Loud air pump sound???

So when I turn on my truck and turn off my truck a lot of the time theres theres a really loud air pump sound that happens anyone got a cule what it is? its defiantly coming from under the hood out side the cab. The only thing that I have installed is an AFE drop in.

 

My old Honda Accord used to do that with a K&N cone filter. Not sure its the same sound though?

 

What year is your truck a 12 or 13? the 13's supposedly have a more pronounced noise from the air pump. I honestly think people got a little too much sand in their va jay jay because I notice every little sound and feel every little hiccup but even on the 13's we got at my dealer they don't sound bad at all. It sounds like a normal Tacoma (like a diesel with that loud fan, lol).

 

Ive noticed my '11 making that sound when I first start it in morning, goes away when it warms up. Sounds like compressed air going through something, never heard it until few weeks ago, maybe just never noticed it.

 

^^Yah its just for a short time maybe 30 sec or less and then it shuts off. I dont remember it it was making that sound before the AFE but my dad has the same exact truck and his doesn't make that sound at all.

 

No one else has really posted on your thread because I answered your question for you and the AFE filter you put in is irrelevant to the situation you are describing. By the way I wasn't trying to be rude or anything just being direct to the point, lol.

Again.. what year is your truck, 12 or 13?

 

ac system pressure equalizing

 

it might be the new fan (dont know exact name) for better emissions. it is located on the passenger side of the engine bay

 

This ^^^. Emissions control system pumps air into the exhaust.

 

2011s don't have the air pump. If you have a TRD Off Road, there's an electric brake pump that runs periodically to charge the reservoir. Other trim levels don't have it and use a conventional vacuum booster.

 

its a 2012 says it in my one liner

 

I have a 2013, its the air pump, completely normal. I kinda like it.

I really only hear it when I turn the truck off.

 

Sounds like a vacuum cleaner beaing turned on and off.

 

Yup its the Air Injection Pump.........pumps air into the exhaust to help emissions when starting vehicle.

 

So... they reduce pollutant ppm counts by diluting it with clean air?

 

Liar, you just changed it because it didn't say that when you first posted.

I hear it every once in a while too, while I hate the idea of a pump paying homage to way back to the god given 70's I gotta say i do like the sound of it when I do hear it every blue moon also

Oh come on, it's not that bad.

Exactly.

It actually reduces emissions by over 50%... why it is back in a modern day engine that should be running very clean in the first place I have no idea.

What they should be trying to figure out is how to recover that 70-75% efficiency loss that a modern day engine still has, so it can run at 100% at all times.

 

Yes, reduce emissions by 50% by pumping twice as much air through the tailpipe. Another stupid EPA mandate.

 

The point is to reduce the emissions more before they hit the cat converter, or at least aid with the reduction process of the catalyst. Who cares as long it's clean by the time it exits. That's why they do not like exhaust leaks.

I know it's stupid, but it is what it is.

 

Not true, 2011 4 cylinders do in fact have air pumps. But you are correct in the sense of the 2011 6 cylinders not having it.

 

Hell no... lol.