The Mitsubishi S12A2 is a 33.9 L 12-cylinder turbocharged engine rated at 1800 rpm, producing up to 500 kW. It powers generator sets from Mitsubishi, including the SIZA2. It holds 100 L (26.4 gal) of oil.
Also known as: Mitsubishi S12A2
Part of the Mitsubishi S12A2 engine family — 11 variants share parts & fitment.
| Oil capacity | 100.0 L |
|---|---|
| Displacement | 33.9 L |
| Cylinders | 12 |
| Aspiration | turbocharged |
| Rated speed | 1800 rpm |
| Gross power | 500 kW |
| Code | Meaning |
|---|---|
| d | Excessive blowby through breather due to worn cylinder liners, pistons, etc. |
| A | A |
| GAIN | GAIN |
| D | D |
| I | I |
| Symptom | Cause | Remedy |
|---|---|---|
| Battery discharged | Check alternator (2D . drive belt, Consult your Mitsubishi dealer, Recharge, Change. | |
| Starter will crank engine, but engine will not start. | Fuel system issues | Refuel, Check connection, Fuel pipe defective (Bad quality fuel) > Change fuel. Air in fuel system > Prime. Consult your Mitsubishi dealer. Fuel filter clogged > Clean or repair. Fuel pipe restricted or leaky > Clean or repair. Fuel feed pump defective > Consult your Mitsubishi dealer. Air & EArAustoy systems Air cleaner clogged > Clean element. Fuel injection pump detective > Consult your Mitsubishi dealer. |
| Air motor will not run. | Low air pressure, Defective starter switch, Defective magnetic valve broken connections | Operate the compressor to increase the pressure in the air tank. Repair broken wires. Consult your Mitsubishi dealer. |
| Air motor runs, but pinion gear will not be engaged with ring gear. | Damaged ring gear or pinion gear | Consult your Mitsubishi dealer. |
| Pinion gear is engaged with ring gear, but ring gear will not rotate. | Low air pressure | Run the compressor to increase the pressure in the air tank. |
| Engine lacks power. | Oil viscosity incorrect, Bad quality fuel, Insufficient air (air cleaner element clogged), Radiator overcooled | Change oil. Change fuel. Clean or change. Use radiator cover or consult your Mitsubishi dealer. |
| Engine overheats. | Radiator and/or heat exchanger dirty, V-belts too loose, Not enough coolant in cooling system, Water pump defective, Thermostat defective | Clean heat exchanger or consult your Mitsubishi dealer. Readjust. Refill. Consult your Mitsubishi dealer. Consult your Mitsubishi dealer. |
Fault codes and symptom→remedy steps extracted from this engine’s service/owner documentation; verify against the official manual before servicing.
| Part # | Description | Category |
|---|---|---|
| 300204 | adjusting screw (5) | adjusting_screw |
| 300517 | adjusting screw (1) | adjusting_screw |
| 300082 | Speed control lever | air_filter |
| 300085 | Speed control lever | air_filter |
| 300086 | Air cleaner (air-motor starting) | air_filter |
| 300089 | Air cleaner indicator (paper-element type) | air_filter |
| 300096 | Air filter (air-motor starting) | air_filter |
| 300100 | Air filter (direct-air starting) | air_filter |
| 300103 | Air cleaner (oil-bath type) | air_filter |
| 300104 | Air cleaner case | air_filter |
| 300111 | Air filter (silencer type) | air_filter |
| 300115 | Air cleaner element (paper-element type) | air_filter |
| 300116 | Air filter element (direct-air starting) | air_filter |
| 300092 | Air tank (air-motor/direct-air starting) | air_tank |
| 300097 | Air tank (air-motor/direct-air starting) | air_tank |
| 300030 | Battery | battery |
| 300090 | Battery | battery |
| 300112 | Fan/water pump/alternator drive belt | belt |
| 300101 | Anti-freeze solution | coolant |
| 300107 | Exhaust muffler | exhaust_muffler |
| 300098 | Primary fuel filter (wire-element type) | fuel_filter |
| 300099 | Secondary fuel filters (paper-element type) | fuel_filter |
| 300122 | new cartridge, old cartridge | fuel_filter |
| 300519 | apply oil to gasket of a new cartridge. bring gasket into contact with sealing face of bracket, and tighten remove case, and wash dust particles off element | fuel_filter |
| 300939 | primary fuel filter (wire-element type) — wash element | fuel_filter |
| 300087 | Fuel tank | fuel_tank |
| 300094 | Fuel tank | fuel_tank |
| 300046 | use clean multi-purpose grease for your engine | grease |
| 300109 | New oil in clean jug, Old oil out of drain plug | oil_change |
| 300106 | Bypass oil filter | oil_filter |
| 300114 | Governor oil filter (Woodward type) | oil_filter |
| 300084 | Oil pan | oil_pan |
| 300108 | Oil pan | oil_pan |
| 300088 | Oiler (air-motor starting) | oiler |
| 07-01 | CRANKCASE ASS~ | other_service |
| 300004 | Daily Operation Record | other_service |
| 300910 | Safety Information Sheet | other_service |
| 300949 | Camshaft Rocker shaft | other_service |
| 300950 | Water jacket | other_service |
| 300952 | Intercooler (left side) | other_service |
| 500001 | other_service | |
| 99260-20160 | other_service | |
| SCR25 | Mitsubishi SCR system | other_service |
| 300110 | Water pump tension pulley | pulley |
| 300102 | Rust inhibitor | rust_inhibitor |
| 300105 | Silencer (precleaner) | silencer |
| 300947 | max. speed setting | speed_setting |
| 300948 | Turbocharger | turbocharger |
| 300091 | Valves in pipeline | valve |
| 300113 | Zinc rods (sea-water cooling) | zinc_rods |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.
The Mitsubishi S12A2 engine has an oil capacity of 100.0 liters.
The Mitsubishi S12A2 has a displacement of 33.9 liters with 12 cylinders.
The Mitsubishi S12A2 powers 1 generator set(s), including Mitsubishi SIZA2.