headlight fans", lol. LEDs are cool, not hot. It is the Net. It must be true.

 

[Glen1023]

"Headlight fans", lol. LEDs are cool, not hot. It is the Net. It must be true.

That is what I thought, the s#$t you read online is very humorous.
The radiator fan seemed a much more likely story as to the sound I was hearing after shutting off the car.

 

[General_Vodka]

I know I got aftermarket LEDs for my wagon and they have a fan in them. But they are tiny. So no way the sound you hear is the lights. Probably the fan.

 

[MerlintheMad]

I know I got aftermarket LEDs for my wagon and they have a fan in them. But they are tiny. So no way the sound you hear is the lights. Probably the fan.

Is this standard practice, to put tiny fans inside LED (or other) headlight assemblies? Because until it was mentioned here I've never heard of such a thing and thought our virtual legs were being pulled. (But, until this week's ongoing bathroom renovation, I also had never heard of, or seen - to my knowledge - a GFCI power outlet; apparently these are bog standard requirements for any outlets near a water source, i.e. sinks, tub, etc; and have been code for quite a few years. So, take that missing bit of knowledge from my "database" as you will: fans inside headlight assemblies could clearly fall into that category.)

 

[General_Vodka]

Is this standard practice, to put tiny fans inside LED (or other) headlight assemblies? Because until it was mentioned here I've never heard of such a thing and thought our virtual legs were being pulled. (But, until this week's ongoing bathroom renovation, I also had never heard of, or seen - to my knowledge - a GFCI power outlet; apparently these are bog standard requirements for any outlets near a water source, i.e. sinks, tub, etc; and have been code for quite a few years. So, take that missing bit of knowledge from my "database" as you will: fans inside headlight assemblies could clearly fall into that category.)

Well you see, a ground fault circuit interrupter is pretty useful in a place like a bathroom where there is potential for shock. We even have them in our kitchen counters. Otherwise you might get zapped when your drying your hair. You also don't want to be killed by a toaster. Lol
As far as the headlight fans go, high end aftermarket bulbs often have them to improve the lifespan. LEDs do run a lot cooler than halogens but that doesn't mean they enjoy heating up and cooling down every day. Also the driver powering the LEDs run a lot hotter than the LEDs, so they tend to fail long before the LEDs themselves do. That's why a lot of cars have failing DRL LEDs, because the driver is failing and is taking the LEDs out with it.