A flow diagram is needed to determine the coolant paths for that engine. Usually clogs are resolved by backflowing (reversing) the passages in question. If it is a corrosive clog it may be impossible to resolve without removing/replacing part.
Question is whether your heater is getting hot before other parts of system. I have an infrared temp reader from harbor freight $10 that I use to check temps around parts. Like compare top and bottom hose on radiator and heater hoses etc.
Saturday, September 10th, 2011 AT 5:25 PM