Whirring after engine shut-off

[Opus]

I'm not sure if this is normal and I just haven't noticed it as much before. Shutting off the Jeep I continue to hear a whirring sound like a fan running. I know it's not the main radiator fan. The sound seems to be coming from somewhere just behind the passenger headlight. I have the Jeep set to keep the lights on for 30 seconds after engine shut-off and when the lights go out, so does the sound. Today, after I heard it and the lights/fan went off, I tried opening the door to make the lights come back on and the whirring sound resumed as well. Does the turbo cool down on it's own after the engine is shut off?

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[JustinJ]

I'm not sure if this is normal and I just haven't noticed it as much before. Shutting off the Jeep I continue to hear a whirring sound like a fan running. I know it's not the main radiator fan. The sound seems to be coming from somewhere just behind the passenger headlight. I have the Jeep set to keep the lights on for 30 seconds after engine shut-off and when the lights go out, so does the sound. Today, after I heard it and the lights/fan went off, I tried opening the door to make the lights come back on and the whirring sound resumed as well. Does the turbo cool down on it's own after the engine is shut off?

So normal. Engine cooling down

 

[Opus]

So normal. Engine cooling down

Does it do the same thing in reverse? Warming up as well as cooling down? I just went out to the Jeep and opened the door (it's cold now) and the headlights kicked on as did the sound.

 

[Opus]

Hmm... I think I might have a culprit. When I checked it again I placed my hand on the headlight and I could feel a slight vibration. Then it hit me that the Beamtech H13 LED bulbs I installed have a cooling fan in them. With daylight savings it's been darker by the time I come home so the headlights have been working more. The fan may have been cooling down the bulb.

If that's the cause it's a little odd that it's only on one side. And I'm not sure why it would have kicked on after the Jeep was cold. I'll have to keep an eye on it.

 

[watchluvr4ever1116]

Does it do the same thing in reverse? Warming up as well as cooling down? I just went out to the Jeep and opened the door (it's cold now) and the headlights kicked on as did the sound.

I’ve had other vehicles where the fuel pump primes when the door is opened, mainly my last 4 MINI’s. I’ve not paid close enough attention to tell you whether my Jeep does it though.

 

[Heimkehr]

the Beamtech H13 LED bulbs I installed have a cooling fan in them.

[The sound occurs] only on one side. And I'm not sure why it would have kicked on after the Jeep was cold.

As someone who's used fan-cooled LED headlights, the fans should operate only when the headlights are energized. If one headlight bulb is observed to be making sound and the other not, irrespective of whether you want the headlights to have power at a particular point in time, you'll want to consider removing the bulb on the silent side to check for proper functioning when 12V is applied.

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