Air Intake noise when shutting off the engine

I have a 2015 4.0l Tacoma. When I shut off the engine, I hear this winding-down noise that seems to come from the passenger side, which I have been told it is related to the Air-Intake. I have talked to many Tacoma owners and no one seems to have this problem.

It does not happen if you turn on the engine and turn it off immediately when the engine is cold. Thoughts anyone?

 

Smog fan

 

Read the manual one day.

It explains it there.

 

Smog pump.
Its normal

 

I freaked out at first too. According to most experts/owners here, that noise is normal. I started liking it. It sounds like super charger

 

Super charger... at least thats what I tell all my friends

 

Blower doesn't wind down tho.

From now on tell em turbo.

The Roots blower rattles on shutdown

 

Thanks ill go with , "its a inline turbo, thats why you can't see the actual turbo"

I have literally had guys look under my hood and some say they can see the supercharger...
My truck is 100% stock performance wise lol

 

Rear mount

 

Lies.

 

It's the smog pump saying hello

 

Mine does the same. It's normal.

 

Totally normal. I love the "inline" turbo..

 

I think of the sound as turning off a model T. Puh..Puh...Puh...peshhhhhhhhhh