Isuzu 4HK1 — Cylinder head assembly removal

Repair & overhaul

For the Isuzu 4HK1, from the Isuzu service manual.

Applies to: Isuzu 4HK1

Procedure

1. Disconnect the battery ground cable from the battery.
2. Drain the coolant from the radiator; after discharge make sure to tighten the drain plug.
3. Disconnect the engine harness connectors from the engine assembly.
4. Remove the air cleaner duct, air intake hose, exhaust pipe, oil feed pipe, oil return pipe, water return pipe and water feed pipe from the turbocharger.
5. Remove the exhaust manifold stay from the cylinder block and the turbocharger assembly.
6. Disconnect the harness connector and remove the turbocharger assembly from the exhaust manifold.
7. Remove the box-shaped or cylindrical EGR cooler assembly: disconnect the water rubber hose and remove the EGR heat protector, EGR pipes and coolers.
8. Remove the EGR valve from the EGR pipe D.
9. Remove the EGR cooler water pipe from the engine assembly.
10. Remove the intake throttle valve from the inlet pipe and disconnect its harness connector.
11. Disconnect the boost sensor, boost temperature sensor, EGR valve and IMT sensor connectors, then remove the inlet pipe from the case.
12. Remove the oil level gauge from the guide tube and remove the guide tube from the cylinder block.
13. Remove the glow plug connector and the glow plug from the cylinder head assembly.
14. Remove the injection pipe from the injector and common rail; do not reuse the removed injection pipe.
15. Remove the fuel pipe, fuel leak-off pipe assembly and common rail assembly.

Full service-parts list: Isuzu 4HK1 →

Source: Isuzu service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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