Hello fella's, I'm completly lost here I have tried sealing up all possible air leaks. I check the bearing's in the turbo seemed fine. I do not know what to do next. Once I hit about 5 PSI on my boost gauge I get a sound ( sounds kinda like when you install a new radio and you get enigne noise from the radio and it hummmms through the speakers) Also it will only do it if the truck is under a load such as driveing down the road etc. If I free rev in park and hit 5PSI it does not make the noise. Any tips or hints would be of great help! Thanks

not to sound crazy but are you sure it isnt just the whine of the turbo from spooling up just a thought

Hello fella's, I'm completly lost here I have tried sealing up all possible air leaks. I check the bearing's in the turbo seemed fine. I do not know what to do next. Once I hit about 5 PSI on my boost gauge I get a sound ( sounds kinda like when you install a new radio and you get enigne noise from the radio and it hummmms through the speakers) Also it will only do it if the truck is under a load such as driveing down the road etc. If I free rev in park and hit 5PSI it does not make the noise. Any tips or hints would be of great help! Thanks


I don't mean to hijack your thread but this got me thinking. If I free rev my truck in park, my boost gauge doesn't move. I can tramp it to the floor and my gauge still shows 0. It only registers boost when under load. Is this just my truck or ???

I was having a similar (i think) noise and it turned out to be the clamp on my downpipe wasn't tightening up all the way. I took it off, ground out the center a bit and now its as snug as a bug in the rug. Boy that sounds lame, lol!

I had the exact same problem when my engine was replaced, took it back to the stealer, and they replaced the upper plenum gasket, problem solved.

Vin

I too had the same issue after tapping in the boost gauge. Took upper plenum off and saw where the seal had broken and sooty (EGR) air was passing over/under the gasket and man did it howl like that! Cleaned metal surfaces really well and placed a new gasket...prob solved.

it really just sounds like your describing the turbo spooling up sound. Is it a different sound from the usual spool sound or has it replaced the spooling sound?

Its not the spool of the turbo, The turbo spools fine until 5 PSI then it changes and this high pitch whistle over takes the turbo. It is a noise that just started a week ago. I am going to try to replace the upper intake gasket. I'll keep ya posted

I developed the same noise. Just haven't gotten around to it yet. Too busy fixing the rear heater, starter and battery cables. Mine comes on at a higher boost level but it's definitley not the turbo. Let me know if the gasket fixes the problem. Maybe I'll change it when I do my injectors.

mine was similar, i was a more raspy whine, kinda like a supercharger noise..

Its not the spool of the turbo, The turbo spools fine until 5 PSI then it changes and this high pitch whistle over takes the turbo. It is a noise that just started a week ago. I am going to try to replace the upper intake gasket. I'll keep ya posted

I got the new plenum gasket installed today and it did not take care of the problem. Any other idea's?