Engine Oil Pressure: Testing and Inspection

Oil Pressure and Switch, Checking

Special tools, testers and auxiliary items required

• Oil Pressure Gauge (V.A.G 1342)

• Voltage Tester (V.A.G 1527 B)

• Connector Test Set (V.A.G 1594 C)

• Socket 24 mm and Jointed Extension (T40175)

• Torque Wrench (5-50 Nm) (V.A.G 1331)

• Vehicle Diagnosis Tester

Test Conditions:

• Engine oil level is OK, checking, refer to => [ Oil Level, Checking ] Testing and Inspection.

• Engine oil temperature is at least 80 °C (176 °F) (coolant fan must start up once).

• For the functional check and servicing of the optical and acoustic oil pressure warning. Refer to and "Function and Component Selection" in the vehicle diagnostic tester.

Test Sequence:

• Tightening specifications, refer to => [ Oil Filter, Oil Cooler and Oil Pressure Switch Overview ] Service and Repair.

- Disconnect the connector from the oil pressure switch (F1).

- Remove the oil pressure switch - 2 - using the socket 24 mm and jointed extension (T40175) and install it in the oil pressure gauge (V.A.G 1342).






- Install the oil pressure gauge (V.A.G 1342) in place of the oil pressure switch into the bracket.

- Connect the brown wire - 1 - from the oil pressure gauge to ground.

- Connect the voltage tester (V.A.G 1527 B) to the battery positive (+) terminal and to the oil pressure switch. Use adapter cables from the connector test kit (V.A.G 1594 C).

• The Light Emitting Diode (LED) must not light up.

If the LED lights up:

- Replace the oil pressure switch.

If the LED does not light up:

- Start the engine and slowly increase engine speed:

• LED must light up at 1.2 to 1.6 bar positive pressure, otherwise replace the oil pressure switch.

- Increase the engine speed (RPM) further:

• At 2000 RPM and an oil temperature of 80 °C (176 °F), the oil pressure should be between 2.7 bar and 4.5 bar.

At higher engine speeds the oil pressure must not exceed 7.0 bar

If the specification is not obtained:

- Make sure the screen inside the oil intake pipe => [ (Item 22) Oil Intake Pipe ] Oil Pan and Pump Overview is not dirty.

• Check for mechanical damage, for example, bearing failures that can cause low oil pressure.

If no malfunction can be found:

- Replace the oil pump. Refer to => [ Oil Pump ] Oil Pump.

If the specification is exceeded:

- Check the oil passages.