Engine Cooling System: Overview Dodge Challenger III

DESCRIPTION

The accessory drive belt is a serpentine type belt. Satisfactory performance of these belts depends on belt condition and proper belt tension.

Scheme 6

When diagnosing serpentine accessory drive belts, small cracks (1) that run across the ribbed surface of the belt from rib to rib , are considered normal. These are not a reason to replace the belt. However, cracks (2) running along a rib (not across) are not normal. Any belt with cracks running along a rib must be replaced. Also replace the belt if it has excessive wear, frayed cords, severe glazing or chunking.

Any belt with bumps, surface coming apart, or any other uneven indications along the flat surface of the belt must be remove and inspected and replaced if necessary.

Refer to ACCESSORY DRIVE BELT DIAGNOSIS CHART for further belt diagnosis.

OPERATION

The automatic belt tensioner maintains belt tension by using internal spring pressure, a pivoting arm and pulley to apply force against the drive belt.

Scheme 7

1. Remove accessory drive belt. See «Cooling/Accessory Drive/BELT, Serpentine - Removal»(ref-353989-S00873162722010011300000) .
2. Remove tensioner assembly bolt (2).
3. Remove accessory drive belt tensioner (1) from front engine cover (3).

Scheme 8

1. Remove the accessory drive belt. See «Cooling/Accessory Drive/BELT, Serpentine - Removal»(ref-353989-S00873162722010011300000) .
2. Remove the tensioner and the mounting bracket.
3. Remove the tensioner assembly from the mounting bracket.

Scheme 9

1. Remove accessory drive belt. See «Cooling/Accessory Drive/BELT, Serpentine - Removal»(ref-353989-S00873162722010011300000) . WARNING: Because of high spring pressure, do not attempt to disassemble automatic tensioner. Unit is serviced as an assembly.
2. Remove tensioner assembly bolt (2).
3. Remove tensioner assembly (1) from mounting bracket.

Scheme 10

1. Install tensioner bolt (2) to tensioner (1). Tighten bolt to 34 N.m (40 ft. lbs.).
2. Install accessory drive belt. See «Cooling/Accessory Drive/BELT, Serpentine - Installation»(ref-353989-S17064831522010011300000) .
3. Check belt indexing marks.

A vent valve in the center of the cap will remain shut as long as the cooling system is pressurized. As the coolant cools, it contracts and creates a vacuum in cooling system. This causes the vacuum valve to open and coolant in reserve/overflow tank to be drawn through connecting hose into radiator. If the vacuum valve is stuck shut, or overflow hose is kinked, radiator hoses will collapse on cool-down.

Coolant flows through the engine block absorbing the heat from the engine, then flows to the radiator where the cooling fins in the radiator transfers the heat from the coolant to the atmosphere. During cold weather the ethylene-glycol or propylene-glycol coolant prevents water present in the cooling system from freezing within temperatures indicated by mixture ratio of coolant to water.

When power is applied (110 volt AC) to the block heater, the heating element transfers heat through the aluminum engine block and into the coolant without directly penetrating the cooling system.

The engine cooling thermostats are a wax pellet driven, reverse poppet choke type. The thermostats have an air bleed located in the thermostat flange. The air bleed allows internal trapped air during cooling system filling to be released. The thermostat on the 2.7L and 3.5L engines are located on the lower left side of engine, near the front. The thermostat on both engines are on the inlet side of the water pump.

The thermostat on the 5.7L/6.1L engine is located beneath the thermostat housing (1) at the front of the intake manifold.

Scheme 11

The thermostat on the 3.0L Diesel engine is integrated into the thermostat housing located at the front of the right intake manifold and is serviced as an assembly. A rubber seal is used to seal the thermostat housing to the intake manifold. The thermostat contains the following components

1. Main Valve (4) - Controls coolant flow through the radiator
2. Bypass Valve (2) - Controls coolant flow through the bypass passage to the inlet side of the water pump
3. Vent Valve (1) - Vents the cooling system via a ball valve when it is filled and when the engine is running
4. Thermostat Housing Seal (3)

Scheme 12

Up to a coolant temperature of approximately 87° C (189° F), the main valve is closed and the bypass valve fully open. The flow through the radiator is interrupted and coolant flows through the bypass passage directly to the inlet side of the water pump.

Scheme 13

The main valve begins to open at a coolant temperature of 86° C (189° F), and a small amount of coolant flows through the radiator. As the engine temperature increases, the main valve opens further and the bypass valve gradually closes. More coolant flows through the radiator and less coolant flows through the bypass passage.

Scheme 14

The main valve is fully open at a coolant temperature above 102° C (216° F). The bypass plate seals off the bypass passage. The entire quantity of coolant flows through the radiator.

TRANSMISSION OIL COOLER REVERSE FLUSHING DESCRIPTION

Reverse flushing of the transmission oil cooling system is the forcing of fluid (ATF+4) in the opposite direction of normal fluid flow through the cooling system. It is necessary to perform this procedure anytime the transmission is serviced to avoid possible contamination of the cooling system. DO NOT PERFORM THIS PROCEDURE ON ANY VEHICLE THAT DOES NOT USE MOPAR® ATF+4 TRANSMISSION FLUID.

Scheme 15

Note. Refer to the Transmission Cooler Cleaner's operating instructions before starting this procedure.

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Scheme 17

1. Remove the transmission from the vehicle. Refer to the specific vehicle's transmission removal procedure.
2. Using tool 9038-1, trans cooler cleaner adapter kit (TCCAK) (1), select the proper adapter/fitting for the vehicle you are performing the procedure on.
3. Install the selected adapter/fitting to the transmission oil cooler inlet (2) and outlet (1) lines.
4. Connect the red hose (outlet) of the 9038 trans cooler cleaner (TCC) to the transmission oil cooler outlet line (1).
5. Connect the blue hose (inlet) of the 9038 trans cooler cleaner (TCC) to the transmission oil cooler inlet line (2).
6. Before starting the 9038 trans cooler cleaner (TCC), check the filter screen (2) for any debris. If debris is present, clean the filter screen in a parts washer and dry completely. CAUTION: FILTER SCREEN (2) MUST BE COMPLETELY CLEAN AND DRY BEFORE PROCEEDING. FAILURE TO COMPLY COULD RESULT IN POSSIBLE CONTAMINATION AND DAMAGE TO THE COOLING SYSTEM.
7. Connect a compressed air line (90 to 120 psi recommended) to the air inlet fitting located on the rear of the 9038 trans cooler cleaner (TCC).
8. Power up and pre-heat the 9038 trans cooler cleaner (TCC) machine to 190°F (will take approximately 45 minutes with a full tank of fluid).
9. Refer to the 9038 transmission cooler cleaner's (TCC) owners manual and quick reference card for detailed operating instructions. NOTE: It is recommended to flush/clean the system in 30 minute intervals.

The air-to-oil transmission cooler system has a thermal bypass valve assembly that controls fluid flow through the cooler. When the transmission fluid is cold (less then operating temperature), the fluid is routed through the cooler bypass valve without flowing through the transmission cooler. When the transmission fluid reaches operating temperatures 71°C (160°F) and above, the thermostat closes off the bypass and allowing fluid to flow through the transmission cooler. The thermal bypass valve is serviced as an assembly.