2004 Mitsubishi SL-Series Diesel Engine Service Manual (P/N MHI-E-SLSERIES)

This Mitsubishi SL-Series service manual, version 08/2004, covers the S3L, S3L2, S4L, and S4L2 diesel engines and their S3L-T, S3L2-T, S4L-T, and S4L2-T turbocharged variants. Shallow and deep oil pan configurations are included.

Text search and wiring detail: The PDF has searchable text and embedded bookmarks for chapters and individual procedures. Small wiring labels require zooming; the ETR diagram has lighter lines and labels that need closer viewing.

• Engine repair: Cylinder-head and valve service, crankshaft and piston inspection, bearing installation, timing gear assembly, and cylinder-head bolt tightening sequences.

• Fuel injection: Bosch M pump disassembly and reassembly, throttle-type nozzle testing, injection timing adjustment with shims, and centrifugal governor torque spring installation.

• Starting and charging: Starter and alternator inspection, repair procedures, starter no-load testing, and automatic glow system checks.

• Engine shutdown: Separate ETS and ETR key shutoff solenoid sections, wiring diagrams, connection details, and installation procedures.

• Cooling and lubrication: Water pump and thermostat inspection, thermoswitch and thermounit testing, trochoid oil pump checks, and pressure relief valve inspection.

• Fault diagnosis and service data: Symptom-based troubleshooting charts, compression testing, wear limits, component torque tables, fluid capacities, and electrical test specifications.

The repair procedures suit diesel technicians and experienced engine rebuilders who can use precision measuring equipment, presses, electrical test instruments, and fuel-injection test equipment.

Engine Diagnosis and Internal Repair

Dedicated troubleshooting charts address hard starting, fuel knock, overheating, black exhaust smoke, erratic idle speeds, and low power. Separate starting-system charts cover faults such as failure to crank, pinion engagement problems, and starter overrun.

The overhaul assessment explains why hard starting or reduced power alone does not establish a need for an engine rebuild. Its comparison of compression loss, oil consumption, and blowby helps distinguish internal wear from fuel-system or starting-system faults before major repair work is planned.

Internal inspection extends to valve guides and seats, combustion jets, camshafts, tappets, piston rings, connecting rods, crankshaft journals, and cylinder bores. The manual documents valve-seat refacing, cylinder reconditioning, undersize bearing options, timing gear backlash, and crankshaft end play.

Assembly illustrations show bearing-cap orientation, piston and ring positioning, timing marks, and seal installation. The piston installation section identifies how forcing the assembly into the bore can damage the rings and crankpin.

Bosch M Injection Pump, Nozzles, and Governor

Pump coverage includes plungers, barrels, delivery valves, tappets, control sleeves, and the control rack, with inspection points and checks after assembly. The governor section covers flyweights, the sliding sleeve, linkage, springs, and torque spring set installation.

Nozzle procedures include valve-opening pressure testing, the orifice restriction test, nozzle-tip cleaning, and replacement. Injection timing coverage describes both the fuel-flow inspection method and an alternate method, followed by shim-based adjustment.

The pump assembly section warns that excessive delivery-valve holder tightening can load the barrels and prevent free plunger movement. Fuel-system repair also requires attention to the manual’s injection-spray precautions and eye-protection warnings.

Electrical Testing and Shutdown Variants

Starter repair includes armature, brush, commutator, and overrunning-clutch inspection, plus testing after assembly. Alternator coverage addresses the rotor, stator, rectifier, brushes, and reassembly precautions.

Separate ETS and ETR wiring diagrams help match fault tracing to the installed shutdown system. Solenoid connection information distinguishes energize-to-stop operation from the ETR pull-in and hold-in circuits. The automatic glow section provides timer and relay specifications and glow-plug inspection.

Cooling, Lubrication, and Routine Service

Cooling system, lubrication system, fuel system, and air inlet system schematics show component relationships. Component location views distinguish the engine layouts, while inspection illustrations support water pump, manifold, and oil pressure switch checks.

Maintenance coverage includes valve clearance, idle-speed setting, fan belt adjustment, and fuel-system priming for both the filter with an AIR valve and the cartridge filter with air vent screws. Turbocharger maintenance is referred to a separate turbocharger manual.

Repair Specifications and Special Tools

Service data includes standard dimensions, wear limits, electrical test values, tightening torques, and sealant applications. Certain application-dependent values refer to the applicable engine model specification sheet.

Listed tools include piston pin setting tool 31A91-00100, camshaft bushing installer ST332340, compression gauge adaptor ST332270, and oil pressure switch socket wrench MD998054.

Printable PDF and Included Pages

The English manual is supplied as one printable, 195-page PDF. That total already includes the introduction, contents, chapter divider pages, and the final page labeled “BLANK PAGE.”