High pitch engine screech

[vette427sbc]

I did a little work up on my vette this morning (adjusted the valves, and new points on the dizzy) and went for a short 5 minute drive to test everything out. Came back, shut it off, and turned it back on about 5 minutes later. When it started, the motor started making a really high pitched sound. It almost sounds like a whistle, kind of like one of those screeching firecrackers, just about as loud too. It sounds like it is coming from the carb, or maybe the distributor. Its definitely coming from the middle/back part of the motor. It doesnt get louder or sound any different at different RPMS either. Any ideas?

 

[mrvette]

Vacuum leak, check hoses, fittings and carb base gasket for leakage...possible even intake manifold bolts into heads....

if not found, try a dap of WD40 nearest the sound, find it with a rubber hose to your ear, and wave the end around...shoot some WD into/near the source...it will totally change pitch...

Fan belt??

:mobeer:

 

[SmokinBBC]

vacuum leak? something rubbing under the dizzy cap?

 

[vette427sbc]

I guess ill check again for vacuum leaks. Checked the dizzy for rubbing. This is one hell of a loud vacuum leak though

 

[mrvette]

I guess ill check again for vacuum leaks. Checked the dizzy for rubbing. This is one hell of a loud vacuum leak though

Yeh, but I have heard them do uncomfortable loud noises....not every damn day, but a few times.....been messing with cars about 1/2 a century.....:sos:

 

[Twin_Turbo]

Could also be alternator bearing, harmonic damper coming apart and grinding on your timing cover etc. etc.