Recently we decided to turbocharge our 1967 MM G1000 Vista (diesel). In order to provide a sufficient oil return line for the turbocharger we removed the oil pan and drilled and tapped the side of the crankcase so that the oil draining from the turbo would enter the engine above the oil level in the pan. Everything with respect to the turbocharging setup went relatively smoothly but ever since we removed the oil pan and did this work a leak has started somewhere in the bellhousing and we cannot get it stopped. We originally did not gasket glue the new oil pan gasket and assumed that the oil was coming out just below the crankshaft rear engine seal retainer as it seems to be recessed (set up) about 0.050? higher than the bottom of the crankcase. Considering this, we removed the oil pan and made a new piece of gasket to fill the gap below the crankshaft seal retainer and then we gasket glued both side of the new gasket. I felt very confident that we finally solved the oil leak issue but just the other day when we put everything back together and tried running the tractor the leak started again!!!
A couple key things I should note are, 1) we did plug the positive crankcase ventilation tubes on each cylinder head just as the tech manual suggested was to be done for all turbo installations. 2) The oil leak does not occur instantly. It takes about 15min of running before it starts and when it does it is a constant stream of oil that comes out of the inspection plate at the bottom of the bellhousing. 3) Upon our first attempt at start-up after we installed the turbo, we did notice that the oil pressure was running up about 55-60psi where it was supposed to be set to about 40-45psi when running wide open and warm. We did not run it wide open but the pressure was running high until we set it back after a few minutes of running the engine. Lastly 4) we did not have any issues with leaking oil in this area prior to the turbo work and oil pan removal other than a bit of seepage in the bellhousing which seems to be typical of most engines this age. I should also note that this engine was completely overhauled/rebuilt from top to bottom by a reputable engine machine shop approximately 10 years ago and we might have put about 100hrs a year on it since then.
I am not sure if the rear of the oil pan is the cause OR if it is the rear engine seal (if so what would have caused it to all of a sudden give trouble) OR, I have been told that it could be the camshaft plug but again what would cause this to occur? Any assistance at all would be greatly appreciated.
A couple key things I should note are, 1) we did plug the positive crankcase ventilation tubes on each cylinder head just as the tech manual suggested was to be done for all turbo installations. 2) The oil leak does not occur instantly. It takes about 15min of running before it starts and when it does it is a constant stream of oil that comes out of the inspection plate at the bottom of the bellhousing. 3) Upon our first attempt at start-up after we installed the turbo, we did notice that the oil pressure was running up about 55-60psi where it was supposed to be set to about 40-45psi when running wide open and warm. We did not run it wide open but the pressure was running high until we set it back after a few minutes of running the engine. Lastly 4) we did not have any issues with leaking oil in this area prior to the turbo work and oil pan removal other than a bit of seepage in the bellhousing which seems to be typical of most engines this age. I should also note that this engine was completely overhauled/rebuilt from top to bottom by a reputable engine machine shop approximately 10 years ago and we might have put about 100hrs a year on it since then.
I am not sure if the rear of the oil pan is the cause OR if it is the rear engine seal (if so what would have caused it to all of a sudden give trouble) OR, I have been told that it could be the camshaft plug but again what would cause this to occur? Any assistance at all would be greatly appreciated.
