Is it possible for hydraulic fluid to get into the engine oil? I rarely use this back hoe and the engine has always been strong, but yesterday after using it, I shut it down and saw a little smoke was coming from under the hood. So today, I checked the oil after not having changed it for about 2 years (as I said, I use it very rarely) and the dip stick is way, way, way past the full mark. It looks like there is about a gallon or two more oil in there than is supposed to be, but the oil is as clean as new - but I would swear it's hydraulic fluid. Now I added 5 gallons of hydraulic fluid about a month ago before using it at that time - the cylinders all leak so I use hydraulic oil whenever I use the machine, but I never thought it could make it's way into the engine - can it?
Are you sure it’s not diesel fuel?
Definitely not diesel fuel, that would smell and be somewhat purplish. This stuff is clear, and it leaves the same type of film on my hands as hydraulic fluid. Definitely has me biffed.