New K&N air filter making sucking noises.

**Banse** · 09-26-2013

Hey everyone I just installed a new k&n conical air filter into my 2002 GP GTP. Since the install every time I turn my engine on the air filter starts sucking in air and sounds vacuum like. Now it does stop the noise after about 30 seconds to a minute. If I start driving before it stops I can hear it when I am on the gas (going around 15-20 mph because I live in a neighborhood with lots of children. It goes away though in 30 seconds to a minute driving idling. Doesn't make a difference. Basically my air filter didn't do that when it was stock.

Now i do not know if this makes a difference but I had to leave half the stock air filter in so it could hold the computer system that sits in the stock air filter. I couldn't find any other way to keep it safe. So I was thinking maybe it sucking is being echoed by the old half of the old filter... I'm probably way off but I really don't know what to think.

So please and thank you for taking the time and possibly posting a solution off suggestion.

**Fivefingerdeathpunch** · 09-26-2013

The sound you hear is really just the air passing through the IAC's passage inside the throttle body.

Aftermarket intake systems allow that noise to be heard because the stock air box and tubing baffles arent there anymore.

**Banse** · 09-26-2013

Do all K&N's do that? I have a buddy who has one on his Trailblazer SS and I've never heard it on his.

Regardless though nothing I should be worried about in the least? And is there a way to stop it besides switching back to my old one? Also how come it only does it when I first start it?

I just get very anal about noises and stuff of that nature it being my first nice car and all.

**Booba5185** · 09-26-2013

The IAC is open while the engine is warming up, once it closes, you don't hear it anymore. If you did still hear it after the engine was warm and running for a minute, you'd have a vacuum leak. The IAC is basically a computer controlled vacuum leak that still leaks in filtered air. You could build an air box around your filter to help hide the sound, but that can get pretty pricey. Other than that, there is not much you can do.