Remove the engine undertray.
Disconnect the oil pressure sensor connector.
The type of tips used in measuring oil pressure is shown in the figure.
- H4J, K4M: (G) + (WITH) + (F).
- M4R: oil pressure gauge (Mot. 1658) + (F).
Replace the oil pressure sensor with an oil pressure measuring kit (Mot. 836-05) with a suitable tip using a 22 mm socket for removing and installing oxygen sensors (Mot. 1495-01) or high head 22 mm.
Start the engine.
Monitor oil pressure as engine warms up (up to approximately 80°C or until the first activation of the electric fan of the engine cooling system), which should not be lower than at idle.
If the oil pressure is below idle pressure, check that:
- the oil filter is not clogged;
- there is no contamination or metal filings in the oil;
- the oil pump and its drive are in good condition.
Oil pressure readings on the pressure gauge
Engines H4J, K4M:
- at idle: 0.5 bar;
- at 400 rpm: 3.1 to 4.4 bar.
M4R engine:
- at idle: 0.8 bar;
- 2000 rpm: 4.5 bar.
Stop the engine.
Remove fittings.
Install the oil pressure sensor. Wipe off any oil spills with a rag. Wait at least 10 minutes. Check the engine oil level on the dipstick. Top up the oil level if necessary.
Start the engine and check that there is no oil leakage from the oil pressure sensor.