SECTION 1D
ENGINE COOLING
Caution : ENGINE COOLINGCAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.
SPECIFICATIONS
Cooling System Specification
Application | Description | Unit | Standard |
Cooling System | Cooling Type | - | Forced Water Cooling |
Coolant | Type | - | Dexcool/Silicate Based Coolant |
Capacity | L | 6.0 (4.2 : 1.2 SOHC) |
Thermostat | Type | - | Wax Pellet |
Temperature (Opened Initially) | °C (°F) | 87 °C (189 °F) |
Temperature (Completely Opened) | °C (°F) | 102 °C (216 °F) |
Temperature (Completely Closed) | °C (°F) | 82 °C (180 °F) |
Stroke (Completely Opened) | mm (in.) | 7 (0.28) : SOHC 7 ~ 10 (0.28 ~ 0.39) : DOHC |
Cooling Fan | Type | - | Electrical Single Fan |
Number of Blade | EA | 5 |
Diameter | mm (in.) | With A/C : 366 (14.4) Without A/C : 300 (11.8) |
ON Temperature at Low Speed | °C (°F) | 93 (199.4) |
OFF Temperature at Low Speed | °C (°F) | 90.75 (195.35) : 1.2 SOHC, 90 (194) |
ON Temperature at High Speed | °C (°F) | 96.75 (206.15) : 1.2 SOHC, 97 (206.6) |
OFF Temperature at High Speed | °C (°F) | 94.5 (202.1) : 1.2 SOHC, 94 (201.2) |
Surge Tank | Open Pressure of the Pressure Valve | kPa | 1.2 SOHC : 120, 1.4 DOHC : 120 ~ 150 |
Open Pressure of the Vacuum Valve | kPa | 10 kPa |
Water Pump | Type | - | Centrifugal |
Impeller Diameter | mm (in.) | 55 (2.17) |
Number of Impeller Blade | EA | 11 |
Radiator | Type | - | Cross Flow |
Core Width | mm | 480 (1.4 DOHC with A.C : 600) |
Core Height | mm | 415 |
Core Depth | mm | 16 |
Minimum Cooling Capacity | Kcal/h | 27,400 (1.4 DOHC with A.C : 39,000) |
Fastener Tightening Specifications
Application | N•m | Lb-Ft | Lb-In |
Water Pump Mounting Bolts | 10 | - | 89 |
Electric Cooling Fan Motor Nut | 3.2 | - | 28 |
Electric Cooling Fan Motor Retaining Screws | 4 | - | 35 |
Electric Cooling Fan Assembly Mounting Bolts | 4 | - | 35 |
Engine Coolant Temperature Sensor | 20 | 15 | - |
Negative Battery Terminal Retainer Bolt | 15 | 11 | - |
Surge Tank Attaching Bolt | 10 | - | 89 |
Thermostat Housing Mounting Bolts | 20 | 15 | - |
Upper Left Radiator Retaining Bolt | 10 | - | 89 |
Upper Right Radiator Retaining Bolt | 10 | - | 89 |
DIAGNOSIS
Thermostat Test
- Remove the thermostat from the vehicle. Refer to "Thermostat" in this section.
- Make sure the valve spring is tight when the thermostat is fully closed. If the spring is not tight, replace the thermostat.
- Suspend the thermostat and a thermometer in a pan of 50/50 mixture of ethylene glycol and water. Do not let the thermostat or the thermometer rest on the bottom of the pan because the uneven concentration of heat on the bottom could result in inaccurate temperature measurements.
- Heat the pan on a burner.
- Use the thermometer to measure the temperature of the heated solution.
- The thermostat should begin to open at 87°C (189°F) and it should be fully open at 102°C (216°F). If it does not open at these temperatures, replace the thermostat.
Cooling Systen Diagnosis
Engine Overheats
Checks | Action |
Check for a loss of the coolant. | Add the coolant. |
Check for a weak coolant solution. | Confirm that the coolant solution is a 50/50 mixture of ethylene glycol and water. |
Check the front of the radiator for any dirt, any leaves, or any insects. | Clean the front of the radiator. |
Check for leakage from the hoses, the water pump, the heater, the thermostat housing, the radiator, the core plugs, or the head gasket. | Replace any damaged components. |
Check for a faulty thermostat. | Replace a damaged thermostat. |
Check for retarded ignition timing. | Perform a code diagnosis using the engine control module (ECM) for a vehicle with a manual transaxle. Confirm the integrity of the timing belt. |
Check for an improperly operating electric cooling fan. | Replace the electric cooling fan. |
Check for radiator hoses that are plugged or rotted. | Replace any damaged radiator hoses. |
Check for a faulty water pump. | Replace a faulty water pump. |
Check for a faulty surge tank cap. | Replace a faulty surge tank cap. |
Check for a cylinder head or an engine block that is cracked or plugged. | Replace a faulty water pump.Repair the damaged cylinder head or the damaged engine block. |
Loss of Coolant
Checks | Action |
Check for a leak in the radiator. | Replace a damaged radiator. |
Check for a leak in the following locations:
| Replace the following parts:
|
Check for the following loose or damaged parts: - Radiator hoses.
- Heater hoses.
- Connections.
| Reseat the hoses. Replace the hoses or the clamps. |
Check for leaks in the water pump seal. | Replace the water pump seal. |
Check for leaks in the water pump gasket. | Replace the water pump gasket. |
Check for an improper cylinder head torque. | Tighten the cylinder head bolts to specifications. Replace the cylinder head gasket, if needed. |
Check for leaks in the following locations: - Intake manifold.
- Cylinder head gasket.
- Cylinder block plug.
- Heater core.
- Radiator drain plug.
| Repair or replace any components, as needed, to correct the leak. |
Engine Fails to Reach Normal Operating Temperature or Cool Air from the Heater
Checks | Action |
Check to determine if the thermostat is stuck open, or if it is the wrong type of thermostat. | Install a new thermostat of the correct type and heat range. |
Check the coolant level to determine if it is below the MIN mark on the surge tank. | Add sufficient coolant to raise the fluid to the specified mark on the surge tank. |
COMPONENT LOCATOR
Radiator/Fan
- Bolt
- Cooling Fan Assembly
- Radiator
- Upper Radiator Hose
- Spring Clamp
- Radiator Bumper
- Radiator Bracket
- Drain Cock
- Bolt
Water Pump/Thermostat (1.2 SOHC)
- Thermostat Housing Bolt
- Thermostat Housing
- Thermostat
- Water Pump Mounting Bolt
- Water Pump Mounting Nut
- Water Pump
- Water Pump Gasket
Water Pump/Thermostat (1.4 DOHC)
- Thermostat Housing Bolt
- Thermostat Housing Assembly
- Seal Ring
- Water Pump Mounting Bolts
- Water Pump
- O-Ring
MAINTENANCE AND REPAIR
ON-VEHICLE SERVICE
Draining and Refilling the Cooling System
Caution : To avoid injury, do not remove the surge tank cap while the engine and the radiator are hot. Scalding fluid and steam may be blown out under pressure.
- Place a pan below the vehicle to catch the draining coolant.
- Remove the surge tank cap.
- Unplug the drain cock.
Caution : Dispose of the used coolant in a used coolant holding tank to be picked up with the used oil for disposal. Never pour the used coolant down the drain. Ethylene glycol antifreeze is an extremely toxic chemical. Disposing of it into the sewer system or the ground water can contaminate the local environment.
- Catch the escaping fluid in a drain pan.
- Remove all sludge and dirt from inside the surge tank. Refer to "Surge Tank"in this section.
- Plug the drain cock.
- Add clean water to the surge tank.
- Fill the tank slowly so that the upper reservoir hose remains above the water line. This allows the air inside the cooling system to escape.
- Start the engine.
- Run the engine until the thermostat opens. You can tell the thermostat is open when both radiator hoses are hot to the touch.
- Stop the engine.
- Repeat Steps 1 through 9 until the drained water is clear and free of coolant and rust.
Notice : To avoid damaging the vehicle, never use an antifreeze mixture more concentrated than 60 percent antifreeze to 40 percent water. The solution freezing point increases above this concentration.
- Fill the cooling system through the surge tank with a mixture of ethylene glycol antifreeze and water. The mixture must be at least 50 percent antifreeze, but not more than 60 percent antifreeze for cold weather operation.
- Fill the surge tank to the specified MAX fill mark on the outside of the tank.
Thermostat (1.2 SOHC)
Removal Procedure
Caution : To Prevent personal injury, do not remove the surge tank cap while the engine and the radiator are hot because the heat causes the system to remain under pressure. Scalding fluid and steam may be blown out under pressure.
- Drain the coolant. Refer to "Draining and Refilling the Cooling System"in this section.
- Remove the thermostat housing retaining bolts (1).
- Remove the thermostat housing (2).
- Remove the thermostat (3).
- Inspect the thermostat for proper operation. Refer to “Thermostat Test” in this section.
- Clean the thermostat housing and the cylinder head mating surfaces.
Installation Procedure
- Install the thermostat into the cylinder head recess.
- Install the thermostat housing.
Tighten
Tighten the thermostat housing retaining bolts to 12 N•m (106 lb-in).
- Refill the engine cooling system. Refer to "Draining and Refilling the Cooling System"in this section.
Thermostat (1.4 DOHC)
Removal Procedure
Caution : To prevent personal injury, do not remove the surge tank cap while the engine and the radiator are hot because the heat causes the system to remain under pressure. Scalding fluid and steam may be blown out under pressure.
- Drain the coolant. Refer to "Draining and Refilling the Cooling System"in this section.
- Remove the engine beautification cover.
- Loosen the hose clamp on the upper radiator hose and the coolant hose-to-throttle body at the thermostat housing.
- Disconnect the upper radiator hose and the coolant hose-to-throttle body from the thermostat housing.
- Remove the mounting bolts that hold the thermostat housing to the cylinder head.
- Remove the thermostat housing from the cylinder head.
- Remove the thermostat from its recess in the cylinder head.
- Inspect the valve seat for foreign matter that could prevent the valve from sealing properly.
- Inspect the thermostat for proper operation. Refer to "Thermostat Test" in this section.
- Clean the thermostat housing and the cylinder head mating surfaces.
Installation Procedure
- Install the thermostat into the cylinder head recess.
- Install the thermostat housing.
- Secure the thermostat housing to the cylinder head with the mounting bolts.
Tighten
Tighten the thermostat housing mounting bolts to 20 N•m (15 lb-ft).
- Connect the upper radiator hose and the coolant hose-to-throttle body to the thermostat housing.
- Secure the upper radiator hose to the thermostat housing with a hose clamp.
- Install the engine beautification cover.
- Refill the engine cooling system. Refer to "Draining and Refilling the Cooling System"in this section.
Water Pump (1.2 SOHC)
Removal Procedure
- Drain the coolant. Refer to "Draining and Refilling the Cooling System" in this section.
- Remove the timing belt. Refer to Section 1B1, SOHC Engine Mechanical.
- Remove the lower timing belt cover.
- Remove the water pump retaining nuts (1), bolts (2).
- Remove the water pump (3).
- Remove the ring seal from the water pump.
- Inspect the water pump for cracks, leaks or abnormal noise.
- Cleaning the mating surfaces of the water pump and the cylinder head.
Installation Procedure
- Install a new ring seal to the water pump.
- Install the water pump to the engine block.
Tighten
Tighten the water pump retaining bolts and nuts to 10 N•m (89 lb-in).
- Install the lower timing belt cover.
Tighten
Tighten the lower timing belt cover retaining bolts to 10 N•m (89 lb-in).
- Refill the engine cooling system. Refer to "Draining and Refilling the Cooling System" in this section.
Water Pump (1.4 DOHC)
Removal Procedure
- Drain the engine cooling system to a level below the thermostat housing. Refer to "Draining and Refilling theCooling System"in this section.
- Remove the timing belt rear hood. Refer to Section 1B2, SOHC Engine Mechanical,
- Remove the water pump mounting bolts.
- Remove the water pump from the cylinder block.
- Remove the ring seal from the water pump.
Inspection Cleaning Procedure
- Inspect the water pump body for cracks and leaks.
- Inspect the water pump bearing for play or abnormal noise.
- Inspect the water pump pulley for excessive wear. If the water pump is defective, replace the water pump as a unit.
- Clean the mating surfaces of the water pump and cylinder block.
Installation Procedure
- Install a new ring seal to the water pump.
- Coat the sealing surface of the ring seal with Lubriplate®.
- Install the water pump to the engine block.
- Secure the water pump to the engine block with the mounting bolts.
Tighten
Tighten the water pump mounting bolts to 10 N•m (89 lb-in).
- Install the rear timing belt rear hood. Refer to Section 1B2, SOHC Engine Mechanical.
- Refill the engine cooling system. Refer to "Draining and Refilling the Cooling System" in this section.
Electric Cooling Fan
Removal Procedure
- Disconnect the negative battery cable.
- Disconnect the cooling fan electrical connector.
- Remove the electric cooling Fan Mounting bolts.
- Remove the electric cooling Fan.
Installation Procedure
Caution : If a fan blade is bent or damaged in any way, no attempt should be made to repair or reuse the damaged part. A bent or damaged fan assembly must be replaced with a new fan assembly. It is essential that fan assemblies remain in proper balance. A fan assembly that is not in proper balance can fail and fly apart during use, creating extreme danger. Proper balance cannot be assured on a fan assembly that has been bent or damaged.
- Install the electric cooling fan.
- Install the electric cooling Fan Mounting bolts.
Tighten
Tighten the electrical cooling fan moumting bolts to 4 N•m (35 lb-in).
- Connect the cooling fan electriceal connector
Surge Tank
Removal Procedure
Caution : To prevent personal injury, do not remove the surge tank cap while the engine and the radiator are hot, because the heat causes the system to remain under pressure. Scalding fluid and steam may be blown out under pressure.
- Drain the engine coolant to below the level of the surge tank.
- Loosen the overflow hose clamps and disconnect the overflow hose from the top of the surge tank.
- Remove the tank attaching nuts.
- Remove the tank from the vehicle.
- Clean the inside and the outside of the surge tank and the surge tank cap with soap and water.
- Rinse the surge tank and the cap thoroughly.
Installation Procedure
- Install the surge tank to the vehicle.
- Secure the surge tank with the attaching nuts.
Tighten
Tighten the surge tank attaching nuts to 10 N•m (89 lb-in).
- Connect the overflow hose to the surge tank.
- Secure the overflow hose to the surge tank with the hose clamps.
- Fill the surge tank with the coolant to the center ridge, or to the MAX mark.
Radiator
Removal Procedure
- Disconnect the negative battery cable.
- Drain the engine cooling system. Refer to "Draining and Refilling the Cooling System" in this section.
- Remove the electric cooling fans. Refer to "Electric Cooling Fan"in this section.
- Remove the upper radiator hose clamp.
- Disconnect the upper radiator hose from the radiator.
- Remove the lower radiator hose clamp.
- Disconnect the lower radiator hose from the radiator.
- For the vehicle equipped with the auto transaxle, disconnect the oil cooling pipe from the radiator. Refer to Section 5A, AISIN Automatic Transaxle.
- Remove the hose clamp from the surge tank hose at the radiator.
- Disconnect the surge tank hose from the radiator.
- Remove the left upper radiator retaining bolt.
- Remove the left upper radiator retaining bracket.
- Remove the right upper radiator retaining bolt.
- Remove the right upper radiator retaining bracket.
- Remove the radiator from the vehicle.
Important : The radiator still contains a substantial amount of coolant. Drain the remainder of the coolant from the radiator into a drain pan.
Installation Procedure
- Set the radiator into place in the vehicle with the rediator bottom posts in the rubber shock bumpers.
- Position the radiator retainers in place.
- Install the upper right radiator retaining bracket.
- Install the upper right radiator retaining bolt.
Tighten
Tighten the upper right radiator retaining bolt to 10 N•m (89 lb-in).
- Install the upper left radiator retaining bracket.
- Install the upper left radiator retaining bolt.
Tighten
Tighten the upper lef radiator retaining bolt to 10 N•m (89 lb-in).
- Connect the surge tank hose to the radiator.
- Secure the surge tank hose with a hose clamp.
- Connect the upper radiator hose and the lower radiator hose to the radiator.
- Secure each hose with a hose clamp.
- Connect the automatic transaxle oil cooling pipe to the radiator. Refer to Section 5A, AISIN Automatic Transaxle.
- Install the electric cooling fans. Refer to "Electric Cooling Fan"in this section.
- Refill the engine cooling system. Refer to "Draining and Refilling the Cooling System"in this section.
- Connect the negative battery cable.
GENERAL DESCRIPTIONAND SYSTEM OPERATION
General Description
The cooling system maintains the engine temperature at an efficient level during all engine operating conditions. When the engine is cold, the cooling system cools the engine slowly or not at all. This slow cooling of the engine allows the engine to warm up quickly.
The cooling system includes a radiator and recovery subsystem, cooling fans, a thermostat and housing, a water pump, and a water pump drive belt. The timing belt drives the water pump.
All components must function properly in order for the cooling system to operate. The water pump draws the coolant from the radiator. The coolant then circulates through water jackets in the engine block, the intake manifold, and the cylinder head. When the coolant reaches the operating temperature of the thermostat, the thermostat opens. The coolant then goes back to the radiator where it cools.
This system directs some coolant through the hoses to the heater core. This provides for heating and defrosting. The surge tank is connected to the radiator to recover the coolant displaced by expansion from the high temperatures. The surge tank maintains the correct coolant level
The cooling system for this vehicle has no radiator cap or filler neck. The coolant is added to the cooling system through the surge tank.
Radiator
This vehicle has a lightweight tube-and-fin aluminum radiator. Two models of radiators are available: small, standard, and heavy duty. The two models vary only by capacity. Plastic tanks are mounted on the right and the left sides of the radiator core.
On vehicles equipped with automatic transaxles, the transaxle fluid cooler lines run through the left radiator tank. A radiator drain cock is on this radiator.
To drain the cooling system, open the drain cock.
Surge Tank
The surge tank is a transparent plastic reservoir, similar to the windshield washer reservoir.
The surge tank is connected to the radiator by a hose and to the engine cooling system by another hose. As the vehicle is driven, the engine coolant heats and expands. The portion of the engine coolant displaced by this expansion flows from the radiator and the engine into the surge tank. The air trapped in the radiator and the engine is degassed into the surge tank.
When the engine stops, the engine coolant cools and contracts. The displaced engine coolant is then drawn back into the radiator and the engine. This keeps the radiator filled with coolant to the desired level at all times and increases the cooling efficiency.
Maintain the coolant level between the MIN and the MAX marks on the surge tank when the system is cold.
Water Pump
The belt-driven centrifugal water pump consists of an impeller, a drive shaft, and a belt pulley. The water pump is mounted on the front of the transverse-mounted engine, and is driven by the timing belt.
The impeller is supported by a completely sealed bearing.
The water pump is serviced as an assembly and, therefore, cannot be disassembled.
Thermostat
A wax pellet-type thermostat controls the flow of the engine coolant through the engine cooling system. The thermostat is mounted in the thermostat housing to the front of the cylinder head.
The thermostat stops the flow of the engine coolant from the engine to the radiator to provide faster warm-up, and to regulate the coolant temperature. The thermostat remains closed while the engine coolant is cold, preventing circulation of the engine coolant through the radiator. At this point, the engine coolant is allowed to circulate only throughout the heater core to warm it quickly and evenly.
As the engine warms, the thermostat opens. This allows the engine coolant to flow through the radiator where the heat is dissipated through the radiator. This opening and closing of the thermostat permits enough engine coolant to enter the radiator to keep the engine within proper engine temperature operating limits.
The wax pellet in the thermostat is hermetically sealed in a metal case. The wax wax element of the thermostat expands when it is heated and contracts when it is cooled.
As the vehicle is driven and the engine warms, the engine coolant temperature increases. When the engine coolant reaches a specified temperature, the wax pellet element in the thermostat expands and exerts pressure against the metal case, forcing the valve open. This allows the engine coolant to flow through the engine cooling system and cool the engine.
As the wax pellet cools, the contraction allows a spring to close the valve.
The thermostat begins to open at 87°C (189°F) and is fully open at 102°C (216 °F). The thermostat closes at 86°C (187°F).
Electric Cooling Fan
Caution : Keep hands, tools, and clothing away from the engine cooling fans to help prevent personal injury. This fan is electric and can turn ON whether or not the engine is running.
Caution : If a fan blade is bent or damaged in any way, no attempt should be made to repair or reuse the damaged part. A bent or damaged fan assembly should always be replaced with a new one.
The cooling fans are mounted behind the radiator in the engine compartment. The electric cooling fans increase the flow of air across the radiator fins and across the condenser on air conditioned (A/C)-equipped vehicles. This helps to speed cooling when the vehicle is at idle ormoving at low speeds.
The fan size is 366 mm (14.4 inches) (Non-A/C model is 300mm (11.8inches))in diameter with five blades to aid the airflow through the radiator and the condenser. An electric motor attached to the radiator support drives the fan.
A/C Off or Non-A/C Model
- The cooling fan(s) are actuated by the powertrain control module (PCM) in vehicles with an automatic transaxle or the engine control module (ECM) using a low-speed cooling fan relay and a high-speed cooling fan relay. On A/C-equipped vehicles, a series/parallel cooling fan relay is also used.
- The PCM or the ECM will turn the cooling fan(s) on at low speed when the coolant temperature reaches 93°C (199°F) and high speed at 97°C (207°F).
- The PCM or the ECM will change the cooling fan(s) from high speed to low speed at 94°C (201°F) and turn the cooling fans off at 90°C (194°F).
A/C ON
- The PCM or the ECM will turn the cooling fans on at low speed when the A/C system is on. The PCM or the ECM will change to high speed when the coolant temperature reaches 97°C (207°F) or high-side A/C pressure reaches 1 882 kPa (273 psi).
- The cooling fans will return to low speed when the coolant temperature reaches 94°C (201°F) or high-side A/C pressure reaches 1 448 kPa (210 psi).
Engine Coolant Temperature Sensor
The coolant temperature sensor (CTS) uses a thermistor to control the signal voltage to the engine control module (ECM) and controls the instrument panel temperature indicator.
Engine Block Heater
The vehicle is designed to accept an engine block heater. The engine block heater helps to warm the engine for improved cold weather starting. It can also help reduce fuel consumption when a cold engine is warming up.
The engine block heater utilizes an existing expansion plug for installation and is located under the intake manifold.
Contact your Daewoo dealer for further information or installation.
