[numbaonechief]

Ive had a hiss for a long time but now im sick of it. Its constant at idle until i give it gas. It goes away when im driving and giving it gas, but comes back when i let off the gas. I'm figuring its the IAC but the whole carb cleaner tricker isnt working on any part of the engine. Any other ideas ?
On a side question, whats the sound difference of a vacuum leak versus an exhaust leak ?

 

[bottled2v]

a vacuum leak sounds like it's sucking air or sort of like a hiss like you described. an exhaust leak sounds like a ticking and can be mistaken as a sort of "knock" by someone who hasn't heard both an exhaust leak and an engine knock. as for the issue, when it's idleing unpulg the iac, if it's working correctly the engine should almost stall/idle way down when unplugged, some cars will also stall it all depends.

 

[numbaonechief]

Well I went to a mechanic and he said th electricals on the iac are off so replace it. Nowwhat im not so sure about is that he said the reason I have a hard jerk when deccelerating is the iac not going down to idle fast enough (even though im in gear?) Any merit to this? Also said my messed up quad shock is the reason for the ENTIRE drive train moving during turns making all that noise I thought was a bad trans.mount.