Part of the Isuzu 6HK1 engine documentation.
This is the Isuzu Service Manual for the 4HK1 and 6HK1 industrial diesel engines, a 907-page PDF you can download and keep on any device. These common rail engines power a wide range of construction and industrial machines, and the manual carries them from engine mechanical work all the way through the electronic engine control system.
Inside you get the full engine mechanical section covering the cylinder head, pistons and connecting rods, crankshaft, and timing gear train, plus dedicated cooling, fuel, electrical, exhaust and turbocharger, and engine control chapters. It includes torque specifications, clearances, compression figures, and the diagnostic trouble code and scan tool procedures with wiring diagrams.
For owners, fleet mechanics, and rebuilders working on 4HK1 or 6HK1 engines, it provides the factory specifications and step by step procedures needed for accurate diagnosis, repair, and overhaul.
Other editions of this manual
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Engine Mechanical | 1-178 | Cylinder Head, Piston & Connecting Rod, Crankshaft, Timing Gear Train |
| Cooling System | 27-52 | Water Pump, Thermostat, Drive Belt, Coolant |
| Fuel System | 53-76 | Common Rail, Fuel Injector, Fuel Supply Pump, Fuel Filter |
| Engine Electrical | 807-870 | Charging System, Starting System, Generator, Preheating System |
| Exhaust System and Turbocharger | 871-894 | EGR System, Turbocharger, Exhaust Manifold, Disassembly and Inspection |
| Engine Control | 877-907 | Diagnostic Trouble Codes (Dtc), Scan Tool Usage, Wiring Diagrams, Sensor Checks |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Turbocharger to exhaust manifold nut torque | 52 N·m (38 lb ft) | p. 29 |
| Connecting rod bearing cap bolt torque | 1st step = 39 N·m (29 lb ft), 2nd step = 60°, 3rd step = 30° | p. 108 |
| Fuel injector clamp bolt torque | 30 N·m (22 lb ft) | p. 96 |
| Fuel supply pump bolt tightening torque | 76 N-m (56 lb ft) | p. 49 |
| Valve clearance (Intake and Exhaust) | 0.4 mm (0.016 in) | p. 6 |
| Piston ring gap (Top ring, Standard) | 0.2 – 0.3 mm (0.0079 – 0.0118 in) | p. 105 |
| Engine coolant temperature for ECM to begin limiting fuel flow | 108°C | p. 26 |
| 4HK1 | ||
| Thermostat valve-opening temperature, 4HK1 | 85 °C (185 °F) | p. 11 |
| Wheel shaft axial play (Standard), 4HK1 | 0.03 – 0.06 mm (0.0012 – 0.0024 in) | p. 28 |
| 6HK1 | ||
| Thermostat valve-opening temperature, 6HK1 | 82 °C (180 °F) | p. 12 |
| Pump shaft and center interference | 0.048 - 0.078 mm (0.0019 – 0.0031 in) | p. 44 |
| Wheel shaft axial play (Standard), 6HK1 | 0.06 – 0.09 mm (0.0024 – 0.0036 in) | p. 28 |
