Help: my truck hiss'

[Dirtymaxx03]

sounds like some kind of air leak but it stops at 4psi. it will hiss from 0-about 4psi then goes away. sounds like its coming from the drivers side somewhere and its driving me nuts. i thought it might be a leak from my gauge but my gauge still works properly. its about to make me go insane. any ideas on whats driving me nuts?

 

[02ilduramax]

vaccum leak?

 

[Dirtymaxx03]

anyone else have a clue?

 

[R_F_F]

I'm assuming you've checked all of your connections after the turbo? Does it do it every time? Have a buddy hold the brake and throttle till it makes the sound while you look under the hood and see if you can find a more specific area.

Good luck!

 

[Dirtymaxx03]

it does it all the time and stops making any noise at about 4 psi of boost. had a guy tell me its normal. that its just the sounds of the air flowing throught the tubes. and the reason it goes away is because thats when air quits flowing it starts getting compressed causing the "flowing" sound to go away....idk but it makes sense.

 

[howie]

i had a hiss in mine that done it till 1500 rpms and than u couldnt here it anymore but turned out it was up pipe gasket

 

[Dirtymaxx03]

i really hope mine isnt an up pipe gasket. now im scared to look hhahaa

 

[howie]

If its a gasket it wnt cost u but bout 30 bucks and takes 20 r 30 mins