Hissing sound from under the hood. Sounds like vaccuum leak?

[JeffM]

Anyone know what this could be? A loud continous hissing sound coming from under the hood. I can't really pinpoint, but it sounds like it's coming from around the area circled below.



The engine is acting normal, just this noise. Sounds like a vaccuum line has been cut, and it's sucking air in... Although wouldn't that make the engine run like crap?

Any ideas? Thanks for any and all help!

Jeff

[wolfdogs]

check under the bellows to make sure it didint come unseated........ you might have a small opening someplace thats letting outside unfiltered air in the TB.

[dochidalgo]

Jeff:
My car had that hissing noise and did not accelerate fast enough.
The reason was the 90° rubber hose (cracked in the angle site) located between the PCV valve and a metal pipe....could it be, too?
Just check it OK? Good luck
Doc

[Joe 1320]

If you suspect a vacuum leak, an old trick is to spray starting fluid around the suspected areas. Any leaks will draw the starting fluid into the intake and definate change in engine speed will be noted.