This is the time of year when we start to see overheating problems, unless you live where I do as we have had an unusually cool summer, There are several things that can cause overheating, thermostat, low coolant, inoperative cooling fan all of these are easy to check if you don’t have a noncontact thermometer I would suggest purchasing one Sears has one for a little over $40 on sale. You will be surprised at the uses you will find for it. One overlooked problem that can cause overheating is a blocked space between the radiator and condenser. Easy to clean at the local car wash or at home with a garden hose. Also check for blocked passages in the radiator a simple check with a flashlight if they are blocked the radiator will have to be removed and professionally repaired. I recommend flushing every other year. To flush simply locate the input heater hose and attach a hose let the water run, until it comes out of the top of the radiator clear. If the coolant is severely dirty you may want to add a chemical flushing additive.There are also some odd problems that can cause overheating, a lose water pump impeller, an obstruction in the system IE a collapsed hose, air in the system. Do not run the old coolant into the storm drain as it will pollute some places this is also illegal.