I have a small problem I think, When I cut my car off coming from the engine it sounds like air is releasing from somewhere, it last for about 5-10 sec and then quits... I thought maybe a cracked intake or a leak with the egr... ( I dont notice any cracks in the intake) Anybody recognize this?

 

Usually that means your car is running a little hot or you have a buble in one of your water passageways that might by slowing down the rate of the water flow through the engine.

Another possible reason for this sound, but normally only happens in carburated cars , is that the fuel is getting to hot, causing fuel vapor to seep out, which can also cause vapor lock. Te vapor doesnt take that long to escape though, only 1 to 3 seconds.

It sounds like the most likely problem is the first possibility I mentioned.

 

It also could be coming from the AC. That hiss happens on my brothers car but only after he closes the door.

 

+1 on the AC system.
The vent location is actually controlled by the vacuum from your engine.
(listen for the hiss the next time you change from floor to windshield)

 

it's most likely the A/C, i hear mine all the time so i wouldn't worry

 

I don't know what causes it, but I can say that I have ridden in two other mustangs, a 2000 gt and a 2001 mach 1, and they both did that. Mine does it too and it's a 97 gt. All three of them do that when they are turned off and those cars don't have anything wrong with them. Just thought I'd throw that out there.

 

Its the A/C.

 

A/c mine does it to