Welcome to the club. Be prepared to drop a little (or a lot) of cash to get started. Check to see if the battery has a date stamp on it. The life span of a battery is 5 years, plus or minus 5 years. When they go bad, they cause a bunch of electrical problems that have no apparent cause before they degrade to the point that they won't start the car.
The cooling system has a life span of 75,000 miles, plus or minus 25,000 miles. Do a search for "Mango" and click on the cooling system link in his signature for details. Since it's your son's car you can wait for the first sign of trouble, and then replace the entire cooling system. It all fails in a six month period, so you might as well do it all at one time.
Tonight, order a PA Soft 1.4 scanner. It will read the codes that are thrown by the many processors controlling your car. It also allows you to program certain functions, like daytime running lights and other personal preferences. It's invaluable. There's a thread devoted to it on this forum.