Extreme blow by on a 6.9

[idibeast]

So I recently installed a Turbo on my 1986 6.9. The Turbo didn't come with an internal wastegate, so I purchased a cheap external one. After several hours of work and custom fabrication to get the Turbo to mount in the bed (long story), we finally fired it up. After driving for about ten minutes, something failed in the wastegate and the Turbo shot to 20 psi. We noticed a slight drop in oil pressure and pulled over to check it out. All I can say is oh my God, the Turbo created enough crankcase pressure to blow the dipstick out and lift the tach sensor, and send oil everywhere. Also the amount of blow by was insane. I was wondering if any of you out there had any idea what needs fixin. That's one thing about these idi's, they can't tell ya what hurts.

 

[Knuckledragger]

Does the truck still run? Is there oil in the coolant? When properly installed, there is one way for the turbo to affect the pressure in the crankcase. That is through the combustion chamber. That means that a piston has melted or broken, you have broken rings, or the head gasket has let loose and the pressure is traveling through the oil drains. Or something else. With all that you have described, I cannot imagine a benign issue. I am also presuming that you mounted the turbo on an engine that had not been specifically prepared for it (studs, shaved pistons, etc.).

Upon further thought, it is also possible that the oil drain for the turbo or the wastegate has affected the crankcase pressure, although I am not sure that the wastegate has any reason to be connected to the crankcase.

Broken CDR valve?

 

[gonecrazyi]

Probably never moves the cdr.

 

[Dsl_Dog_Treat]

Crankcase over pressurized tells me that the CDR was blocked off and not relocated to allow the engine to breathe.
Prolly puking oil past the bushings on the turbo into the exhaust downpipe too.

 

[idibeast]

The engine still runs great and actually drove home after we disconnected the Turbo, and no I t wasn't studded but the wastegate was set at 10psi. Were is the cdr valve located on these engines?

 

[Dsl_Dog_Treat]

Stock CDR location is at the back of the intake and tuna can shaped. There should have been an adapter to relocate it.
What turbo system did you get and able to post a pic of the current setup?

 

[Knuckledragger]

Maybe I was thinking too hard and the pressure in the crankcase has nothing to do with the turbo, at least directly. If there is no CDR, the pressure will build up and start popping loose parts out, like the dipstick and valve cover gaskets. If you don't have one, you can run a road draft tube to manage the pressure.

 

[Black dawg]

what do you have for crankcase vent? tell us more about this turbo.