Sporadic overheating

Several things can cause an engine to overheat. Flushing the cooling system is a good maintenance practice, but won't cure and overheat condition. A faulty/sticking thermostat, a clogged radiator, a faulty radiator fan or engine temperature sensor can cause problems, or even a loose/worn/misadjusted serpentine belt can cause the problem. Because its only happened twice, a shop will have to 'catch it in the act' to help determine whats causing the overheat condition.