The things you want checked are, your antifreeze,your radiator cap,pressure test the system for leaks, and have a complete Flush and Fill. Just having a radiator drained and filled isnt a good idea. The reason I say that is, all your replaceing is your antifreeze in your radiator. The Car is turned off during this procedure and your just mixing a small amount of new antifreeze with the rest of the gunk built up in the rest of the system. Maybe on a newer car with less than 12,000 miles you might, get by.
I remember reading a few articles regarding the New 100,000 Antifreeze. It sounds great but, they found it was not true. At least General Motors did. And after working on alot of their cars I found old contaminated antifreeze that was causeing premature wear on the internal and external parts. I just recently purchased a 2001 Blazer with only 84,000 miles and had to flush the cooling system 4 times to remove all the rust and gunk built up in the heater core. After that my heater now blows HOT!
To sum it all up, have your thermostat and antifreeze replaced. And do not forget to have them pressure test your cooling system for leaks and do a complete Flush and Fill on your car or truck.
