Changing the Thermostat in an '01 S10

From its debut in 1982 through its final year in 2004, the S10 was a key component in keeping truck buyers of all sorts interested in Chevy trucks. The 2001 S10 came standard with a 2.2-liter four-cylinder engine that cranked out 120 horsepower. A small temperature-controlled valve, called the thermostat, regulated the 2.2-liter engines temperature so it remained in an acceptable range. When the thermostat fails, two drastically different symptoms may occur: overheating or over-cooling. Changing the thermostat on the 2001 S10 requires partially draining the cooling system, but overall, it is a straightforward task.

Instructions

1

Unscrew the pressure cap from the top of the radiator and the coolant recovery tank.

2

Raise the front of the S10 with a floor jack and set jack stands under the vehicles frame rails. Lower the truck onto the jack stands.

3

Crawl beneath the truck until you are directly under the petcock the radiator drain screw on the bottom, drivers side of the radiator. Set a drain pan under the radiator petcock and turn the petcock counterclockwise to start draining coolant from the radiator.

4

Allow about 2 to 3 inches of coolant to drain into the drain pan, then turn the petcock clockwise to close it.

5

Raise the truck off the jack stands with a floor jack and remove the jack stands. Lower the S10 to the ground.

6

Trace the upper radiator hose from the top until you find where it connects to the thermostat housing, the metal connector between the radiator hose and the engine. Slide the hose clamp on the end of the upper radiator hose about 3 inches toward the center of the hose, using slip-joint pliers. Pull the upper radiator hose from the thermostat housing, using a slight twisting motion.

7

Remove the two bolts from the thermostat housing, using a ratchet and socket, and pull the housing from the engine, exposing the thermostat. Pull the thermostat from the engine.

8

Pry the rubber O-ring from the groove in the engine block, using a flat-head screwdriver. Clean the mating surface on the engine block and the thermostat housing, using a plastic gasket scraper and a clean, lint-free cloth.

9

Coat the new O-ring with 50-50 premixed Dex-Cool coolant and press it into its groove in the engine block.

10

Guide a new thermostat into the engine, spring side first, into the engine block and set the thermostat housing in place over the thermostat, aligning its bolt holes with those in the engine block. Hand-thread the thermostat housing bolts, then torque them to 89 inch-pounds, using an inch-pound torque wrench and socket.

11

Press the upper radiator hose back onto the thermostat housing and slide the hose clamp to within 1 inch of the thermostat housing end of the radiator hose, using slip-joint pliers.

12

Pour 50-50 premixed Dex-Cool coolant into the radiator until the coolant level reaches the base of the filler neck. Add 50-50 premixed Dex-Cool coolant to the coolant recovery tank until the coolant level reaches the Add mark on the tank. Tighten the cap onto the coolant recovery tank, but not onto the radiator.

13

Start the engine and let it idle until the upper radiator hose feels hot. Check the level in the radiator and add more coolant until the level reaches the base of the filler neck, if needed. Tighten the radiator cap and turn off the engine.

14

Take old coolant to a nearby used-automotive fluid recycling center for disposal. Some auto parts stores take old coolant free of charge.