Q&A

so the deal is my thermostat stuck causing the truck to overheat so i replaced it. after replacing the thermostat the truck would overheat when at idol or speeds under 40mph and the heater would go cold. i took the truck to the dodge dealer and they pressure tested for leaks and found none and burped the system. a couple of weeks later the truck started the same issues again (overheating at low rpms) the other day i got in my truck for a short trip and the truck ran just fine, i even let it idol for a while and no overheat and not cold air. so what is causing it to intermittently overheat?