Depending on your particular model, you might have to disconnect and remove one or more hoses attached to the radiator outlet pipe between the radiator and the engine to change the thermostat on your Chevrolet Cavalier. Whichever your model, make a note of the location of these hoses before removing, then follow these steps to replace the thermostat.
Park your car in a safe place and open the bonnet; remove the radiator cap. Place a drain pan under the radiator drain valve, then open the valve and drain the coolant. After draining the coolant, close the radiator drain valve.
Follow the lower radiator hose from the radiator towards the engine. On the 2.2L engine models, remove the two mounting bolts securing the radiator hose to the inlet manifold using a ratchet and socket; separate the hose and remove the thermostat. On 2.3L and 2.4L engine models, remove the upper cover-to-outlet pipe bolt through one of the exhaust manifold runner using a ratchet, ratchet extension and socket. Raise the front of the car using a floor jack and safely support it on 2 jack stands. Then remove the outlet pipe to oil pan bolt and the bottom cover to outlet pipe bolt. Separate the pipe and remove the thermostat. Make a note of the direction the thermostat spring is pointing so that you install the thermostat in the same exact position.
Using a soft wire brush, clean the mating surfaces of the outlet pipe or inlet manifold. Then install a new O-ring on the centre of the thermostat and set the thermostat in place.
Install the outlet radiator hose to the inlet manifold on the 2.2L engine and tighten the bolts to 89-inch lbs. (10 Nm). On 2.3L and 2.4L engine models, install the bottom cover-to-outlet pipe bolt and tighten to 10 foot lbs. (14 Nm); install the outlet pipe to-oil pan bolt and tighten to 19 foot lbs. (26 Nm) and install and tighten the upper cover-to-outlet pipe bolt to 40 foot lbs. (54 Nm); then lower the vehicle.
Refill the coolant system with 50 per cent water and 50 per cent antifreeze through the radiator neck and replace the radiator cap (see Warnings). Fill the coolant reservoir with the same mixture and bring the level between the Add and Full Hot marks.
The vehicle manufacturer recommends filling the cooling system with GM Goodwrench DEX-COOL (silicate free) coolant only to prevent premature engine and heater core wear and radiator corrosion.