odd engine trouble..possible supercharger related

ok...heres the thing..last week i whomped on the gas a little and i heard sort of a high pitched noise....

now i usually run about 8-9 lbs of boost..i know thats a bit low...but now i run 2-3..and if i floor it i barely make 5...

when the car is on..there is a high pitched..almost cutting noise..like a lawnmower...and it sounds like it's coming out of the blower top or somewhere behind or below the blower...



also my car runs rough and dies...haha..but i need 5 new injectors...so i dont think that is a related issue



thanks a lot

Did the rough running get worse after you lost more boost? Is your gas mileage bad? I'm betting you have a large vaccuum leak, & its making a whistling sound. Maybe check your IAC, thats Idle Air Control.

actually it didn't start dying out at idle till this happened...and my gas was always around 8-12 mpg..but it still sucks...


i dont have my shop manual ..would you mind describing where to find this...pretty please...thank you

May want to check the bypass on the blower. The large rubber hose that goes back into the blower on the back of the engine. It is probably cracked on you and is bleeding off pressure, that is probably the noise you are hearing too. Quick fix for it is some electric tape wrapped around it, but buy the bypass when you can.

Your belt could also be slipping. There is a guage scribed into the face of the belt tensioner that tells you if it is out of range. I'll try to find a pic of the guage for you. Good luck

Get a friend to run the engine while you listen under the hood to pinpoint the noise. Have them shut off the engine and listen for the noise to continue after the engine is shut off for a few moments.

My guess is the big nut on the SC has come loose.

well..i tried checking all the hoses...and they all seem fine...and i'm not sure where the IAC is or how to check it...so i guess i'm takin it in to my guy...and hopefully it won't be too much of a repair...

the thing is..the noise sounds like it's coming from the ABV unit right by the blower...


any thoughts?

Just a thought here, check all your IC connections. I had a similar thing happen a while back. It ended up being the collar nut on the supercharger top. I had come completely loose. I could only must about 5 lbs of boost at WOT and it died at idle. One other indication was very dark smoke coming out of the exhaust under boost. At the time, I was very new to my SC and thought that the supercharger had gone. (Thus I convinced my wife that I could get a new one, a late model one ) Only after I got the new one and went to put it on did I find the problem. Simple, but I felt pretty lousy because I didn't catch it earlier. Check all the IC connections before you go any further. Hope this helps!

After re-reading the original post several times, when you say that it sounds like a lawnmower, I think that is detonation and like 007_SuperCoupe said, you need to check all of your IC connections, and you said that you had, but how did you check them is the Q.
You really need to have the engine running and then spray propane or intake cleaner at each of the IC connections and vacuum connections in the engine bay. Whenever you hear the idle change, it means that there is a leak in that spot.
If you don't deal with the detonation problem, you can damage your head gaskets. Good luck