Oil Loss
 

2 weeks ago, our 99 expy with 4.6, 116k started to have what sounded like a sticking valve when it was first started. With the weather being cold and occassionally having a similar problem with my 95 F150, I did nothing.

We went to West Virginia for Easter (from Cleveland, OH), and Sunday morning as we are heading to church from our cabin up a steep 4x4 road it loses oil pressure and the red light comes on. I immediately let off the gas, and the oil pressure recovers, so I drive another 50' to the top of the hill and shut it off. I check the oil and the dipstick reads nothing. My brother inlaw comes with 4 quarts of oil, and we put all of it in, and the dipstick still reads nothing!

There are no apparent leaks, no have there been since we owned it. It has not been running hot. No oil in the coolant. No color to the exhaust or weird smell.

We get back to the cabin, drain all of the oil and put fresh oil in. (We couldn't get a filter because the automotive stores were closed on Easter.) It takes 5 quarts to bring it to the mid point on the dipstick. The engine is running fine, and the valve knock is gone.

My first question is, what happened to the oil?

Likely scenarios are 1.) it got burned up 2.) it leaked 3.) it never got put in from the last oil change 5000 miles ago. I'm thinking #3 is most likely (my stepsons did it who suffer from short attention spans), but I can't believe an engine would have run that long with so little oil.

Now that I'm back in home I'll do another oil change, and then another one in about a month.

Next question - did any serious damage occur? Can I pull the pan easily to clean out the pan and oil pump?

I'd say that if they forgot to put the oil in all together you'd have noticed it much sooner. They may have not filled it full, then if your's is like mine it consumes some oil over time. Mine doesn't burn it or leak it, I just have to add a quart every once and a while which may have been what happened to yours. As far as damage, it of course is not good for an engine to run without oil so I'm sure you shortened the life span of the engine. I would not worry about pulling the oil pan, just keep the level up, and check it when you travel, or what I do with mine is check it every other fill up

These engines are known to lose oil between changes....mine is a quart low by 3000 miles. Where it goes I'll never know.

My 98 Gator w/ about 150k miles is now consuming about 1 quart in 1500 miles. The blowby is increasing and there is a lot of oil visible in the intake. I believe the cause may be due to an open PCV system. I found last year that the engine was sucking unfiltered air through the PCV due to deteriated rubber connections. Replaced the whole assembly but I think it was too late. The truck still runs great but I have to watch the oil level closely.