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strange turbo whistle from drivers side

2598 Views 7 Replies 6 Participants Last post by  djcheez
replaced head gasket a few months ago and changed from ATT tune to non turbo tune. since then i have noticed a turbo whistling sound on the drivers side while drivng. It always starts at 7psi. To me it sounds like a vaccum leak that is somehow connected to the turbo, it sounds like its coming from a very small area on the drivers side. The sound increase and decreases as boost goes up and down beginning at 7 psi

Any ideas? thanks
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Sounds like there is a boost leak. I built my own boost leak tester using some ABS plumbing parts. I installed a valve stem into my ABS plug. You put the plug into the boot coming off of the turbo and then energize it with regulated air...then start listening for air leaks. You can spray some soapy water on the places you think that it may be leaking. Tighten or replace clamps, bolts and gaskets till you have no leaks.
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I use a regulator and start testing around 20 psi and then go up from there. I go about 20% higher than the highest boost pressure that the truck will see. This should keep the couplers from leaking if there were any boost spikes. I was surprised to find more than one leak on my 08 truck...I upgraded the couplers and all the clamps and it worked perfect afterwards.

Here is a picture of the plug I made.

Some of my buddies made a test plug that fits on the intake of the turbo. When you remove the the stock air intake you can see it. It might be easier to test going through the turbo.

Hair spray can help to seal the couplers to the pipes and also make them stay on under high boost.

Good luck!
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