Hyundai Elantra AD: Cooling System

Sixth generation (AD; 2017–2020) / Hyundai Elantra AD 2017-2020 Service Manual / Engine Mechanical System / Cooling System

Coolant Repair procedures

Refilling And Bleeding

•	Never remove the radiator cap when the engine is hot. Serious scalding could be caused by hot fluid under high pressure escaping from the radiator

•	When pouring engine coolant, be sure to shut the relay box lid and not to let coolant spill on the electrical parts or the paint. If any coolant spills, rinse it off immediately.

1.	Make sure the engine and radiator are cool to the touch.

2.	Remove the radiator cap (A).

3.	Remove the engine room under cover. (Refer to Engine And Transaxle Assembly - “Engine Room Under Cover”)

4.	Loosen the drain plug (A) and drain the coolant.

5.	Tighten the radiator drain plug securely.

6.	After draining engine coolant in the reservoir tank, clean the tank.

Fill fluid mixture with coolant and water (55~60%) (except for North America, Europe and China: 45~50%) slowly through the radiator cap.

•	Use only genuine antifreeze/coolant.

•

For best corrosion protection, the coolant concentration must be maintained year-round at 55% (except for North America, Europe and China: 45%) minimum.

Coolant concentrations less than 55% (except for North America, Europe and China: 45%) may not provide sufficient protection against corrosion or freezing.

•	Coolant concentrations greater then 60% will impair cooling efficiency and are not recommended.

•	Always use new coolant.

•	Do not mix different brands of antifreeze/coolants.

•	Do not use additional rust inhibitors or antirust products; they may not be compatible with the coolant.

Perform the engine coolant filling mode on GDS to bleed air out of the cooling system.

•	As an electric thermostat (opening temperature 100°C) is applied in the engine, fill up the coolant and use the GDS to enter the coolant filling mode and let out the air.

[Engine Coolant Filling Mode]

•	Guide Text on GDS: In an engine equipped with an electric thermostat (ECT), the current is applied to the electric thermostat while filling the coolant to help let out the air sufficiently.

1. Turn the ignition switch OFF.

2. Connect the GDS to Data Link Connector (DLC).

3. Turn the igntion switch ON.

4. Select "Vehicle, Model Year, Engine, System".

5. Select "Vehicle S/W Management".

? Conditions for Entering the Filling Mode

1. The shift lever is at the P position and the parkingbrake is applied.

2. The engine is idle.

3. The coolant temperature is 75°C or above.

4. The vehicle speed is 0 km/h.

5. The heater is turned off.

6. Perform the work indoors to help raise the coolant temperature.

[Check the coolant temperature]

? Conditions for Deactivating the Filling Mode

1. The coolant temperature is 90°C (194°F) or above.

2. The filling mode stop option is selected in the diagnostic device.

3. The conditions for entering the filling mode are not satisfied.

4. A filling mode abort condition occurs such as an ECT heater failure or a WTS failure.

•	Don’t accelerate the engine.

9.	Install the radiator cap and fill the reservoir tank to the "MAX“+0.4L (or "FULL“+0.4L) line with coolant.

10.	Stop the engine and wait coolant gets cool.

11.

Repeat 8 to 10 until the coolant level doesn't fall any more, bleed air out of the cooling system.

•	It takes time to bleed out all the air in the cooling system. Refill coolant when coolant gets cool completely, then recheck the coolant level in the reservoir tank for 2~3 days after replacing coolant.

Coolant capacity

Approx. 6.6 L (1.66 U.S.gal., 6.97 U.S.qt., 5.81 lmp.qt.)

Cooling Fan Components and Components Location

Components

1. Cooling fan
2. Fan motor

3. Cooling fan shroud
4. Cooling fan resistor

Cooling Fan Specifications

Specifications

Item	Specification
Fan type	Puller
Fan speed control	Resistor (HI-LOW-OFF)
Air flow rate [m?/h (yd?/h)]	1,950 -8% min.
Fan speed (rpm)	1,650 ± 8%
Current (A)	11.7 + 10% max.

Cooling Fan Schematic Diagrams

Circuit Diagram

Cooling Fan Repair procedures

Removal and Installation

Cooling fan assembly

1.	Disconnect the battery negative terminal.

2.	Remove the air duct and air cleaner assembly. (Refer to Intake and Exhaust System - "Air Cleaner")

3.	Disconnect the over flow hose (A).

Remove the filler neck assembly (A).

Tightening torque :

3.9 ~ 5.9 N.m (0.4 ~ 0.6 kgf.m, 2.9 ~ 4.3 Ib-ft)

5.	Disconnect the variable intake solenoid (VIS) hose (A).

6.	Disconnect the wiring harness connector (A).

Remove the intake shield (A).

Tightening torque :

7.8 ~ 9.8 N.m (0.8 ~ 1.0 kgf.m, 5.8 ~ 7.2 lb-ft)

Remove the cooling fan assembly (A).

Tightening torque :

4.9 ~ 7.8 N.m (0.5 ~ 0.8 kgf.m, 3.6 ~ 5.8 lb-ft)

9.	Install in the reverse order of removal.

Resistor

1.	Disconnect the battery negative terminal.

2.	Disconnect the wire harness connector (A) and the fan motor connector (B).

Remove the resistor (A) from the cooling fan shroud.

Tightening torque :

1.8 ~ 2.5 N.m(0.18 ~ 0.25 kgf.m, 1.3 ~ 1.8 lb-ft)

4.	Install in the reverse order of removal.

Disassembly

Remove the cooling fan (A) from the cooling fan assembly.

Tightening torque:

2.8 ~ 3.2 N.m (0.28 ~ 0.33 kgf.m, 2.0 ~ 2.4 lb-ft)

Disconnect the fan motor connector (A) from the resistor and then remove the fan motor (B).

Tightening torque:

3.9 ~ 5.9 N.m (0.4 ~ 0.6 kgf.m, 2.9 ~ 4.3 lb-ft)

3.	Assemble in the reverse order of disassembly.

Inspection

Fan Motor

1.	Disconnect the fan motor connector from the resistor.

2.	Connect the battery voltage to the "+" terminal and ground to "-" terminal.

3.	Check the cooling fan motor operates well.

Radiator Components and Components Location

Components

1. Radiator assembly
2. Radiator upper mounting bracket
3. Mounting insulator

4. Radiator lower hose quick connector
5. Radiator upper hose
6. Filler neck assembly

Radiator Repair procedures

Inspection

Radiator Cap Testing

1.	Remove the radiator cap, wet its seal with engine coolant, and then install it on a pressure tester.

2.	Apply a pressure of 93.16 ~ 122.58 kPa (0.95 ~ 1.25 kgf/cm?, 13.51 ~ 17.78 psi).

3.	Check for a drop in pressure.

4.	If the pressure drops, replace the cap.

Radiator Leakage Test

1.	Wait until engine is cool, then carefully remove the radiator cap and fill the radiator with engine coolant, then install it on the pressure tester.

2.	Apply a pressure tester to the radiator and apply a pressure of 93.16 ~ 122.58kpa (0.95 ~ 1.25kg/cm?, 13.51 ~ 17.78psi).

3.	Inspect for engine coolant leaks and a drop in pressure.

Remove the tester and reinstall the radiator cap.

•	Check for engine oil in the coolant and/or coolant in the engine oil.

Removal and Installation

1.	Drain the coolant. (Refer to Cooling System - "Coolant")

2.	Remove the cooling fan. (Refer to Cooling System - "Cooling Fan")

3.	Remove the radiator upper hose (A).

Remove the Radiator lower hose quick connector (A).

•	When the hose detached, remove the holder clip (A) and then disconnect the quick connector.

5.	Remove the front bumper cover. (Refer to Body - "Front Bumper Cover")

Remove the radiator upper mounting brackets (A).

Tightening torque :

7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

[LH]

[RH]

7.	Remove the resonator. (Refer to Intake And Exhaust System - “Air Cleaner”)

8.	Remove the A/C condenser from the radiator assembly.

9.	Remove the radiator assembly (A) from the vehicle.

10.	Install in the reverse order of removal.

11.

Fill the radiator with coolant and check for leaks.

(Refer to Cooling System - "Coolant")

•	Bleed air from the cooling system.

-	(Refer to Cooling System - "Coolant")

Water Temperature Control Assembly Components and Components Location

Components

1. Water temperature control assembly
2. Engine coolant temperature sensor

3. Throttle body coolant hose (if equipped)

Water Temperature Control Assembly Repair procedures

Removal and Installation

1.	Remove the engine cover. (Refer to Engine And Transaxle Assembly - “Engine Cover”)

2.	Drain the engine coolant so its level is below water temperature control assembly. (Refer to Cooling System - "Coolant")

3.	Remove the air duct and air cleaner assembly. (Refer to Intake And Exhaust System - “Air Cleaner”)

4.	Disconnect the radiator upper hose (A).

5.	Disconnect the heater hoses (A).

6.	Disconnect the bypass hose (A) and the throttle body coolant hose (B) (if equipped).

Remove the water temperature control assembly (A) with the O-ring .

Tightening torque:

9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)

•	Install a new O-ring.

•	Clean surface on the O-ring and install the O-ring after wetting with water.

8.	Install in the reverse order of removal.

9.	Fill the engine coolant. (Refer to Cooling System - "Coolant")

10.	Start engine and check for leaks.

Water pump Components and Components Location

Components

1. Water pump pulley
2. Water pump

3. Water pump gasket

Water pump Repair procedures

Removal and Installation

1.	Drain the coolant. (Refer to Cooling System - "Coolant")

2.	Remove the drive belt. (Refer to Timing System - “Drive Belt”)

Remove the water pump pulley (A).

Tightening torque:

9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)

Remove the water pump assembly (A) with the gasket (B).

Tightening torque:

9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)

Install in the reverse order of removal.

•	Install a new water pump gasket.

6.	Fill the engine coolant. (Refer to Cooling System - "Coolant")

7.	Start the engine and check for leaks.

8.	Recheck the coolant level.

Inspection

1.	Check each part for cracks, damage or wear, and replace the coolant pump assembly if necessary.

2.	Check the bearing for damage, abnormal noise and sluggish rotation, and replace the coolant pump assembly if necessary.

Check for coolant leakage. If coolant leaks from hole, the seal is defective. Replace the coolant pump assembly.

•	A small amount of "weeping" from the bleed hole is normal.

Water pump Troubleshooting

Troubleshooting

Symptoms

Possible Causes

Remedy

Coolant leakage

•	From the bleed hole of the water pump

Visually check

•	Check leaks after about ten-minute warming up.

•	If coolant still leaks, replace a water pump.

•	If leakage stops, reuse the water pump (Do not replace the pump with a new one).

•	From gaskets or bolts

•	Check the tightening of the water pump mounting bolts.

•	Retighten the mounting bolts.

•	Check damage of gaskets or inflow of dust.

•	Replace the gasket and clean dust off.

•	From outer surface of water pump

•	Check the material or any cracks of the water pump.

•	Poor material. If any crack found, replace the water pump.

Noise

•	From bearings

•	From mechanical seals

•	Impeller interference

Inspection with a stethoscope

•	After starting the engine, check noise with a stethoscope.

•	If there is no noise, reuse the water pump (do not replace it).

•	If there is any noise from the water pump, remove the drive belt and recheck.

Inspection after removing a drive belt

•	After removing a water pump and a drive belt, check noise again.

•	If there is noise, reuse the water pump. Check other drive line parts.

•	If there is no noise, replace the water pump with a new one.

Inspection after removing a water pump

•	After removing a water pump and a drive belt, check noise again.

•	If there is any interference between them, replace the water pump with a new one.

Overheating

•	Damaged impeller

•	Loosened impeller

Loosened impeller

•	Corrosion of the impeller wing

•	Check engine coolant.

•	Poor coolant quality / Maintenance check

•	Impeller seperation from the shaft

•	Replace the water pump.

Electric Thermostat (ECT) Description and Operation

Description and Operation

Electric Thermostat (ECT)

Overview

Optimal control of coolant temperature depending on the driving conditions

Operation Principle

Electric Thermostat Structure

Electric Thermostat (ECT) Schematic Diagrams

Circuit Diagram

Electric Thermostat (ECT) Components and Components Location

Components

1. Water inlet fitting & Thermostat
2. Bypass hose

3. Heater pipe & hose assembly

Electric Thermostat (ECT) Repair procedures

Removal and Installation

•	Disassembly of the thermostat would have an adverse effect, causing a lowering of cooling efficiency. Do not remove the thermostat, even if the engine tends to overheat.

Thermostat

1.	Drain engine coolant so its level is below thermostat. (Refer to Cooling System - "Coolant")

Disconnect the Radiator lower hose quick connector (A).

•	When the hose detached, remove the holder clip (A) and then disconnect the quick connector.

Remove the water inlet fitting and thermostat (A).

Tightening torque :

18.6 ~ 23.5 N.m (1.9 ~ 2.4 kgf.m, 13.7 ~ 17.4 lb-ft)

Install in the reverse order of removal.

•	Install the thermostat with the jiggle valve upward.

•	When assembling the thermostat, place the thermostat on the housing with a protrusion of thermostat matching with a groove of the housing and install the inlet fitting. Be careful the thermostat doesn’t get out of the groove on the housing.

•	Clean surface on the rubber packing contact surface.

5.	Fill the engine coolant. (Refer to Cooling System - "Coolant")

6.	Start the engine and check for leaks.

7.	Recheck the coolant level.

Heater Pipe

1.	Remove the intake manifold. (Refer to Intake and Exhaust System - "Intake Manifold")

2.	Disconnect the bypass hose (A).

Unfasten the heater pipe mounting bolts (A) and then remove the heater pipe.

Tightening torque :

19.6 ~ 23.5 N.m (2.0 ~ 2.4 kgf.m, 14.5 ~ 17.4 lb-ft)

•	Do not reuse the seal bolts.

4.	Install in the reverse order of removal.

5.	Fill the engine coolant. (Refer to Cooling System - "Coolant")

6.	Start the engine and check for leaks.

7.	Recheck the coolant level.

Inspection

Thermostat

Immerse the only thermostat part in water and gradually heat the water.

•	Don’t immerse connector part.

Check the valve opening temperature.

If the valve opening temperature is not as specified, replace the thermostat.

Valve opening temperature:

100 ± 2°C (212 ± 35.6°F)

Full opening temperature: 115°C (239°F)

Check the valve lift.

If the valve lift is not as specified, replace the thermostat.

Valve lift : 8 mm (0.3 in.) or more at 115°C (239°F)

Electric Thermostat (ECT) Troubleshooting

Troubleshooting

Symptoms

Possible Causes

Remedy

Coolant leakage

•	From the thermostat gasket

Check the mounting nuts

•	Check the torque of the mounting nuts

•	Retighten the bolts and check leakage again.

Check the gasket for damage

•	Check gasket or seal for damage

•	Replace gaskets and reuse the thermostat.

Cooled excessively

•	Low heater performance (cool air blows-out)

•	Thermogauge indicates 'LOW'

Visually check after removing the radiator cap.

•	Insufficient coolant or leakage.

•	After refilling coolant, recheck.

GDS check&Starting engine

•	Check DTCs

•	Check the fan motor performance as temperature varies.

•	Check connection of the fan clutch or the fan motor.

? If the fan clutch is always connected, there will be a noise at idle.

•	Check the engine coolant sensor, wiring and connectors.

•	Check the fan motor, the relay and the connector.

•	Replace the componants.

Remove the thermostat and inspect

•	Check if there are dusts or chips in the thermostat valve.

•	Check adherence of the thermostat.

•	Clean the thermostat valve and reuse the thermostat.

•	Replace the thermostat, if it doesn't work properly.

Heated excessively

•	Engine overheated

•	Thermogauge indicates 'HI'

Visually check after removing the radiator cap.

•	Insufficient coolant or leakage. ? Be careful when removing a radiator cap of the overheated vehicle.

•	Check air in cooling system.

•	After refilling coolant, recheck.

•	Check the cylinder head gaskets for damage and the tightening torque of the mounting bolts.

GDS check&Starting engine

•	Check DTCs

•	Check the fan motor performance as temperature varies.

•	Check if the fan clutch slips.

•	Check the water pump adherence or impeller damaged.

•	Check the engine coolant sensor, wiring and connectors.

•	Check the fan motor, the relay and the connector.

•	Replace the fan clutch, if it doesn't work properly.

•	Replace the water pump, if it doesn't work properly.

Immerse the thermostat in boiling water and inspection.

•	After removing the thermostat, check it works properly.

? Check the thermostat opens at the valve opening temperature.

•	Replace the thermostat, if it doesn't work properly.

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