I have about 90K on this. Two problems: 1. Overheating/using coolant. Used it to pull a cattle trailer with a semi-heavy load up to OH and had to put in 1-1 1/2 gallons of water when I stopped for gas. Ran about 3/4rds hot. On the way back I was much lighter and had to put in about the same amount on half-way fill-up. However, rest of way didn't use a noticeable amount. At that time it was raining, cooler and I was driving slower. After last fill up gauge ran about normal to just a tad hot. I cannot find a leak either by the water pump or anywhere on the radiator at pressure or when left to cool down over cardboad. Don't notice any steam from top of radiator. Could this be simply a bad radiator cap? 2. Engine (gas) has started to sound about like a diesel with valve tapping. Doesn't use significant oil and exhaust is clear. Valves thus appear to be good as far as seating for mileage. Could this just be worn out springs and/or lifters which wouldn't require pulling off the heads for an overhaul? Please keep replies in Kitchen English. I am not a techie.