Nuts and Bolts with Buffalo Jim

Hey Buffalo,

It's not even summer yet, and the thermometer in my Saturn is already inching up toward the red line. What can I do to keep it from overheating as the heat climbs into the triple digits?

Hey, bro, summer isn't easy on me either with this big burly beard and all, but I find ways to keep cool. The first key is to drinking plenty of fluids, which is coolant to your car. So, take off your radiator cap and make sure the radiator's topped off. If you don't see the green stuff, fill it up with a 50/50 mix and put the cap back until it's snugged all the way up. While you're at it, check to make sure there's at least a little coolant in your overflow tank. Don't overfill that, though, unless you want a little green lake in your driveway.

Now, if you give your car a cold drink and it still overheats, the next thing to do is pressure test your radiator cap. It requires a pump and an adaptor, but most shops will do it for free, as long as they're cool (and they want to keep you cool). A good cap will hold about 15 pounds of pressure, which should be plenty to get you through the desert and back again.

If the cap's good, the other two possibilities are a bad fan or a plugged radiator/thermostat. You'll know it's the fan if the car overheats at idle because a car doesn't need a fan when it's cruising at 65 mph. On the other hand, if you're driving on the highway and the car overheats, that's a flow problem, which usually means either a partially plugged radiator or a stuck thermostat. If that's the case, you're either going to have to swap out the thermostat or have the radiator flow-tested to see if that's what's putting you and your car in the red.

Buffalo Jim is the owner of Allstate Auto Marine. E-mail your automotive questions and conundrums to him at buffalojim@lasvegasmercury.com. If you're nice, he might even tell you how Kid Rock blew up his car.