I have a turbo II with a fresh rebuild w/ medium street port, 1500 miles on the motor... s5 turbo, 3in dp, emissions removed. Still has power steering and AC.

I was driving down the road and i needed to get over a lane but the ******* next to me would let me over, so i downshifted into 3rd and 3/4 throttled it until about 5grand and shifted into 4th. After i turned my corner i noticed that my car was making a very high pitched squeeling noise if i wasnt pushing on the gas.

So far i've checked all my belts, pulleys, hoses, and replaced the seals around my fuel injectors because they were leaking and i thought that might have been the problem. It fixed some of the problem but not all of it. There is still a high pitched squeeling that sounds like something is being killed under my hood.

I'm only running 5 pounds of boost because i was in my break in period.

Again the noise is only in vaccume.

PLEASE HELP!

 

Maybe a hose has a small hole or crack and is whistling. When you rev it more it is too much air to make a sound. Just a thought...

 

yeah when you rev the car there is no noise, but idling or just crusing not accelerating the noise is there.

We've checked all the hoses.


Heres a video of the noise.

http://smg.photobucket.com/albums/v1...PICT0001-1.flv

 

cracked or broken intake manifold gasket, mine made a very very similar noise to that when it happened to me

 

yeah i think we are going to check that, its loud as hell like retarded loud.... i have narrowed it down to something along those lines... i am going to mist it with carb cleaner tonight to make sure it a leak. but its coming from under the manifold for sure.

 

+1

Check upper and lower intake manifold gasket.

 

jeez that is loud. I have one of these intake pressurizing tools and it helped IMMENSELY.
http://www.boostpro.net/prodtester.html

This one is the best for doing it on your own, but only if you have a decent sized air compressor or it's at least far enough out of earshot that you still can hear the leaks. I've found it's also a decent way to test how much intake pressure your current setup will hold together under, just make sure you have someone look at your in-car boost gauge or read a diagnostic gauge from wherever your in-car gauge would read from as the tester will probably read a little higher due to it being right at the start of the intake. Good old fluid dynamics.
Boost Leak Tester (Gauged)
3" Diameter)
With Male Compressor Coupler
$20 + $4.60 shipping

Also, I was under the impression that boosting at all during early break in was inadvisable, but it may not have made any difference and is simply a precaution. Obviously it's too late anyway, but just thought I'd mention that.

 

i've heard that on an 88 n/a. we tore into it and found no gasket between the UIM and LIM, some people's kids..... +1 on the intake pressurizing tools

 

we found it its the lower intake gasket.... i hate pulling the turbo to take that damn thing off..... oh well. we should have it done here in the next few days

 

anything yet?

 

Yeah the lower intake gasket was fucked for some reason. We just replaced all my gaskets when we did the motor rebuild so, idk what happened.