Fault Phenomenon: LiuGong HBT80A exhaust is normal when cold. After high-load pumping (operating temperature), blue smoke comes from the exhaust, engine oil consumption is high, and eventually power drops.

Troubleshooting Process:
– Checked air filter: element clean, no blockage.
– Checked turbocharger: rotor turns freely, no sticking.
– Checked valve stem seals: good sealing when cold.
– Measured cylinder compression pressure at operating temperature: found low compression pressure in one cylinder.

Root Cause: Piston rings align or break due to heat, causing oil to bypass into the combustion chamber.

Required Parts: Engine piston ring set.