s13:firewall knock?

[240_of_pa]

hello. i guess i have an interstinf problem. well not really. everytime i close my pass. or driver door, i hear "knock" somewhere just behind the firewall in my s13. its delayed by like 1/4 second after the door closes. has anyone heard of this before?

[corn322]

does it on my car too. I think (and so does my dad) it's the flap for the a/c system that lets inside air in or not.

edit: that should be "lets the outside air in". if it let the inside air in, everything would turn inside out and the world would explode

[240_of_pa]

nyuck nyuck nyuck. thanks. that sounds viable. as long as its not a monster hiding in there or something.

[Jadius]

It does it on my car too. I was wondering what it was and where it was coming from. I thought I was basically the only one with that problem. Guess not !!!!!

[240_of_pa]

yo guys. turn on the recirulation button for your a/c control. i did it yesterday and the sound went away. i think you were right corn. it must be some valve or flap for the outside air that is making that noise.

[ssnnooppyy]

inside out air coming out from the inside.... that's funny. Imploding nis, not so funny. Dewd, I am happy to now have a fix for one of my gremlins... must chase more.