Loud hissing noise coming from where the air filter sits in my 86 s10 chevrolet...

[Shane]

...blazer...? Whenevrr i have the truck running i always hear this reallly loud hissing noise coming from inside where the air filter sits. Theres a couple wires in there but i thought maybe it was coming from the vaccuum hoses. But i cant find those to see if thats the priblem. Anybody have any ideas or guides i can go through to see what the problem is.

[Humveetech]

what above said, you sure it isnt the engine drawing in air????

[Me]

HI, THERE'S A LOOSE VACUUM HOSE OR IT'S CRACKED , HAS A HOLE, ETC. O.K. ?

[Mikey]

It is normal to hear some hissing from the inside of an air cleaner because of the obvious way that fuel is introduced into the engine, however you are probably describing something different, you should look to see if the housing is on tight, check the pcv valve assembly with hose, and any number of vacuum hoses that are a part of the air cleaner housing of that type of vehicle. Also don't forget to check the o-ring gasket that seals the aircleaner housing to the throttle body. good luck.