A worn-out or faulty thermostat on your 1997 Cadillac will cause the engine to overheat if it gets stuck in the closed position. The thermostat should open as the temperature in the engine rises beyond a predetermined point. This allows low temperature coolant from the radiator to flow freely into the engine block and cylinder head as hot coolant transfers into the radiator. Replacing the thermostat will fix this problem.
Air pockets in the coolant mixture will create hot spots around the engine block or cylinder head. Coolant carries the heat away from the engine and to the radiator, where fresh air traveling through the radiator dissipates the heat. However, air pockets will keep the heat in the engine. Checking the coolant level and bleeding the cooling system will get rid of the hot spots.
Loose hose clamps, damaged coolant hoses and cooling system components slowly leak system pressure, making it hard to detect. In most cases, you will notice a drop in coolant level. A close inspection of clamps, hoses and radiator body may reveal these small leaks. However, if the leak is coming through very small openings, taking your Cadillac to a service station for a cooling system and radiator-cap pressure test may uncover these pinhole leaks.
A fault in the cooling fan electrical circuit or motor may keep the fan from operating properly. A blown fuse, a broken relay, temperature sensor, fan motor or wire will keep the fan from operating properly, causing the engine to overheat. Checking the circuit and operating components can reveal the fault.
A blown head gasket or pores around the water jackets' casting in the cylinder head or block will cause a coolant leak. Engine age, poor maintenance and hard driving develop these types of problems in most cases.
Coolant needs to circulate from the radiator to the engine block and cylinder head of your 1997 Cadillac in order to transfer the heat away from the engine and provide low temperature coolant. However, when rust and scale builds up in the radiator, coolant does not transfer freely to the engine, if at all, causing overheating. In this case, take your vehicle to a service station to flush the cooling system. In severe cases, you must install a new or rebuilt radiator.
A faulty water pump will cause your Cadillac's engine to overheat. A worn seal will leak coolant; a faulty impeller, shaft or bearings will circulate coolant poorly or not at all. A worn-out water pump, an overly tight drive belt and lack of coolant system maintenance are the most common causes of pump failure. Replacing the water pump will fix this problem.
