MY heat is almost non existant when idling and only luke warm when driving. I have changed the thermostat, flushed the system, and backflushed the system, still no help.is there a way to flush the heater core directly? if so how? also, when i am driving and trying to hold a steady speed, the engine surges and hesitates. i have the check engine light on and the code reads "egr valve insufficient flow". i have changed the egr valve, fuel filter, spark plugs, plug wires, and run tons of injector cleaner through. any help would be greatly appreciated.

I am having the exact same problem on my 94 3.8L tarus.... did you ever find a fix for it? I have no heat at all, and its FREEZING here.

any help would be greatly appreciated.