hey guys! i need some serious help from some serious technical guys with the LNF. Heres my car
2009 Cobalt SS/TC(obviously why else would i post in here)
It has a full hahn exhaust from turbo back.

Ok here is the problem.
I get this really high pitched whistling noise under boost. and only under boost. At first i thought it was the exhaust. So i contacted Hahn and spent my hours talking to Bill(great guy and great help) we determined its not the exhaust. So i take it to the dealer. They say "its the Micky Mouse Exhaust) that i put on it.
Does anyone have any ideas or has someone else had this particular issue?
Its getting super annoying and super loud.
It sounds likes its coming from the location of the turbo. Any help, ideas, tips, things to check for, ANYTHING

PLZ

 

CP Leak.

 

By that i assume......Charge piping?

 

yea it sounds like the charge piping, check it to make sure its not a boost leak, my clamps have popped off a couple times when i first got my car, it was a pain in the ass

 

Yes. Check the CP fitting at the turbo. It is likely leaking.

 

I had a very high pitched whisle with the stock hot side CP and I swore it wasn't leaking anywhere. Replaced it and no more whistle.

 

I check my clamps often because silicone compresses over time. I had a small leak in my hot pipe right at the turbo until I tightened the clamp again.

 

The worst part is the dealer knows its not the exhaust, and that is why nobody is buying Chevy... Yea deff sounds like CP

 

mickey mouse exhaust...yeeeaaaahhhhh... they are pretty ignorant.

 

did it start when u put on the exhaust? if so, tighten the bolts more, if not it does sound like charge pipe. Tell the dealer if thats a mickey mouse exhaust then gm's is mini mouse exhaust. lol :P on them ( couldt think of anything worse than mini, sorry for the lameness. )

 

Yeah stealerships don't give a **** about your car

 

When I took out the intake snorkel in the fender before I put my CAI on, it made a loud whistle.

 

Thank you very much guys! i get the car back tomorrow! and i will def check everything out.

 

i had an issue a few weeks ago, mine would do it only under boost as well. it was more of a fluttering sound rather than whistle. where the shift cables go through the firewall, there is a rubber flap thing around them, and that was being held open

 

What exactly is a Mickey mouse exhaust?

 

Well gents. I tightened the clamp around the turbo. and took it for a spin.........Noise is still there.... Its really annoying! but it goes into winter storage in November so i'm not going to **** with it anymore. Im getting the Hahn Charge Piping in the spring. So i hope that will solve the problem.

Now the sound has graduated to a whistle with a flutter in it. You guys still think is CP?

 

i don't know you, so dont' take this personally. but are you sure it's not the sound a turbo makes under boost?

 

im 100% postive its not the turbo. Ive been a turbo maniac so i know the distinct sound of them. it all started after they did that clip update for the boost tubing

 

Check your charge piping for a hole.

 

did you check

 

Put the stock exhaust back on and take it back to the dealer and tell them it's still making the noise. Then inform them that you're filing a complaint against them with GM.

 

Boost leaks sound like whistles!

 

Where am i going to look for this boost leak?

Next time i can get a jack under it you know i will :-)

 

Have you possibly thought it is the down pipe if the flex section has broken inside it will cause this noise!!!!!!!!!!!!

 

See i would try and figure this out.... but i no longer have the stock downpipe to compare too