The Caterpillar C18-C is a 18 L turbocharged engine rated at 2100 rpm. It powers generator sets from Northern Lights, including the M843JK.
Also known as: Caterpillar C18-C
Part of the Caterpillar C18 engine family — 8 variants share parts & fitment.
| Displacement | 18.0 L |
|---|---|
| Aspiration | Turbocharged |
| Rated speed | 2100 rpm |
Compiled from service & troubleshooting documentation across every generator set that uses the Caterpillar C18-C.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Battery electrolyte | Check | 50 hr | 1 mo | First service — After first 50 hours; check every 50 hours or once per month |
| Cylinder head bolts | Adjust | 50 hr | First service — Retighten after first 50 hours | |
| V-belt tension | Check | 50 hr | First service — After first 50 hours | |
| Valves | Adjust | 50 hr | First service — After first 50 hours | |
| Batteries, cables and terminals | Clean | 100 hr | Check and clean every 100 hours | |
| Radiator fins | Clean | 100 hr | Industrial only; clean in very dusty applications | |
| Air cleaner | Check | 200 hr | Every 200 hours; more often in dusty conditions | |
| Engine oil and filter | Change | 200 hr | First service — Every 200 hours | |
| Exhaust elbow | Inspect | 200 hr | Every 200 hours; check for corrosion and exhaust leakage | |
| Primary fuel filter element (Racor) | Change | 200 hr | Every 200 hours or as necessary | |
| Secondary fuel filter | Change | 200 hr | Every 200 hours | |
| Batteries | Test | 600 hr | Check condition with hydrometer every 600 hours | |
| Cooling system | Clean | 600 hr | 12 mo | Flush every 600 hours or every 12 months, whichever comes first |
| Injectors | Check | 600 hr | Every 600 hours by dealer or injection repair station | |
| Raw water pump impeller | Replace | 600 hr | Marine only; every 600 hours or as needed | |
| Valve clearances | Check | 600 hr | Every 600 hours | |
| Fuel injection pump | Check | 2400 hr | Every 2400 hours | |
| Heat exchanger | Clean | 2400 hr | 12 mo | Marine only; once a year or after 2400 hours |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Clearance | V-belt deflection | 3/16 | in | midpoint between crankshaft and alternator pulleys |
| Clearance | V-belt deflection | 5 | mm | midpoint between crankshaft and alternator pulleys |
| Pressure | Coolant filler cap pressure valve | 0.5 | bar | |
| Pressure | Coolant filler cap pressure valve | approximately 7 | PSI | |
| Pressure | Oil pressure | above 15 | PSI | operating |
| Pressure | Oil pressure after a few seconds of operation | 20-60 | PSI | normal reading |
| Temperature | Industrial shutdown temperature | above 110 | °C | shut off engine immediately |
| Temperature | Industrial shutdown temperature | above 230 | °F | shut off engine immediately |
| Temperature | Marine shutdown temperature | above 205 | °F | shut off engine immediately |
| Temperature | Marine shutdown temperature | above 96 | °C | shut off engine immediately |
| Temperature | Water temperature gauge (industrial) | below 107 | °C | operating |
| Temperature | Water temperature gauge (industrial) | below 225 | °F | operating |
| Temperature | Water temperature gauge (marine) | below 200 | °F | operating |
| Temperature | Water temperature gauge (marine) | below 94 | °C | operating |
| Torque | Cylinder head bolts | 60 - 64 | ft/lbs | cold |
| Torque | Cylinder head bolts | 9.0 - 9.5 | kg/m | cold |
| Torque | Delivery lines at injectors | 11-18 | ft./lbs | |
| Torque | Injector | 44 - 51 | ft/lbs | |
| Torque | Injector | 6 to 7 | kgm | |
| Torque | Return line retaining bolts | 22 - 30 | ft/lbs | |
| Torque | Rocker arm cover nuts | 0.8 - 2.3 | kg/m | |
| Torque | Rocker arm cover nuts | 5 - 8 | ft/lbs | |
| Valve clearance | Intake and exhaust valve clearance | 0.008 | in | cold, engine not running |
| Valve clearance | Intake and exhaust valve clearance | 0.2 | mm | cold, engine not running |
| Voltage | DC voltmeter | 11 - 15 | volts | 80°F (25°C) ambient temperature |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Coolant | 50% distilled water / 50% ethylene glycol antifreeze mix | 4.1 liters | Recommended as a good year-round coolant; approx cooling capacity HE 1.1 gal (4.1 liter) | ||
| Engine oil | SAE 5-20W | API Service CC/CD/SF multi-viscosity | below -23°C | Below -10°F (-23°C) | |
| Engine oil | SAE 5W | API Service CC/CD/CE single viscosity | below -23°C | Below -10°F (-23°C) | |
| Engine oil | SAE 10-30W | API Service CC/CD/SF multi-viscosity | -23°C to 0°C | -10 to 32°F (-23 to 0°C) | |
| Engine oil | SAE 10W | API Service CC/CD/CE single viscosity | -23°C to 0°C | -10 to 32°F (-23 to 0°C) | |
| Engine oil | SAE 15-40W | API Service CC/CD/SF multi-viscosity | above 0°C | Above 32°F (0°C) | |
| Engine oil | SAE 30W | API Service CC/CD/CE single viscosity | above 0°C | Above 32°F (0°C) | |
| Fuel | No. 1 diesel | ASTM D975 | below 0°C | Below freezing and all temperatures at altitude above 5,500 ft. (1500 meters) | |
| Fuel | No. 2 diesel | ASTM D975 | above 0°C | Above freezing 32°F (0°C); sulphur less than 1% (preferably less than 0.5%); cetane minimum 45 |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
⚠ Engine should be cold and NOT running.
Tools: Feeler gauge, Wrench
⚠ Do NOT run the engine with the air cleaner removed.
⚠ Battery gas can explode; keep flames and sparks away from batteries.
Tools: Hydrometer
⚠ Escaping diesel fuel under pressure can penetrate skin causing serious personal injury.
⚠ Use cardboard or wood, not hands, to search for suspected leaks.
Tools: Wrench
⚠ Overtightening can damage the filter housing.
Tools: Filter wrench
⚠ Allow engine to cool before working on cooling system.
⚠ Open filler cap carefully using protective clothing when engine is warm.
⚠ Never use flushing oil or additives in crankcase.
⚠ Dispose of waste oil in an approved manner.
Tools: Oil drain container
⚠ Do not overtighten.
Tools: Filter wrench
⚠ Place protection under screwdrivers so pump housing is not damaged.
⚠ Keep an extra impeller and cover gasket in reserve on board.
Tools: Needle-nose pliers or two screwdrivers
Tools: Torque wrench
⚠ Store set in a dry, protected place; if stored outside, protect with a cover.
⚠ Use protective clothing and open the filler cap carefully when the engine is warm to prevent burns.
⚠ The battery switch must always be kept ON while the engine is running.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| 106-3973 | Air filter inner | Air filter |
| 151-7737 | Air Primary | Air filter |
| 189-0202 | Air Secondary | Air filter |
| 1W-3636 | Air Secondary | Air filter |
| 1W-3637 | Air Primary | Air filter |
| 246-5009 | Air | Air filter |
| 246-5010 | Air | Air filter |
| 4N0015 | Air filter outer | Air filter |
| 7C-1571 | Air Primary | Air filter |
| 8N6309 | Air filter outer | Air filter |
| 9Y-3879 | Air | Air filter |
| 6T1395 | Alternator | Alternator |
| 118-2018 | V-belt | Belt |
| 4N6302 | V-belt | Belt |
| M-CK3687817P | Cylinder Kit | Cylinder kit |
| 133-5673 | Fuel/Water Separator | Fuel filter |
| 1R-0749 | Fuel Secondary - ADV | Fuel filter |
| 1R-0762 | Fuel Secondary - ADV | Fuel filter |
| 1R-0770 | Fuel/Water Separator | Fuel filter |
| 1R-0781 | Fuel/Water Separator - ADV | Fuel filter |
| 1R0749 | Filter fuel | Fuel filter |
| 1R0755 | Filter fuel | Fuel filter |
| 326-1641 | Axial seal FWS | Fuel filter |
| 326-1642 | Filter water separator | Fuel filter |
| 326-1643 | Filter water separator | Fuel filter |
| 3S3875 | Filter fuel | Fuel filter |
| 9N3717 | Filter water separator | Fuel filter |
| 4N1151 | Gasket oil pan | Gasket |
| M-4220925 | Gasket Set - Rear Structure | Gasket |
| M-4337629 | Gasket Set - Rear Structure | Gasket |
| M-4351087 | Gasket Set - Rear Structure | Gasket |
| M-4361559 | Gasket Set - Front Structure | Gasket |
| M-4365757 | Gasket Set - Turbo Installation | Gasket |
| M-4452666 | Gasket Set - Rear Structure | Gasket |
| M-4496052 | Gasket Set - Oil Cooler & Lines | Gasket |
| M-4588198 | Gasket Set - Front Structure | Gasket |
| M-4682161 | Gasket Set - Cylinder Head | Gasket |
| M-4685553 | Gasket Set - Central & Lower | Gasket |
| M-4685746 | Gasket Set - Cylinder Head | Gasket |
| M-4687363 | Gasket Set - Water Pump | Gasket |
| M-4687942 | Gasket Set - Turbo Installation | Gasket |
| M-4690626 | Gasket Set - Central & Lower | Gasket |
| M-4690822 | Gasket Set - Turbo Installation | Gasket |
| M-4690823 | Gasket Set - Cylinder Head | Gasket |
| M-4690878 | Gasket Set - Cylinder Head | Gasket |
| M-4692381 | Gasket Set - Central & Lower | Gasket |
| M-4692382 | Gasket Set - Fuel System | Gasket |
| M-4692388 | Gasket Set - Cylinder Head | Gasket |
| M-4701892 | Gasket Set - Turbo Installation | Gasket |
| M-4733264 | Gasket Set - Rear Structure | Gasket |
| M-4886213 | Gasket Set - Oil Cooler | Gasket |
| M-4916359 | Gasket Set - Turbo Installation | Gasket |
| MCB3306031 | MAJOR OVERHAUL GASKET SET | Gasket |
| MCB3306032 | GASKET SET | Gasket |
| MCB3306033 | CYLINDER HEAD GASKET SET | Gasket |
| MCB3306121 | MAJOR OVERHAUL GASKET SET | Gasket |
| MCB3306122 | GASKET SET | Gasket |
| MCB3306123 | CYLINDER HEAD GASKET SET | Gasket |
| M-2572752 | Gasket Set - C18 Front Structure | Gasket set |
| M-3604170 | Gasket Set - C18 Front Structure | Gasket set |
| M-3605916 | Gasket Set - C18 Central & Lower | Gasket set |
| M-4154993 | Gasket Set - Single Cylinder Head - C18 | Gasket set |
| M-4446485 | Gasket Set - C13-C15-C18 Front Structure | Gasket set |
| 126-1815 | Hydraulic - UHE | Hydraulic filter |
| 144-6691 | Hydraulic | Hydraulic filter |
| 1R0774 | Filter hydraulic | Hydraulic filter |
| 328-3655 | Filter hydraulic/transmission | Hydraulic filter |
| 9T0973 | Filter hydraulic/transmission | Hydraulic filter |
| M-2463129 | Impeller – Water Pump | Impeller |
| 102-2828 | Filter oil | Oil filter |
| 1R-0716 | Engine Oil | Oil filter |
| 1R-1808 | Engine Oil - ADV | Oil filter |
| 1R0716 | Filter oil | Oil filter |
| 1R1808 | Filter oil | Oil filter |
| 2243245 | Connecting rod | Service part / kit |
| 249-0439 | Oxidation Catalyst Assembly - Round | Service part / kit |
| 256-0331 | Oxidation Catalyst Assembly - Round | Service part / kit |
| 385C | Hydraulic Excavator | Service part / kit |
| 888-983-7847 | ENGINE BLOCK CRANKSHAFT | Service part / kit |
| A100 | Download Specification | Service part / kit |
| AEXQ1051-00 | Not explicitly stated in the document. | Service part / kit |
| M-3687815 | Piston | Service part / kit |
| M-3687816 | Piston | Service part / kit |
| M-CK3687815P | Kit - Cylinder Kit | Service part / kit |
| M-CK3687816P | Kit - Cylinder Kit | Service part / kit |
| PEDJ0512-01 | Ripper – Single-Shank | Service part / kit |
| R-20R2284 | C15/C18/C27/C32 ACERT Trim file (12-digit serial) | Service part / kit |
| R-20R2285 | C15/C18/C27/C32 ACERT Trim file (12-digit serial) | Service part / kit |
| RSC18E | Ring Set - Piston | Service part / kit |
| RSC18E1 | Ring Set - Piston | Service part / kit |
| M-3687817 | Piston | Piston |
| 138-6744 | Water pump repair kit | Pump |
| 161-4113 | Oil pump | Pump |
| 336-2213 | Water pump | Pump |
| 352-0211 | Water pump | Pump |
| 384-8611 | Lift/transfer pump | Pump |
| 384-8612 | Lift/transfer pump | Pump |
| M-2463130 | Shaft – Water Pump | Pump |
| M-2672839 | Water pump repair kit | Pump |
| M-3848611 | Pump - Transfer | Pump |
| 142-5867 | Front seal | Seal |
| 142-5868 | Rear seal | Seal |
| M-2454630 | Sensor Assembly - Speed | Sensor |
| 247-7133 | Thermostat | Thermostat |
| 248-5513 | Thermostat | Thermostat |
| 420-5855 | Water Pump Seal Installer (Dimensions: 47 x 45 mm, Weight: .463 kg) | Water pump seal installer |
| PA140VS | Winch Model PA140VS | Winch |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.
The Caterpillar C18-C has a displacement of 18.0 liters.
The Caterpillar C18-C powers 1 generator set(s), including Northern Lights M843JK.
A commonly reported issue on generators using the Caterpillar C18-C is: Engine Hard to Start or Will Not Start. Cause: Improper starting procedure. Fix: See starting section of this manual. Take special note of Bypass Switch operation..