I have a hissing sound, not whistle, when I am accelerating. You can slightly turn the wheel and hear it only with your foot on the accelerator pedal. As soon as you let off, the sound goes away. Where should I start to look ? Had it in the shop and they said that it was the hydraulic steering mechanism. Never heard it before when driving. Is it a leak somewhere or what ? any ideas would help.

 

check all your intercooler clamps and air intake clamps

 

I hope I didnt say it wrong, but it is like a shh shh shh shh shh sound when accelerating. I will try the clamps, thanks rich

 

check all real good one of mine blew at the bottom and u couldnt see it only could feel it

 

does it seem related to turning wheel then, or only accelerating. P/S pump on the way out can make a similar noise...

could be boost leak like other said but seems like it would be a constant hissing while under boost. notice any more black smoke than usual or higher egt's? I made a cheap leak tester that pressurizes intake from turbo through manifold that you can pressurize the system with and listen/feel for a leak. do a search for "boost leak tester".

 

I was leaning towards the p/s pump but I am new at all this fun stuff. I am having a rear seat fixed, ratcheting gears on recline are stripped. I will bring it up to them. Thanks

 

Sounds like power steering pump relief valve.

Do a test in a parking lot in first gear, so you have the rpm of the engine up some. Try turning both left and right with the windows open so you can hear better. You can also try the test in neutral with the rpm up to 2200 and turn the wheel back and forth. Both tests will stress the steering but will not build any boost, so if you hear the sound then you have confirmed steering pump/relief issue, if no sound then it could be a boost leak.

Check you power steering fluid level and you may even consider changing the fluid.

 

Did you ever find the issue???

 

I have this sound to when my truck is sitting idling . It sounds like someone is going Shh Shh . I'm replacing the power steering pump and will see if that fixes it .