[DeltaP]

I assure you replacing the bad fan motor wasn't a waste of time and money. You just haven't stumbled on the next problem yet. Did you bleed all the air from the cooling system when you replaced the thermostat? Was the thermostat installed in the proper direction? Was it installed with the jiggle valve up? Do you have adequate flow through the radiator? Possible water pump impeller erosion or partially restricted radiator. Need to scan PCM for DTC's.