- Check the coolant reservoir of an overheating Saturn. Do not open the radiator cap while the engine is hot; you could be seriously injured by scalding fluid. If your coolant is low, fill it to the add level; this should take care of the problem. If you find yourself refilling the radiator within a few weeks, you might have a problem with a leak.
- A coolant leak might happen from a broken hose, a leaky water pump, a cracked reservoir or broken seal. If you can physically see a pool of fluid under your car, the leak is probably from a hose, water pump or cracked reservoir. If you can't see fluid, the leak may be internal. The most likely source of an internal leak is a cracked head-gasket.
Thermostat and Hoses
- If you don't have a leak -- and your coolant level seems to be fine -- you may have a thermostat issue. A malfunctioning thermostat can cause the car to restrict the flow of coolant through the system. Other causes may be a faulty cooling fan or a lower coolant-hose collapse. The lower coolant-hose has a reinforced metal spring to help keep its shape when the system is pulling fluid through it. The hose may clamp down and restrict coolant flow if the spring fails due to corrosion or mechanical failure.