12. March 2012 22:06
Hey folks, this is AJ, doing another blog on the wonderful 6.0. If you own a 6.0 or work on a lot of them chances are you have dealt with a cracked up-pipe or y-pipe. To better understand this exhaust system take a look at this diagram.
As you can see in the picture the exhaust is carried from the manifolds up the y-pipe and up-pipe to the turbo where it spools the turbo then exits the turbo to go out the tailpipe. These pipes are bolted to the manifold and turbo and since these pipes have to deal with constant pressure there are 3 sections on the pipes that "flex". These joints allow the pipes to move so they do not crack and explode open causing a massive loss of power and boost. With the constant pressure and movement these pipes crack over time. (A lot!) The typical symptom of a cracked y-pipe is a loud hissing sound and a loss of power as well as smoke and black soot under the hood. In the pic below is an up-pipe/y-pipe assembly that had completely broken apart at 2 of the flex sections.
These pipes can be a nightmare to change and the design is still used on the 6.4s and doesn't seem to have been updated since we've started seeing a LOT of cracked up-pipes in the 6.4s. The trick we use for the 6.0 is to remove the turbo and remove the 4 bolts and nuts that hold the y-pipe/up-pipe to the exhaust manifolds. Then remove the clamp that holds the up-pipe to the EGR cooler. We then remove the pipes together as one assembly. This seems to be easier than trying to remove the 2 bolts and nuts that hold the y-pipe to the up-pipe. When you install you're new y-pipe leave the bolts loose at the exhaust manifold until you connect the y-pipe to the turbo. This helps you get the y-pipe seated to the turbo (a common problem when installing a 6.0 turbo). This job is pretty straightforward but does require a lot of patience and a good 10mm wrench wedged in strange places. HAHA when you replace your y-pipe you'll understand. Alright guys hopefully you never have to change one of these pipes but if you do now you understand how they work. Thanks, AJ