How to Replace a Thermostat on a 1993 Chevrolet Lumina

The thermostat in your 1993 Chevrolet Lumina helps determine how much coolant is circulated within the engine, keeping it within a proper temperature range. A failed thermostat will either stick open, which allows too much coolant into the engine and causes the engine to warm up much later than expected, or stick closed, preventing coolant from reaching the engine and causing it to overheat. Replacing this part when it fails is important for maintaining the health of your engine.

Instructions

1

Open the hood and disconnect the negative battery cable. This will prevent the possibility of shock while working on the vehicle.

2

Allow the engine to cool down before attempting any repairs. Locate the thermostat by tracing the large upper radiator hose from the upper portion of the radiator back to the engine. The point where the hose stops will be where the thermostat housing is located.

3

Locate the drain plug at the bottom of the radiator and place a drain pan underneath. Remove the drain plug with a ratchet and socket and allow the coolant to drain out of the radiator.

4

Loosen the retaining clamp with a slotted screwdriver. Move the clamp out of the way and pull the hose off of the thermostat housing. Remove the two bolts holding the thermostat housing with a ratchet and socket.

5

Pry the thermostat housing off with a slotted screwdriver. Make a note of how the thermostat is positioned within the recess, as the new part has to be installed the same way. Remove both the thermostat and the O-ring. Clean all remaining debris from the mounting surface.

6

Install the new O-ring on the mounting surface and place the thermostat inside the recess. Place the housing over the thermostat and tighten the two retaining bolts with a ratchet and socket. Slip the upper radiator hose over the thermostat housing inlet and reattach the retaining clip. Tighten the clip with a slotted screwdriver.

7

Replace the drain plug on the radiator. Move the drain pan out of the way and refill the radiator with fresh coolant. Check the areas underneath and around the radiator and thermostat housing for leaks.

8

Reconnect the negative battery cable and start the vehicle. Monitor the coolant levels and add fresh coolant as needed. Dispose of the old coolant in a safe and environmentally friendly manner.