AllPlay

All of the sudden my truck is making a sound between a Pratt & Wittney engine and a tornado siren. It is coming from the engine compartment but I do not think it is the turbo. Letting the engine cool to get a closure look. Mostly a bearing sound when boost starts to build. Can not hear it at idle. Truck seems to run fine. Boost still builds and Pyro seems O.K. Running 65 mph with 600 to 700 degrees. Any ideas???

Adaminak

My first look would be in the turbo. If you can wiggle the input shaft side to side, you've probably found the problem. Another possible area is the air-direction vanes inside the air tube between the filter box and the turbo. If one of them has managed to break free, it might be partially blocking the airflow and creating the whistle/whine you're hearing.

AllPlay

Stood on it pretty hard on the way home and the screaming/whistle sound stop but you can hear alot of whooshing sound. I also can only make 20 psi getting in it hard and the needle is jumping around. I checked the bands on the intercooler boots and they where somewhat loose so I tightend them but that did not stop the sound. I will check the turbo for play.

ggnutsc

If your sure it's not the turbo, I'd think about looking at the fan, both clutch and the bearing. With the engine off and cool engine the fan should turn by hand. If the clutch has failed and locked up they will make a lot of noise, especially as you wrap up and accelarate. I have also had the bearing go out for the fan ($160 at the dealer) and it sounded pretty horrific as well. It may be neither of these but at least you can rule out them.

AllPlay

I do have some play left to right but more up and down. I would guess if you feel any movement this is bad. Looking on EBAY I found a couple. Will a the WH1E or the Super Drag EMUSA HX 40 work on my truck? Trying to stay under $400.

Diesel Doc

It sounds like you probably have a hole in a intercooler boot or your intercooler. Take a can of brakecleen or the like let your engine idle and spray little shots at your boots and then the intercooler. If your idle changes you found your leak.

AllPlay

Thanks for the help. The large intake gasket was split. Much better know.

infidel

Side to side play is normal as long as the blades don't rub the housing.
Fore to aft play is bad.

SIXSLUG

I'd use wd 40 rather than brakekleen. Thats an old rodders trick for finding vacuum leaks. I think Brakekleen is pretty flammable.

Kurt

Diesel Doc

WD-40 used to be really flammable. I hate the stuff so I dont know if it still is or not.