Fault Phenomenon: Shantui DH46 exhaust is normal when cold. During heavy-load uphill driving (operating temperature), black smoke comes from the exhaust, power is insufficient, and speed is eventually limited.

Troubleshooting Process:
– Checked air filter: element clean, no blockage.
– Checked turbocharger: boost pressure normal.
– Checked injection timing: timing marks aligned.
– Measured intake manifold pressure at operating temperature: found low pressure.

Root Cause: The turbocharger wastegate is stuck in the open position, causing insufficient boost pressure.

Required Parts: Turbocharger assembly or wastegate actuator.