How to unclog heater core
All you'll need is Acetone, hose clamps, and an electric pump or a tank heater, make sure the pump is designed to circulate fluids other than water. Disconnect heater hoses and clamp each line to the pump, one line on intake, leaving other line free. , make sure other ends of heater hoses are leading to heater core. Next, using a funnel, make sure funnel is hire than the level of heater core. Being careful not to spill Acetone, pour into funnel and once full, connect hose to output end of pump, tighten clamp, and turn pump on and check for leaks.. Let circulate for 45 minutes to 1 hour, then swap hoses with each other so acetone flows opposite direction. When finish empty lines and core, use radiator flush to clean coolant system.