I have a new to me 2002 DF140 with 1300 hours on it. I don't know how long the motor has sat idle but the previous owner claimed it ran well. I never ran it. I checked the oil and found it to be milky. Not thick, just milky, almost slightly runny or at least a little less viscous than motor oil should be. I checked the oil cooler and it appeared to be in perfect condition with the seal looking new. I pulled the block and one of the block/engine holder bolts near the exhaust port was fused to the block. I was forced to shear off the bolt head. Then the block would not separate from the engine holder and I had to pry at it just to get the block a quarter inch from the engine holder. Then I was able to saw the bolt shank in half and the block was able to be removed. Looking at the block, it all appears to be clean as a whistle inside. The bolt shank that I had to cut appears to have rust around it where it enters the block. The mating surface between the block and engine holder was also very clean except around the exhaust. In that area the mating surface is discolored. I am wondering if the source of my water leak into the oil is coming from this area where the water jackets surround the exhaust. I would rather not have to remove the head, although I understand that it is the next most likely culprit. The lack of major corrosion in the parts of the motor I've been able to see so far make me skeptical that the head has corroded badly enough to leak, especially since it appears I may have located the problem elsewhere. Looking into the intake ports on the head I can see surface rust on the valves, but like I said I don't know how long the motor had been sitting and maybe that is the cause rather than water seeping into the cylinders. I'm not sure how well the motor would have ran if there was water in the cylinders. Do you guys think the exhaust water jacket area is my problem or should I bite the bullet and take off the head to check the mating surface there? Thanks for any help you can give me!
Chris
Chris