Remove the engine oil pan guard.
Disconnect the oil pressure sensor connector.
The type of tips used in measuring oil pressure are shown in the figure.
- H4J, K4M: (G) + (C) + (F).
- M4R: Oil pressure measuring nipple (Mot. 1658) + (F).
Install an oil pressure measuring kit in place of the oil pressure sensor (Mot. 836-05) with a suitable tip using a 22 mm socket for removing and installing oxygen sensors (Mot. 1495-01) or a high head of 22 mm.
Start the engine.
Monitor the oil pressure as the engine warms up (to approximately 80°C or until the electric fan of the engine cooling system first turns on), and it should not be lower than at idle.
If the oil pressure is below idle pressure, make sure that:
- the oil filter is not clogged;
- there are no contaminants 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 the fittings from the nipples.
Install the oil pressure sensor. Wipe off any oil leaks with a rag. Wait at least 10 minutes. Check the engine oil level using the dipstick. If necessary, top up the oil level to the norm.
Start the engine and check for oil leaks from the oil pressure sensor.