Hissing sound?

[Jordan]

My T/A makes a slight hissing sound right after i shut the motor off? its not very loud and doesnt last to long, but i was just wandering if anyone knew what it might be?

also when i first start her up, the idle runs high about 1500 for about 3-5 mins. is this normal?

[TraceZ]

That is normal, and more noticable with ramair because the intake is less baffled. That is the sound of the air in the intake after combustion is stopped by shutting off the ignition.

[Mirroredshades]

Sounds like a vacuum leak somewhere to me. Check for cracked rubber lines. Have someone turn the car off while you have you nose under the hood. Try to locate the hiss.

[mbigd73]

hiss

my caprice does the same thing .do you have a cold air intake . mine comes from the cone filter when i kill the car .

[TraceZ]

Re: hiss

Originally posted by mbigd73
my caprice does the same thing .do you have a cold air intake . mine comes from the cone filter when i kill the car .

Yup, and both the cars I've had with LT1s have done it. My 95 did it brand new the day I got it. I always thought it sounded kinda cool, actually. The 88 Iroc 5.7 i used to have did it too.