Hyundai Sonata LF: Cooling System / Thermostat Repair procedures

Hyundai Sonata LF 2014-2019 Service Manual / Engine Mechanical System / Cooling System / Thermostat Repair procedures

Removal

Disassembly of the thermostat would have an adverse effect, causing a lowering of cooling efficiency.

1.	Drain engine coolant so that its level would be under the thermostat height.

2.	Remove the radiator lower hose. (Refer to Cooling System - "Radiator Hose")

3.	Remove the water inlet fitting (A) and thermostat (B).

Inspection

1.	Immerse the thermostat in water and gradually heat the water.

Check the valve opening temperature.

Valve opening temperature:

82±1.5°C (179.6±2.7°F)

Full opening temperature: 95°C (203°F)

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

Check the valve lift.

Valve lift : 8mm(0.3in) or more at 95°C (203°F)

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

Installation

1.	Place the thermostat in the block. Install the thermostat (B) with the jiggle valve upward.

Install the water inlet fitting (A).

Tightening torque :

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

3.	Fill with engine coolant.

4.	Start engine and check for leaks.

Thermostat Components and Components Location

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Thermostat Troubleshooting

Troubleshooting SymptomsPossible CausesRemedyCoolant leakage • From the thermostat gasket Check the mounting bolts • Check the torque of the mounting bolts • Retighten the bolts and check leakage again...

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