Sensors and valves (Hyundai Sonata EF)

Contents: Checking the pressure reducing valve ⇓ Checking the engine oil pressure…⇓

Checking the pressure reducing valve

1. At low crankshaft speeds, the pressure relief valve closes the bypass channel under the action of the spring. At high speeds, the oil pressure increases, the oil pressure force overcomes the spring force, the pressure relief valve opens, and excess oil returns through the bypass channel back to the oil pan.

2. Checking the pressure reducing valve.

a) Using a wooden rod, press the valve plunger and check that the plunger moves to its original position without sticking. If the valve plunger is found to be stuck, replace the valve.
b) Check the condition of the pressure reducing valve spring (no breakage or deformation).

Checking the engine oil pressure switch and its circuit

1. Check that the low engine oil pressure indicator comes on when the ignition is turned on (ignition switch in the "ON" position) and then goes out when the engine is cranked by the starter or the engine is idling.

The material was obtained from a web resource HyundaiBook

Note: If the low engine oil pressure indicator does not come on, the bulb may be burned out or the wiring may be faulty.

Engine oil pressure when the engine is idling (oil temperature 75-90°C):

2.0L/2.4L engines: 80 kPa
2.7L engine: 50 kPa or more

2. Checking the engine oil pressure switch sensor.

a) Using an ohmmeter, check for a closed circuit between the terminal and the body of the sensor-switch. If the circuit is open, replace the sensor-switch.
b) Insert a thin rod (or wire) into the hole of the sensor-switch and push it in slightly. If the circuit is closed between the terminal and the body of the sensor-switch when the rod is inserted, replace the sensor-switch.
c) If the circuit between the terminal and the body of the sensor-switch is open when a pressure of 50 kPa acts on the diaphragm of the sensor-switch through the hole, then the sensor-switch is in good condition.
d) Check for air pressure leaks. If there are air pressure leaks, the diaphragm is damaged. Replace the switch sensor.

Switch sensor response pressure:

2.0L/2.4L engines: 14.7-29.4 kPa
2.7L Engine: 20-40 kPa

3. Install the engine oil pressure switch.

Apply the specified sealant to the threads of the oil pressure switch sensor, then use a socket (24 mm) to install it to the cylinder block (2.0L/2.4L engines) or oil pan (2.7L engine) and tighten the sensor to the specified torque.