[mpumas]

Another possibilty why it is running hot is a clogged radiator. Your heater is doing what your radiator should be doing if you do not have a broken head. Symptoms of a head problem is water in the oil, water in the exhaust, water loss. excessive pressure in the radiator etc. Working on the radiator is the cheapest place to start. Radiator cleaner/flush will clean out some of the clogged ones. On others, you might have to take the radiator out and test and clean it out outside the car.