m R g S r

Alright, I have a b16 a block, p30 pistons and a p72 head with a venom intake manifold, stock injectors, stock throttle body. There is a very loud high pitched squealing noise, and i dont know where its coming from. i am positive that its vacuum related, because when I shut off the car, the squeal will slowly die away, directly as the needle on the vacuum gauge drops, and when it hits 0, the noise is gone. i cant seem to find it, i replaced the IM gasket, applied hondabond when I put it on, and i replaced the injector seals, throttle body gasket. Also, when I'm driving, if i am in say 3rd gear going slow, i can hear the noise (because it's in vacuum) and when i floor it (now vac gauge shows 0) the noise is gone.

I am almost positive that it's vacuum related, because when all the engine components stop moving (when i turn the key to the off position) i can still hear the noise, and it slowly dies off, as soon as there is no vacuum left in the intake manifold.

I removed the IACV and taped up the holes, because I thought that was making the noise, but even with that removed from the intake manifold, it still whistles or squeals.

What else can I check that is related to vacuum? All I have connected is a boost gauge (vac whatever) fuel pressure regulator, brake booster, and thats about it. Here is a pic of it:

m R g S r

I think that leaves the throttle body right? and suggestions? I did replace the gasket, but didn't use hondabond, because I didn't think I needed to.

sporkcrx

I dont know about others, but I dont use hondabond on any of the gaskets for the tb and intake mani. Can you try to listen and pinpoint about where the whistle is coming from with the hood popped and idling?

m R g S r

I tried, but it's really loud, and it sounds like somewhere near injectors/valve cover/throttle body. I thought it was the iacv on the rear of the intake manifold, but like I said, I removed it and the sound was still there. I'll try replacing it tomorrow, because I'm getting code 14, which is iacv. Also, will not running a knock sensor make the car feel a little laggy?

Rory Breaker

Play with some vacuum hoses around the manifold, specifically under it. If one of them has a small gash or is pinched oddly, it will emit a "squeak". While the car is running, just stick your hand under there and play around with any vac hose you can get your fingers on and listen for changes in pitch.

m R g S r

I found it. It was the throttle body. One of the bolts wasn't tight, but that's because the threads were stripped. I applied hondabond and it's quiet now. Thanks for the help thou.