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)

• Adapter for VAG 1342 (V.A.G 1342/14)

• Voltage Tester (V.A.G 1527 B)

• Connector Test Set (V.A.G 1594 C)

• Wiring Diagram

Test Conditions

• The engine oil level is OK. Checking, refer to => [ Oil Level, Checking using the ] Testing and Inspection.

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

• The selector lever must be in the "P" or "N" position.

Oil Pressure Switch , Checking

- Remove the oil pressure switch and install it into the oil pressure gauge.






- Install the oil pressure gauge (V.A.G 1342) with the adapter (V.A.G 1342/14) into oil filter housing in place of the oil pressure switch.

• Observe the installed position of the adapter (V.A.G 1342/14) : The conical connection of the adapter is threaded in with the pressure hose of the oil pressure gauge (V.A.G 1342).

- Connect the brown wire from the oil pressure gauge (V.A.G 1342) to ground (-).

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

• While starting the engine, watch the pressure gauge and LED as the switch point of the oil pressure switch may already be exceeded during start up.

- Start the engine and run at idle speed.

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

Oil Pressure, Checking

- Check the oil pressure at different speeds:

• 1500 RPM: at least 1.7 bar

• 2000 RPM: 3.0 to 5.5 bar

• above 2000 RPM: maximum 7.0 bar

If the specified values are not reached:

• Check the suction pipe strainer for contamination.

• Check the control piston of the oil pressure relief valve for contamination.

• Check the oil pipe at the bottom of the cylinder block for leaks.

• Also, mechanical damage, for example, bearing damage can also be the cause of too low oil pressure.

• The control piston for the oil pressure relief valve is spring loaded. Therefore the highest care is required when removing the plug.

• The locking bolt in the oil pump is tightened to 35 Nm.

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.

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