My 2004 Mazda MPV with slightly over 200,000 miles has been experiencing some cooling system problems for the last 15,000 miles. It has been slow to get up to operating temperature and the heat output is low. The problems do not seem to be outside temperature related. Shortly after the slow warm-up problem started, I started experiencing coolant loss. This problem turned out to be a cracked radiator that was replaced, along with the original thermostat and the system was flushed. The loss of coolant was stopped, but it had little or no impact on the slow warm-up or low heat problems. Any ideas what the problem might be?
BTW, this car has a separate rear seat heating and cooling unit.