Checking oil pressure and pressure sensor (VW Polo 3)

1. Unscrew the pressure sensor (0.25 bar, blue) and screw it into the tester (Fig. 6.39).



2. Screw the tester adapter into the hole for the pressure sensor in the cylinder head.

3. Connect the brown wire 3 of the tester to the "-".

4. Connect the VAG 1527 diode tester with an additional wire to the "+" of the battery and terminal A of the pressure sensor. The tester light should light up.

5. Start the engine and slowly increase the engine speed. At a pressure of 0.15-0.45 for the blue sensor (0.25 bar) the light should go out, otherwise replace the sensor.

6. Connect the diode tester to terminal B of the brown pressure sensor (0.9 bar). At a pressure of 0.15-0.35 bar the tester light should light, otherwise replace the sensor.

7. Slowly increase engine speed. At 2000 rpm and 80°C the pressure should be 2.0 bar. At high crankshaft speeds the oil pressure should not exceed the limit of 7 bar. If necessary, replace the oil pump cover with bypass valve.