Mintyhit

Engine runs fine, just this annoying squeak when revving. I tried (very briefly) without the serpentine belt to see if it was a pulley bearing but no dice.... TCT perhaps?


Apologies for the state of my crank case cover.

flanders

Since you heard it in real life, could it be a sucking sounds, like a small vacuum leak somewhere between head and the throttle plate?

Mintyhit

I don't think it is a sucking noise, It sounds more like scraping.... If it was vacuum leak I'd imagine I'd hear it when opening the throttle more than closing it.

rpg51

Try a stethoscope, or a cardboard tube, to isolate the sound to a place.
It seems to be a noise that occurs just as the rpms begin to drop after a rev. Makes you think vaccum - but it doesn't sound like air.