Engine Oil Pressure: Testing and Inspection

Oil pressure and oil pressure switch, checking





Special tools
^ VAG 1342 Oil pressure tester
^ VAG 1527 B Voltage tester
^ VW 1594 Adaptor kit

Oil pressure warning system, function
The oil pressure switch is open when no pressure is applied. The switch closes as soon as the specified pressure has been reached.
The oil pressure warning is activated approx. 10 seconds after the ignition is switched on.
The switch-on delay of the oil pressure warning is approx. 3 seconds.
The switch-off delay of the oil pressure warning is approx. 5 seconds.

Oil pressure warning light, checking
After switching on the ignition, the oil pressure warning light -K3- in the instrument cluster must light up for approx. 3 seconds and then go out. The check is ended when the engine is running.

Warning conditions
Triggering of the optical oil pressure warning (blinking of the oil pressure warning light) and the three-time sound of the buzzer as an audible signal occurs under the following operational conditions:
^ Ignition on, engine not running, oil pressure switch closed.
^ Engine speed higher than 1500 rpm, oil pressure switch closed.

Note:
^ If the engine speed is higher than 5000 rpm, the warning light is not switched off, even when the oil pressure switch is closed. The warning light switches off again below 5000 rpm.
^ If the oil pressure switch is open for only 0.5 to 3.0 seconds at an engine speed over 1500 rpm, this will be stored in the instrument cluster control module. If the condition happens three times while the engine is running, the oil pressure warning is triggered immediately and it does not go out even under 1500 rpm. Erasing of the oil pressure warning occurs when the oil pressure switch is closed longer than 5 seconds and when the ignition is switched off.

Test conditions
^ Engine oil level is OK. Checking
^ Oil pressure warning light -K3- must light up for 3 seconds when the ignition is switched on.
^ Engine oil temperature must be at least 80°C (176°F).

Oil pressure switch, checking





- Remove 0.7 bar oil pressure switch -F1- (brown) and thread into tester.
- Thread tester into filter bracket in place of pressure switch.
- Connect brown tester wire to Ground.
- Connect VAG 1527B voltage tester between battery B+ and oil pressure switch using jumper wires from VW 1594 adaptor kit.
If LED lights up:
- Replace 1.4 bar oil pressure switch -F1-.
If LED does not light up:
- Start engine and run at idle.
^ At 0.55 to 0.85 bar the LED must light up. If not, replace 0.7 bar oil pressure switch -F1-.

Oil pressure, checking
Test conditions
^ Oil pressure tester VAG 1342 is still connected
^ Engine oil temperature at least 80°C (176°F).
^ Oil pressure tester VAG 1342 is still connected

Test sequence:
- Start engine and run at idle.
- Increase engine speed to approx. 2000 rpm.
^ Specified value: Oil pressure at least 2.5 bar
If the value is not reached:
- Replace oil filter bracket with oil pressure valve, or oil pump.
^ At higher rpm the oil pressure of 7.0 bar must not be exceeded.
- If necessary, replace oil filter bracket with oil pressure valve.