Weird "whistling" sound under full throttle

[90_K5 Blazer]

Hey guys, I've got a weird one here...

About 2 days after I developed an exhaust leak, there is an extremely strange whistling sound coming from somewhere under the hood, it sounds like i have a turbo! It's really that loud and high pitched!

The thing is, it only happens when the throttle is depressed under load; if i'm idling or cruising on the highway at 2500 rpm, its not there. Could this have anything to do with the exhaust leak? If yes or no, anyone know what the heck could cause this? Because it' only happens with the pedal too the floor, I doubt its a whining bearing somewhere..

Thanks in advance, it's driving me crazy!

 

[Hogback Fabrication]

It could be intake noise, but if its a recent thing I would look for vacuum leaks.

 

[sandawgk5]

What kind of an aircleaner are you running? When I flipped my factory lid over to make a cheap open element, mine would whistle under throttle do to the air flowing aroung and into the TBI

Dik

 

[90_K5 Blazer]

Hey thanks for the replys,

Well I have checked the intake and looked for vacuum leaks which i though might have been it, but everything looks to be in good order. I actually do have my air cleaner lid flipped over, but i've had it that way for over 2 months and nothing has made any sounds other than the typical intake noise whenever you open up an aircleaner...

 

[Jason4x4]

If your cat is pslightly plugged, then under heavy load it doesn't flow enough and could be whistling theough the leak.

 

[90_K5 Blazer]

Hey thats a pretty good idea, it could be since i just hit 100,000 yesterday, and even if it isn't, i'll finally have a good excuse to cut it off!

I'm still looking for the cause... air cleaner, vac lines, and intake seem to be good, bu i'll have to wait to check the cat... This thing is driving me nuts!