13. April 2010 17:47
HAve you noticed a lack of power on your 6.0?? If you own a 6.0 or if you've ha to diagnose one then you are probably familiar with the turbocharger system. The turbo on a 6.0 is called a VGT or variable geometry turbo. A quick lesson in turbochargers, a turbo is fed exhaust gases by the exhaust manifold and these gases spin the turbine wheel (the rear blades) which in turn spins the front blades which creates boost. This boost is fed into the intake manifold and simply adds more air to the engine so you can add more fuel thus creating more POWER. That's what it's all about. A turbo has 2 housings. The rear housing or exhaust housing and the front housing or compressor housing. By having a smaller exhaust housing a turbo will spool up faster and create more boost but can create more boost than is needed whereas a larger housing will flow more but will have turbo lag (hesitation before boost builds). A VGT turbo is the best of both worlds. It has vanes inside the exhaust housing that are attached together by a unison ring. A solenoid moves the unison ring therefore moving all the vanes in unison to create a smaller or larger housing giving you more or less boost respectively.Below is a picture of the vanes on the exhaust housing. As you can see there is rust built up where the vanes move and can cause the turbo to stick and cause low boost or in some cases too much boost blowing off intercooler hoses and in extreme cases causing excessive stress on head gaskets. Cleaning the turbo is pretty straightforward but requires attention to detail and care when reassembling. First step is removing the turbo and I'm not gonna go over every step cause it could take a while. Once you have the turbo off mark the housing so you know how they go back together. Remove the clamp that holds the 2 housings together and get a rubber hammer and hit around the exhaust housing to free it from the compressor housing. Then simply take a die grinder with some roloc discs and clean the vanes, unison ring, and housings. If you cut one of the pads down to about 1 inch around you can get in between the pins and clean the housing where the vanes move. It's recommended to use a light coat of anti-seize on the vanes and ring when you put it back together to help prevent rusting. Take the unison ring and move it left to right ensuring the Put the vanes and ring back on and align the solenoid cam with the slot in the unison ring and put the two housings back together. Make sure the dowel and cam are lined up and it may take a light tap to get the housings seated together. Once they are flush install the clamp and torque to 160-in lbs, loosen clamp, then torque to 150-in lbs. Make sure when reinstalling turbo that you have or install the new drain pipe that flows more oil than the old design.
Below is the unison ring which I had already cleaned in this picture. It's important to look at the slots very carefully to check for spots that may be worn out or stretched.
Here are the 2 housings.
Here's a pic of the cleaned housing and you can see the new drain pipe right there.
Thanks for listening everybody and if you have noticed a lack of power in your 6.0 or sluggish response call AJ at 706-255-4161 and I can hook my scanner to it and see what's going on. Or come on down to 441 Diesel.