Hey guys,

My car is making a weird sound when boost kicks in... It sound like someone is under my hood pulling a real long tiny zipper quickly.. the boost is strong its not tapering or nothing... the sound amplitude is proportional to boost...

-What did i do to try and rectify this?
Checked all the intercooler connections for leaks checked all the vacume lines for leaks.

Garage tells me the turbo is on its way out.. no play on the shaft or anything..
the blades may be touching the housing he said.

It's weird the car had no problems whatsoever before it went in to get the cams and headstuds installed..how come this happens all of a sudden...

 

Have you done a boost leak test? I have had a similar sound before on 2 different occasions.

1. My silicon coupler didn't seat well and I didn't tighten my Tbolt clamp tight enough.

2. I had a small tear on a crap hose on my hot side tubing that I used temporarily before I redid my I/C piping.


Did the person actually make a visual confirmation that "the blades are touching the housing" when he/she told you what might be the problem? I would make a visual confirmation myself...remove the intake tube and check. It will be obvious if the fins have been making contact to the housing.

 

^ We didint do a leak test which i think is a good idea.. I will need to sort something out tonight...

 

He said the hotside so it would be difficult to see...
In anycase I will buy some appliances and make a boost leak tester and check it out at home...

 

I would think that you would not be boosting like normal if you had a blade to housing issue.

 

Are you sure the sound is correlated to changes boost and definitely not RPM? Just playing devils advocate here. May be something that is just out of place rubbing against a moving/rotating part.

I will also second what 4-G said about a possible tear in a coupling or even something that is lodged in the intake system somewhere. Is the air filter in good shape? Possibly a piece of filter material coming off? Just throwing ideas out there for you.....

Good luck,
~Tom

 

I changed air filters... its defo boost related... The boost is strong and doesent taper so a damaged turbo isint too convinicing at this point in time...

 

check your turbo....just pull off the intake ans see if theres any shaft play...

it could still boost fine, for now.

 

+1

 

BOOST LEAK TEST> that is something you can do in 3 minutes in the driveway to knock the possibility of a leak out of the equation. i would also remove the intake to see if there is any play or wether the blades are touching myself........just my 2 cents though