You know how a ratchet wrench makes a noise in one direction? Could something be hanging inside the fan itself? The stutter movement I think is normal because of the stronger magnets in todays motors. Do you feel like taking the fan off and looking? Can you even take the fan off?
That's what was called for in my car, a 1970 Dart Swinger. So........what is 108 difference going to make? The cars always run hotter anyway. The lower temp gave you heat quicker, that's the only reason for it.