Turbo whine
 

So to start off, when first ran, my new turbo had a small leak on the compressor side. I decided this was not a big deal, its pretty small (i dont have a cdr so it isnt that). Now that i have almost 5k miles on it though, the turbo is whining when under slight boost. Started about 1k ago (3500 miles or so). It wont do it at idle, but will do it with just reving up the engine enough to make 1-5 psi, over that, and i think the whistle drones out the sound. Its very annoying, for a good long while i thought it was a bushing or bearing in the trans, as you normally noticed it at low engine rpm. Since then however, its gotten worse and ive been able to pin it to the turbo not the trans. Response and boost havent changed, and both are good. Does this sound like a bearing issue? Never heard of a turbo making such a noise before, so im kinda stumped. Havent checked free play since installing, i guess i should start there.

Since the sound is evident even when revving the engine you could use a mechanics stethescope to listen to the hot and intake side of the turbo. Have a buddy rev the engine while you listen. If one of the bearings is going south hopefully it will be pretty obvious.

Well i got a screw driver, i guess i could give it a listen

when was the last time you changed the air filter?? remove or replace it see if sound changes...

Its a cheap washable filter, i washed it when i put the engine in and looks great, will give it a shot, but i dont think its air related, its more turbo speed realated it seems. For instance, it will do it at 1500rpm making 4-5psi, and the same noise at 3000rpm making 1-2psi, has to be something to do with load on the chra or speed im thinking.

Side to side play is fine as long as the compressor wheel does not contact the housing, end to end is where problems start.

Also are you sure it's not a small boost leak? They normally let out an almost high pitched squeal. Sealing the hat to the intake is supposedly a common problem, a 4 barrel carburetor gasket for a 460 from autozone will fit the idi intake. There both 5" iirc

Yes im sure, nothing big enough to worry about at any rate. I dont have the factory intake, i have the R&D intake.

When I installed my turbo (Banks) I had a whine as well. Mine was caused by air leaking past the cover plate/gasket where the CDR was originally located on the back of the intake. I'm not sure if the R&D turbo has the CDR mounted differently, but that might be one place to look. New gasket and tight bolts eliminated the whine for me.

Out of curiosity have you checked the tightness of your boots? I have heard of slight boost leak from connection points causing a whine, but That tends to be at higher boost pressures, but it is a thought.

All of the boots are tight, and i dont have a CDR. Since i installed the gapless rings i went with a road draft tube. I had a boost leak when i first put it together, and it would "squeal" when i got over 15psi or so. This only does it at low impeller speed / boost.