pcassidy111 Posted July 22, 2012 Share Posted July 22, 2012 My truck was throwing codes P0299 and P0234 and one time went into limited power mode after towing my 11000 pound trailer for 5 hours. Based on prior experience I knew the turbo vanes were sticking. EGR was clean and not P0404. 20K miles ago a new center housing rotating section was installed by the dealer before the truck went out of warranty. I decided that I was going to do a turbo reconditioning as per the Ford TSB's. Last night I cleaned up the vanes and center/turbine sections, installed a new unison ring assembled it an left it on my bench with the exhaust side down. This morning, after reading an updated Ford procedure about applying a thin film of anti-sieze to the unison ring, center section and turbine side I decided to pull the turbo apart again. When I separated the turbo sections (the exhaust side was still down and the compressor side was removed) I noticed oil on the back side of the exhaust turbine and oil in the cutout for the unison accuator pin assy. There was no oil on the bench or exhaust turbine fins, no oil on the unison ring and no oil on the vanes, it was as if you had put the compressor side of the turbo down and squirted oil behind the exhaust turbine and in the cutout for the acuator pin assy. It was not a drop or 2 of oil more like 10-20 drops. I removed the threaded plug above the VGT accuator and there was some oil in there and on the tip of the VGT accuator, dont know if this is normal. On initial startup after repair and during a 30 mile test drive there was no oil smoke. There is a sheen of oil where the accuator pin shaft enters the turbine housing but no drips. Where did the oil come from and do I have a problem? Is there supposed to be oil at the tip of the VGT accuator? I did move the unison ring accuator lever back and forth with the VGT solenoid installed when I had the turbo apart, did I break something? Possible the VGT solenoid or the piston seals? There was no evidence of oil on the exhaust side or the VGT accuator area when I disassembled the turbo. I also notice a slight (longer)turbo lag at WOT from a stop, was it a mistake to use the Ford anti-sieze on the unison ring, compressor housing sliding surface and on the area under the vanes as described in the Ford procedure? THe turbo is still hitting normal boost for my driving, about 10 psi at 2000rpm, 20 psi at 3000 rpm and 28 psi accelerating up an 8% grade-as per the boost gauge on the dash. Using a Snap On scanner doing the boost test at 1200 rpm I cannot get the required EBP,MGP numbers but it may be a scanner problem. This is the first turbo I have reconditioned, maybe I should have just replaced it? Thanks for the help, Pete Quote Link to comment Share on other sites More sharing options...
GregH Posted July 22, 2012 Share Posted July 22, 2012 If the truck is not setting codes, the turbocharger system passes pinpoint test KA, and there are no external oil leaks, then no additional service is required at this time. It's easy to get too close when working on your own vehicle. I had difficulty when I replaced cracked cylinder heads on my own 4.0L Explorer. Drawing the line between "good enough" and "perfection" was tough, and as a result I second guessed myself the whole time. If it were a customer's vehicle instead of my own, I'd probably have done it in much less time... Quote Link to comment Share on other sites More sharing options...
pcassidy111 Posted July 22, 2012 Author Share Posted July 22, 2012 I am going to replace the VGT solenoid because looking at the design I feel there should be no oil behind the pipe plug where the accuator rides on the cam assy. Checked the radial and axial play prior to disassembly and both were good. Is it possible that due to bearing design the shaft seal will leak when there is no oil on the bearings and the shaft is left in a vertical position for 14 hours? Any tailtale signs of oil going out the exhaust side shaft seal? There was only carbon and rust, no brown sand like material in there. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted July 22, 2012 Share Posted July 22, 2012 Is the tailpipe loaded with oil? Is the truck using an inordinate amount of oil? If it ain't broke, why fix it? Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted July 31, 2012 Share Posted July 31, 2012 I have seen this with holset turbos off cummins engines. If you set them on end for several hours, will find oil on the bench under the exhaust housing. In those turbos the design of the seal and shaft it will let the seal leak when in that position with no oil pressure. Have put them back on with no ill effects. Unless you have smoke, or oil consumption I would not worry about it. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted July 31, 2012 Share Posted July 31, 2012 I had one 6.0 turbo leak oil out of the turbine side after sitting that way face down for a few days. Never had any problems with it, never set any more turbos down like that again. Quote Link to comment Share on other sites More sharing options...
Clark Posted August 7, 2012 Share Posted August 7, 2012 Most turbos are only designed to work in a very specific range of angles. The shaft seals are actually pretty similar to piston rings. If the turbo is at too steep angle, then the rings will not be able to seal properly. If the turbo was vertical with the turbine facing down, then oil seeping out of the center section would be expected, but would not be an issue. Some racing turbos are designed with much more elaborate sealing systems to allow running at very steep angles. Quote Link to comment Share on other sites More sharing options...
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