Air Leaking Noise????

[scape]

I just had the fuel block replaced last week for a fuel leak problem and while driving the truck I could hear a sound that is similiar to an intermitent high pressure air leak. I thought it was due to the fuel leak, but after the repair I still have the noise and I still think the truck is down on power.

Anyway, I tend to think it has something to do with the turbo. It only occurs under acceleration and/or under load. At idle I don't hear it, but push on the accelerator and you can hear it going hisss......hisss....hisssss.

Has anyone else had something similiar...I will take it to the dealer tomorrow, but we leave Friday (pulling the boat) for vacation....

[sdaver]

sounds like the waste gate control line came loose look under the plastic 6.6 cover find the 3/8 rubber hose that should be connected to the side of the turbo on a small canister...the other end goes to an nipple on the turbo housing.It has or should have a cheesey pinch clamp on it could have blown off........this would explain the hiss as the system builds boost........good luck..... this would also relate to the down on power because the system would be leaking or bleeding boost