My truck is running fine but it sounds like there is an air leak on the drivers side of the truck. When it first happened I was passing a car and it sounded like a vacuum hose come loose. It made a loud hissing sound. Now I have come to the conclusion it must be associated with the turbo. I don't hear the hiss unless I get into the truck and the turbo starts making boost. The more boost is made the louder the hissing sound is. Any ideas?

 

Check the CAC hoses and the intercooler for leaks. Sometimes they can be very hard to locate because they crack in weird places, usually on the bottom. Check the intercooler tank seams for expansion.

 

Get a 4" rubber pipe cap - the ones used to cover roughed in plumbing. Drill a small hole in it and put in a valve stem with schrader valve. Remove the intake from the turbo and put the cap on and apply compressed air - not too much, about 15-20 psi. Listen and find your leak.

 

Plastic intercooler pipe? Check here first......

 

Had same issue. Pulled the elbow off the turbo to hot cac pipe. 1 1/2" tear on the under side.

The whoosing noise is gone and the tire spinning is back! lol