Engine Oil Pressure: Testing and Inspection

Oil pressure and oil pressure switch, checking





Special tools, equipment, test and inspection devices; required accessories

- VAG 1342 Oil pressure tester
- VAG 1527 B Diode test lamp
- VAG 1594 A Supplemental measuring tool set

Function of the Dynamic Oil Pressure Warning System
The oil pressure switch is open without pressure and is closed when the operating pressure is reached.
The oil pressure warning is actuated approx. 10 seconds after the ignition is turned on.
Oil pressure warning turn-on delay: approx. 3 seconds.
Oil pressure warning turn-off delay: approx. 5 seconds.

Checking the indicator light for operation with oil pressure
After the ignition is turned on, the indicator light (K3) in the instrument panel must light for approx. 3 seconds and then extinguish. The test ends when the engine starts running.

Warning criteria
Warning is provided both visually (blinking indicator light) and acoustically (buzzer sounds three times). This occurs under the following operational states:
- Ignition ON, engine stopped, oil pressure switch closed
- Engine speed above 1500/min, oil pressure switch open

Note:
- The indicator light is not switched off if the engine speed exceeds 5000 rpm, not even if the oil pressure switch is closed. The indicator light will be shut off again when the engine speed drops below 5000 rpm.
- If the oil pressure switch is only opened for 0.5 - 3.0 seconds when the engine speed is over 1500 rpm, this fact will be stored in the instrument cluster processor. If this state occurs three times while the engine is running, the warning will be triggered and will not be cleared even under 500 rpm. The warning will be cleared when the oil pressure switch is closed for more than 5 seconds and the ignition is turned off

Test conditions
- Oil level OK.
- Indicator lamp for oil pressure (K3) must illuminate for approx. 3 seconds after the ignition is turned on.
- Oil temperature at least 80°C

Oil pressure switch, checking





- Remove 1.4 bar oil pressure switch (F1) (black insulation) and screw it into tester.
- Screw tester into oil filter housing in place of oil pressure switch.
- Ground tester brown lead (-).
- Connect VAG 1527 B diode test lamp to battery positive terminal (+) and to oil pressure switch using the auxiliary cables from VAG 1594 A. Light-emitting diode (LED) should not illuminate.
If the LED illuminates:
- Replace 1.4 bar oil pressure switch (F1)
If the LED does not illuminate:
- Start engine and let idle. Light-emitting diode should light at 1.2 - 1.6 bar. Otherwise, replace 1.4 bar oil pressure switch F1).

Oil pressure, checking
Test condition
- The VAG 1342 oil pressure test instrument is not connected
- Oil temperature at least 80 0 C

Test sequence
- Start engine and let it idle.
Specification: oil pressure: at least 2.0 bar
- Increase engine speed.
- The oil should be at least 2.0 bar at 2000 rpm and 80° C oil temperature.
- The oil pressure may not exceed 7.0 bar
- Replace oil pump if necessary.