What you are describing sounds normal.
By turning on the heat, the blower acts as an additional fan on the coolant and should lower the temp.
The a/c when turned on will allow the second fan to run to help reduce the extra heat produced.
If it is a little hotter than normal it may be a radiator that is partially restricted or restriction elsewhere. A sticky thermostat may also cause a abnormal temp reading. I would try a coolant flush if it is due. Check the fins on the rad for restriction of air also.
Monday, August 2nd, 2010 AT 2:43 PM