Fault Phenomenon: Shantui DH60 engine oil pressure is normal when cold. While idling (operating temperature), the engine oil pressure is too low, the warning light comes on, and eventually engine seizure occurs.

Troubleshooting Process:
– Checked engine oil level: level normal.
– Checked oil filter: filter not clogged.
– Checked oil pump: pump gear wear normal.
– Measured main oil gallery pressure at operating temperature: found pressure below standard.

Root Cause: Excessive wear clearance of the engine main bearings causes severe pressure loss under thermal conditions.

Required Parts: Engine bearings and oil pump.