How to check lubrication system?

To inspect the engine lubrication system, three aspects need to be addressed: oil quality, mechanical components, and pressure parameters. If the oil appears black, turbid, or contains metal particles, it indicates the need for replacement (recommended every 5,000 kilometres or six months). When replacing the filter, apply oil to the new filter's sealing ring and hand-tighten it by 3/4 turn. For critical pressure testing, use a dedicated pressure gauge. With the engine preheated to 3000 rpm, normal oil pressure should maintain 0.3-0.45 MPa. If abnormal, check the gear pump clearance (standard clearance between the external gear and pump housing is 0.12-0.20 mm) or the pressure relief valve (opening pressure 0.35-0.45 MPa). Daily monitoring can utilize the dashboard oil warning light, though note that sensor malfunctions may trigger false alarms - in such cases, employ substitution method for verification. During routine maintenance, it's advisable to concurrently inspect the crankcase ventilation system to prevent oil degradation from exhaust gas condensation.