Hello guys, about 2 months ago i finally dropped in a good set of twins with no shaft play on either side. Some of my vacuum hoses were not connected or incorrectly connected so today i adjusted them and also found the pipe that hooks up with the y pipe to the rear turbo was not bolted down properly, so i tightened them and no more wiggly ness. Now i went to test drive it and my primary turbo is now coming online properly, at WOT 7 psi i hear a loud dental drilling sound whining coming from around the turbo area. she also threw very light black smoke from the exhaust but she didn't sound like she was choking or anything. She tends to burn oil on high rpms.

But back to the point, any idea what this drill whining sound is at high boost?

 

That drilling noise is the compressor wheel grinding itself into the housing or some sort of foreign material is getting eaten by the turbo. You need to disassemble to investigate before they grenade or send whatever it is into the engine and ruin it!

Vince

 

Do you think a boost leak can cause this noise as well?

 

Boost leak is normally a whooshing/hissing sounds.

The "drilling" noise seems it would most likely be from the turbo.

 

The "dentist drill" is the long acknowledged sign of a dying turbo. Repair/replace before it takes out your motor. I had a turbo shaft go on track, and it dumped practically the entire oil supply at 70psi into the exhaust, and sent shards into the motor that ruined housings and rotors.

 

Pull the turbo inlets off and y pipe, and inspect for sings of metal/abbrasion.

 

i just want to update this thread in case anyone is having similar symptoms. I know in Angels case and mine that the turbos are fine.

It turns out that there was an intake leak right off the turbos for both of us, somehow the lower nut came off my primary intake elbow. I added a nut and tightened it up real nice like this time(lol) and all is well.