Mitsubishi Diesel Engines SQ-series

This service manual is written to familiarize you with the maintenance of your S4Q, S4Q2 Diesel Engine. If the engine is carefully maintained it will deliver a long productive life and efficient performance marked by power and economy.
Before you attempt to inspect, disassemble, or repair the engine, read this manual carefully to learn more about the engine and how to care for it properly. All descriptions, illustrations, specifications, and serial numbers in this manual are effective as of the date printing of this manual.
The information contained in this manual applies to the engine model produced at the time of publication.
It should be noted that specifications and design may change due to improvements made thereafter.

Table of Contents:

• GENERAL
  •     1 OUTLINE
  •     2 SPECIFICATIONS
• GENERAL INSTRUCTIONS
  •     3 DETERMINATION OF OVERHAUL TIMING
  •     4 TESTING THE COMPRESSION PRESSURE
  •     5 TIPS ON DISASSEMBLY AND REASSEMBLY
  •     6 PRECAUTIONS FOR DISASSEMBLY AND REASSEMBLY
• ENGINE MAIN PARTS
  •     7 CYLINDER HEADS AND VALVE MECHANISM
  •     8 FLYWHEEL
  •     9 TIMING GEARS, CAMSHAFT AND OIL PAN
  •     10 PISTONS, CONNECTING RODS, CRANKSHAFT AND CRANKCASE
• INLET AND EXHAUST SYSTEM
  •     11 DESCRIPTION
  •     12 DISASSEMBLY, INSPECTION AND REASSEMBLY
• COOLING SYSTEM
  •     13 DESCRIPTION
  •     14 WATER PUMP, FAN
  •     15 THERMOSTAT
• FUEL SYSTEM
  •     16 DESCRIPTION
  •     17 FUEL SYSTEM BLEEDING
  •     18 DISASSEMBLY
  •     19 FUEL INJECTION TIMING CHECK
  •     20 FUEL FILTER (PAPER-ELEMENT CARTRIDGE TYPE)
  •     21 FUEL INJECTION NOZZLES
• LUBRICATION SYSTEM
  •     22 DESCRIPTION
  •     23 OIL PUMP
  •     24 OIL FILTER
  •     25 PRESSURE RELIEF VALVE
• ELECTRICAL SYSTEM
  •     26 GENERAL
  •     27 STARTER
  •     28 ALTERNATOR
  •     29 ETR type stop solenoid
  •     30 GLOW PLUGS
• TESTING AND ADJUSTING
  •     31 BENCH TEST
  •     32 IDLING SPEED AND MAXIMUM SPEED SETTING INSPECTION AND ADJUSTMENT
  •     33 PERFORMANCE TEST
• TROUBLESHOOTING
  •     34 CAUSES OF ENGINE PROBLEMS AND REMEDIES
• MAINTENANCE STANDARDS
  •     35 MAINTENANCE STANDARDS TABLE
  •     36 TIGHTENING TORQUES
  •     37 THREAD SEALANTS
  •     38 MAINTENANCE SCHEDULE
• SPECIAL TOOLS
  •     39 SPECIAL TOOL LIST