My diesel overheats to about 220 when giving it gas after about ten minutes driving. The fan can be moved side to side and I can see movement down by the spacer on the fan clutch. Something is squeeking especially in the cold. Putting on the heat makes no difference in temp. The radiators temp is 90 the thermostat is 177 on one side and 194 on the other side check with a hand held temp gun with laser pointer. When I let up on the gas it drops about 5 degrees imediately. Is it the fan clutch?