Thermostat Explanation

THERMOSTAT DESCRIPTION, 3.6L
CAUTION: Do not operate an engine without a thermostat, except for servicing or testing.

A pellet-type thermostat controls the operating temperature of the engine by controlling the amount of coolant flow to the radiator. On all engines the thermostat is closed below 195°F (90°C). Above this temperature, coolant is allowed to flow to the radiator. This provides quick engine warm up and overall temperature control.

The same thermostat is used for winter and summer seasons. An engine should not be operated without a thermostat, except for servicing or testing. Operating without a thermostat causes other problems. These are: longer engine warm-up time, unreliable warm-up performance, increased exhaust emissions and crankcase condensation. This condensation can result in sludge formation.

THERMOSTAT OPERATION
The wax pellet is located in a sealed container at the spring end of the thermostat. When heated, the pellet expands, overcoming closing spring tension and water pump pressure to force the valve to open.

THERMOSTAT REMOVAL, 3.6L
WARNING: Do not loosen radiator draincock with system hot and pressurized. Serious burns from coolant can occur.
CAUTION: The Thermostat and housing is serviced as an assembly. Do not remove the thermostat from the housing, damage to the thermostat may occur.
1. Disconnect and isolate the negative battery cable.
2. Remove the engine cover.
3. Remove the air cleaner body. Refer to BODY, AIR CLEANER, REMOVAL.
4. Drain the cooling system. Refer to STANDARD PROCEDURE.
5. Remove the upper radiator hose from the thermostat housing (Fig. 1) #1.
6. Remove bolts and thermostat housing (Fig. 1) #1 with thermostat #3.
7. Remove and discard the thermostat housing gasket.

THERMOSTAT COOLANT CROSSOVER REMOVAL, 3.6L
1. Remove the thermostat housing assembly (1). Refer to THERMOSTAT, REMOVAL.
2. Remove the accessory drive belt (Fig. 2) #7. Refer to BELT, SERPENTINE, REMOVAL.
3. Remove the Heater supply hose from the coolant crossover (Fig. 3) #1.
4. Remove the coolant crossover mounting bolts. Take notice to the four bolts (Fig. 3) #2 that bolt directly to the timing cover.
5. Remove the coolant crossover and discard Gaskets.

THERMOSTAT INSTALLATION, 3.6L
CAUTION: The Thermostat and housing is serviced as an assembly. Do not remove the thermostat from the housing, damage to the thermostat may occur.
1. Clean mating areas of timing chain cover and thermostat housing (Fig. 1) #1.
2. Install a new gasket on to the thermostat housing.
3. Install the thermostat housing (1). Tighten bolts to the proper SPECIFICATIONS.
4. Install the upper radiator hose to the thermostat housing (Fig. 1) #1.
5. Fill the cooling system. Refer to STANDARD PROCEDURE.
6. Install the air cleaner body. Refer to BODY, AIR CLEANER, INSTALLATION.
 7. Install the engine cover.
8. Connect the negative battery cable.
9. Start and check for leaks.

THERMOSTAT COOLANT CROSSOVER INSTALLATION, 3.6L
1. Clean gasket sealing surfaces.
2. Install new gasket onto the coolant crossover.
NOTE: The shorter M6 mounting bolts (Fig. 3) #2, bolt directly to the engine timing cover.
3. Hand tighten M6 mounting bolts. Tighten the bolts in a criss-cross pattern to 12 N.m (106 in. lbs.).
4. Install the heater supply hose to the coolant crossover (Fig. 3) #1.
5. Install the accessory drive belt. Refer to BELT, SERPENTINE, INSTALLATION.
6. Install the thermostat housing. Refer to THERMOSTAT, INSTALLATION .