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Time for another round of...WHAT'S, THAT, SOOOUND (the turbo edition)

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Hey hey everybody! Im back! Sold my 2011 GT last year, just bought an 07 limited 5 speed with 115k yesterday! The good - mechanically the car feels great, good maintenance history, etc etc. The bad - hammered with hail, other exterior cosmetics.


It currently has an SPT intake, and SPT catback (from the previous owner, before this gentleman that sold it to me).


Onto the sound! Well, so far, from what I can tell (no AP yet, coming soon) from the ear test, it's only making this "squealy-balloon air release-pig on helium" sound when it's under load, and in boost. If I'm gently rowing through gears, nothing. In Intelligent, Sport, or Sport sharp, getting on it, you can hear it.


SO, without further ado...WHAT'S, THAT, SOOOOOOUND!!!!! (the possible bad turbo edition)



Essentially, I'm planning on upgrading to a vf52, fuel system, dp, and some other stuff. Just trying to figure out if I need to keep her parked until that point in time.


Thanks for the listen...I have an appointment with a buddy of mine's shop next week, thought I'd get some opinions!


Cheers, and it's good to be back!!!


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Here's a simple boost leak testing method from Tuning Alliance. It may require a proper one but this should point out anything major.


Leak Test:

You will need, a flat head screw driver and a plug for the intake 2.75” OD (aerosol can, spray paint etc will work). You remove your intake from your inlet tube, then insert the can into the coupler just in front of the inlet tube. Next you remove the vacuum source line from the by-pass or blow-off valve and blow into the source line (which connects to the manifold). Try not use above 5 psi because the inlet, pcv, and valve breathers will be under pressure and could pop off or generate a leak. The breathers normally do not see boost pressure. I typically blow into the line with my mouth (lungs) because its quiet and easier to hear air coming out of the system. Once all leaks are contained I blow into it and put my thumb over the hose for 3-4 seconds, then release my finger, and it should still contain some pressure and you can hear it hiss back out at you. A smoke test is another good way to locate leak sources but a smoke machine is needed.

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Thanks Max, and Henhead, I might give that a try before I head over next week!


Fjuan, yes indeed, only under full throttle! I'll check that when I get home today...was that the same kind of condition you had?


Yes, under full boost all that pressure will squeeze from a loose clamp and cause that farting sound, my kids laughed every time it happened.


Normal driving no sound, only under full boost. Check all your intake hose clamps.

My wife's balls are delicious.
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Can confirm the loose throttle body hose created a similar sound for me. My '08 had 85K miles when I checked the TB hose - it could be wiggled with little effort after removing the TMIC. Hose clamp for the inlet to turbo was also loose. Both of these simply worked themselves loose over the years & miles.
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