1st make sure your propane is full and working properly check for spark or listen for clicking check the exhaust port on the outside of rig for dirt/bee's leaves check thermostat
Oh dear, Usually requires major surgery. At the very least head comes off, sump too, rings, bearings and at least cylinder hone, if not bore, and set oversize pistons and rings. Sorry, not good news
One presumes this question refers to an auto engine, and that you are describing water found in the oil. If so, the problem is not a small one. Either the engine block is cracked (most serious) or a...