I have a 2004 Dodge Cummins 4x4 6 Speed . I have a High pitched whistle or tweeter at 2000 R.P.M. Thought it was a turbo brg. so I had it rebuilt.While I had it apart I replaced all the turbo/intake boots and still had the same noise. Replaced the wastegate controller with a banks big head, still the same noise. Pulled the intake piping off at the turbo and intake and pressurised to 30 p.s.i. to test the innercooler, it holds press fine, no leaks.
Any body have any ideas. Thanks

 

Possibly a leak on the exhaust side? Drive pressure?

 

Sounds like blown out exhaust manifold gastket to me. A few months back I had truck come into shop with whistle noise. Several other shops were unable to fix, turned out to be exhaust gastket blown out. Replaced gastkets now I have a happy customer.

 

Thanks, I'll check that.

 

Guys,
I'll Keep you posted . I ordered parts from Cummins and they sent everthing except exhaust gaskets. It will have to wate until my next day's off.