2. Start the engine and check whether the oil pressure is low or normal using the pressure gauge on the car or the oil level indicator light. Listen to the sounds of the valves operating in sequence or to their knocking.
3. Check the following:
- Is the oil diluted with moisture or mixtures of unburned fuel?
- Is the engine oil viscosity appropriate for the expected temperature?
- Is the oil pressure gauge sensor accurate and in good condition?
- Is the oil pressure gauge accurate and in good working order?
- Is the oil filter clogged?
- Is the oil filter bypass valve working properly?
- Remove the oil pressure sensor from the oil filter adapter.
- Install the KM-135 oil pressure gauge adapter and the KM-498-B oil pressure gauge in place of the oil pressure switch.
- Start the engine and then allow the engine to reach normal operating temperature.
- Measure the engine oil pressure at idle speed.
- The minimum oil pressure should be 200 kPa (29 psi).
4. If the engine oil pressure falls below the minimum specification, check the engine, paying attention to the following possible causes:
- The oil pump is worn out or dirty
- The oil pump safety valve has failed
- The oil pump protective cover is loose, clogged or damaged
- Excessive bearing clearance
- Cracked, porous or blocked oil passages
- The oil passage plugs in the engine block are missing or incorrectly installed
- The valve lifters are broken
- The oil filter adapter is not properly secured
5. After checking the oil pressure, remove the oil pressure gauge and adapter, then set the oil pressure switch to 40 N·m (30 lb-ft).
6. Check the oil level. If necessary, add oil up to the MAX mark.
Information taken from the official website: ChevyMan.ru