Engine Cooling problem
1990 Plymouth Acclaim 4 cyl Two Wheel Drive Automatic 107000 miles
I have a 1990 Plymouth Acclaim. I have had it looked at by several mechanics and no one can tell me what's wrong. For some unknown reason it runs hot. The strange part is that on days it's cold or I have to have my heat on is when it runs the hottest. As far as what has been fixed/replaced here is the list. Head was cracked and fixed. Rad is new, thermostat is new along with the water pump. The fan was also found to be working properly. Hoses have all been replaced and I was told that the cooling system was bleed. Also the heater core was checked and found to be working. I'm not losing any coolant. When I stop at a light you can watch the gauge move up and when I start to drive you can watch it drop. The gauge was check to make sure it was in proper working order. When the heater is on (the ac doesn't work) the gauge never goes lower then 3/4. Please help me figure out what is going on. I have been told by more then one person that everything in the cooling system has been changed and they are not sure what would make my can do this. Also all of the belts have been replaced along with the timing chain and timing was reset. Thank you so much in advance for any help you can offer me.