there might be a hole/crack in the intake housing or tubing.. but the leak would probably be clearly visible to make a loud enought noise for you to clearly hear it. if its a stock intake, then its probably loose somewhere or leaking.
Wow well my K&N FIPK II whooshes, squeaks, whistles, and hisses depending on throttle position. It wasn't as prominent with the stock intake, but I had a crack on the big dome housing that had the filter in it. I've checked and double checked for leaks on mine and it's just coming from the filter sucking air in. Kinda cool to trick people into thinking it could be a turbo or supercharger. On my old grand am it did the same thing when I upgraded the intake. Don't know why you only notice it now?
How cold was it? On cold starts, it really has a continuous sucking of air sound until it warms up. Do you have an auto? My friend auto has the same K&N and it doesn't seem to be as loud as mine, but then again his is an 01.
its a manual. but i just started like a week ago, and ive had the car since december. even when its warmed up it makes the noise, im going to replace the throttle body and plenum anyways, whether it fixes it or not, im just curious if its hurting anything
Alright not to say one hear is wrong because im very new at this. I bought my 03 gt with an accufab, throtle body, and intake. Mine does that to that fricking hissing noise. I sprayed some stuff around the plenum and all the hoses to see if i could see any bubbles.....nothing, but the more I listen to it, I can tell its not coming from the intake. Its right like behind the accufab. Maybe it could be some gasket that is under the accufab? Like in between the accufab and the intake manifold? Help me out I got the same thing. Im going crazy.
If your still using the stock throttle body there is an air bleed screw on the underside of it that has possibly worked it's way out. I had the same thing happen on my 96gt. you may need to go to a junk yard to get a new screw if you cant locate yours. I can post a pic if needed.
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