SikSide00GT

I have a 2000 GT (Manual) with 99,000 miles on it and i started noticing that my car makes a hissing noise when i turn it off, almost like air escaping out of a vaccum. Any ideas??? I have a K&N FIPK Cold Air Intake and some other mods.

impaled

mine does that with the K&N FIPK. i have had it on for a long time and it runs fine and doesnt seem to cause any problems.

SikSide00GT

oh ok. i was just wondering if it was just excess air running back out of the filter. My car runs fine its just weird to hear

GhostRider02GT

its the manifold releiveing itself of the vacuum. When the engine is running, the engine is sucking in air, then you turn it off and it is under pressure, so the air "leaks" into the manifold. After I turn my car off, I stomp the accelerator real quick and it makes this loud "SWOOOOOSH" sound. Try it out, its become a habit, everytime I turn it off, I do it, so do my other mustang buds

97targa

Well this shows how well your PCV valve is working...lol It's normal for a car to do when it's fully warmed up driving it a whileor maybe on a real hot day. If it does this excesively then you may have a bad egr vacuum sensor. It's that black thing just beside the egr that has a round black top that you can turn.

SikSide00GT

Wait, so the swoosh noise is a bad thing?

WhiteFoxGT

No, not at all. But our PCV system is supposed to surpress that. Dont worry about it

Blowby01GT

Its just the vacums releasing, mine has done it since the day i bought mine! Nothing to worry about

BlackMage

mine does the same thing

doug0122

+1