After shutoff, noise coming from engine compartment?

[peterjbrown71]

After the second oil/service was performed I started noticing a noise after shutting the truck off. It sounds exactly the same each time, like some sort of electric motor running a short sequence. Last for about 2 seconds. Just seems odd. Anyone have this issue or any thoughts?

[peterjbrown71]

Should have mentioned... 2014 5.3L Silverado

[brokesilverado]

Mine does the same thing. Also the 07 impala I traded in on my truck made the same sound.

[peterjbrown71]

I'm going to test the AC theory I've seen here about purging. I'm going to run a few days with it off all the time and see what happens.

[Arnoldthepig]

My truck made a noise similiar to blowing across the top of a beer bottle. The noise came from the engine compartment but I could not pinpoint exactly where. I brought it to the dealers attention during a recall visit and they said the afterblow feature was turned on.

[TKhawk01]

I've noticed that if I'm driving in auto 4x4 sometimes when I shut the truck off there is a noise like the one you described that comes from the transfer case. It is probably the transfer case shifting back to 2wd.

[BluByU14]

My new 2015 Sierra does it....usually lasts for about 5 seconds. Didnt notice it on my 2014 Sierra

[peterjbrown71]

TKhawk01- Now that you mention the 4x4 transfer case, that is what it sounds like. Will test this out by running in 2wd only. I notice on the 2015 3500's they selector switch only has 2wd, 4hi, 4lo, no AUTO feature.

[peterjbrown71]

Well, after testing this certainly appears related to the 4x4 transfer case switching in and out. Since new, I've operated in the "auto" mode. There haven't been any road conditions that would have called for the automated system to switch to 4WD (it has been manually placed in 4WD a few times when needed).

 

The sound didn't start happening until 13 months and about 18,000 miles. After running last week in 2WD only, no noise. Doesn't seem overly concerning, but it seems odd the noise wasn't there all along. Seems like I might be getting better gas mileage in 2WD mode only. Wondering if the transfer case had been switching in and out of 4WD inappropriately?

[MikeNH]

After the second oil/service was performed I started noticing a noise after shutting the truck off. It sounds exactly the same each time, like some sort of electric motor running a short sequence. Last for about 2 seconds. Just seems odd. Anyone have this issue or any thoughts?

 

 

My 2011 and just about every other GM I've driven as a rental (and Enterprise/National says I rented 46 times in 2014 for reference) makes a rapid click-click solenoid noise a few moments after shutdown. No idea what it is but since literally dozens of different models have done the same thing I'm not worried.