Bought this car used with 46000 miles about a year ago. THis Fall I noticed when I put the heat on at times there would be no heat. Then later I noticed the temperature guages would go up and the check engine light would come on. Took the truck in to the dealership and had the thermostat and the radiator replaced. Things worked well for a couple of weeks, then the same thing happened all over again. Took it to a different shop and they replaced the water pump and flushed the coolant lines (said that orange bottle kind tended to create clogs). After that the air conditioner did not cool. Now today the same thing is happening with the overheating as before. Any suggestions?
Remove the pressure cap from the coolant reservior. Start the engine and watch the coolant in the reservior. If bubbles begin to appear in the coolant, the most likely cause of the problem is a failed head gasket.