Its a very annoying thing, but doesn't affect the drivability.

When I am at a stop light, or cruising without the pressing the throttle, the engine whistles. It sounds like a vacuum leak, but I haven't been able to find one and I have been all over the engine. But it is definatley air rushing somewhere (Not an accessory or belt issue) Its got a Holley top end on a 69 Pontiac 350 block.

Any ideas?

 

I would think vacuum leak as well.

Friend of mine had a shot carb-to-intake gasket on his 68 chevelle and had this symptom.

Do what he did: Let the car idle and try to isolate the area where you hear it. Then spray some carb cleaner in that area and see if you can find a spot where the cleaner starts to bubble up...then you have found your leak. Push your finger against the area where you believe the leak is coming from and if it stops, then you definately found it.

Good luck.

_Clark

 

Finding vacuum leaks are a pain man... but thats all it sounds like. Could also be a cracked or broken vac line...

 

I've had more than one Holley carb-equipped vehicle "whistle".

The problem is most likely a worn throttle blade shaft.

Very common. There is a bushing repair kit for the problem.

jms

 

Easy way to find a vac. leak. Engine on, air cleaner off, spay around the gasket, hoses, ect. with carb cleaner. When the cleaner gets sucked into the engine you will know, and the whistle should stop.