I lent my truck out to a friend a week ago and when I got it back I found the coolant level very low and slight signs of oil in the water. First let me say that I'm not trying to lay responsibility on my friend but I think it might be worth noting since it's the first time in a year that someone used the truck daily as primary transportation. Anyhow, on with the story, I found one of the lower hoses to have a small leak when hot so I changed all of the hoses(they were pretty old anyway) and checked compression. Dry compression is between 150 and 160 on all cylinders, I'm not blowing white smoke, and three of the plugs looked good while the number one plug had an excessive gap and showed signs of overheating. I also noticed water spray on the hood in line with the belts after a trip to the parts store and I'm wondering if this can all be caused by a bad water pump? Can a damaged water pump lead to water in the oil or is it more likely a sign of a damaged timing chain cover? How likely is it for a head gasket to become damaged between the oil and coolant galleys but not at the cylinders?