I need some help. I've had some problems in the past with my sister's Expy. It had a coolant leak and unfortunately I could not find it and was too lazy to investigate and ran stop-leak through the system. This led to even MORE problems and I do not recommend anyone ever using this s**t. The leak disappeared but so did the heat. No heat front or rear, pulled the dash out over the weekend and got the heater core out. It was heavy with sediment from the stop leak and of course clogged. I placed a new heater core in the system, flushed the system, flushed with cleaner, and flushed again. I know have a problem where the heater only blows "hot hot" when the motor IS NOT idling, when it has some RPM in it and it blows good and hot. The rear air still not working, assuming that is also a heater core problem. Trying to just get the front in good working condition before tackling the rear. When I had everything out of the heater housing, I checked the blend door and actuator and everything looked great and ran great. Reading through the forum I assume I should just replace the T-stat since its cheap and easy. Could this also be a worn-out-fins water pump issue? Anyone with any suggestions highly appreciated especially since you took the time to read my rambling. Thanks. 
