QuestionI have a 5 ton D500 with a 318 engine. The engine was rebuilt in 1993. The truck was put in storage in 1994 then run again for another year and stored again pretty much till now. I think the rebuild has about 5000 miles on it. I recently fired it up and it ran great. Real smooth, no vibration, good as new. But I noticed the temp start to climb so I shut down and checked the radiator. It was low. But there were no stains or leaks on the ground. I put a gallon of premix in and went for a little warm up drive. Everything seemed OK until I pulled the dipstick. Yikes! - Grayish white, and four times over the full line. I kind of doubt I have an intake manifold gasket leak or a head leak because the engine starts easily and runs smooth. Would you agree with this or should I throw a vacuum gauge on it? How about compressions check even though it runs great?
My suspicion is the timing cover that routes water from the water pump to the block. It may be made of aluminum and may have corroded due to little or no antifreeze during storage. The intake manifold radiator hose connector is aluminum and that rotted out around the gasket seat about 2 years ago and was replaced.
What recommendations would you have to best target the problem prior to committing to any one area of disassembly?
If it is the timing cover and I can get it welded or resealed depending on the condition, would it be safe to use the same timing cover crank shaft seal if it’s undamaged?
Kinds Regards
David
AnswerHi David,
All of that is pretty much immaterial at this point since the color of the oil is "grayish-white". This means the water and the oil are well mixed and well emulsified which means it has been running through the rods and main bearings for some time. This usually damages the bearings, not to even mention cam lobes. Dark brown is the first signs of coolant in oil then light brown to tan and on to gray / white. At best you need to plasti-gauge the rods and mains. .001 to .0015 on the rods is good with .002 as usable and .0015 to .002 is good for a main with .002 to .003 as usable. Then look at all of the lifters and cam lobes.
Another reason it is not important where the leak was at this point is that this emulsified water / oil is coating all of the surfaces inside the engine and just about impossible to clean out without a total tear down.
Any of the possible leak points could be your leak which can be found on a complete tear down. Head gasket being the most common and intake manifold running a close second. Remove a valve cover to see what I am talking about, that is how every inch of the inside of your engine looks now. That gray-white stuff is not a good lubricant even though it feels slimey.
I wish I could paint a nicer picture but can't.
Howard
