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Caterpillar C18 ACERT Engine

The Caterpillar C18 ACERT is a 18.1 L 6-cylinder ta, tta engine rated at 1800 rpm, producing up to 448 kW. It powers generator sets from Caterpillar, including the AD45, C18 and XQ570. It holds 26.9 L (7.1 gal) of oil and 26.9 L (7.1 gal) of coolant.

Also known as: Caterpillar C18 ACERT

18.1 L

Displacement

Cylinders

1800 rpm

Rated speed

448 kW

Gross power

On this pageService parts Specs Generator sets Maintenance Filter cross-reference FAQ Service intervals Torque & specs Fluids Procedures

Service parts for the C18 ACERT

The cheapest captured merchant offer per filter — see the full cross-reference below for every OEM/aftermarket option.

Air intake

1 required

1063973Air filter$39.31eBay

Fuel system

2 required

1165436Fuel filtersee priceAmazon

1165436Fuel filter (secondary)see priceAmazon

Oil system

1 required

3890434Oil filter$30.97PartsGeek

Prices captured from merchant listings; some links are affiliate links. Verify against your serial number before ordering.

Engine specifications

Oil capacity	26.9 L
Coolant capacity	26.9 L
Displacement	18.1 L
Cylinders	6
Aspiration	TA, TTA
Rated speed	1800 rpm
Gross power	448 kW

Generator sets powered by this engine

Caterpillar AD45Caterpillar C18 Caterpillar XQ570

How to read your Caterpillar engine serial & model number →

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	500-hour oil change intervals		—	500 hr
Fuel filter	500-hour oil change intervals		—	500 hr
Oil filter	500-hour oil change intervals		3890434	500 hr	Amazon eBay $82.42 PartsGeek $30.97 NAPA $45.70
Battery	500-hour oil change intervals		—	500 hr
Belt	500-hour oil change intervals		—	500 hr
Coolant	500-hour oil change intervals	100.7 L	—	500 hr
Oil	500-hour oil change intervals	74.0 L	—	500 hr
Spark plug	500-hour oil change intervals		—	500 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
Engine oil (S-O-S oil sample)	Test	125 hr		Severe service occurs at high loads, in high temperatures, and in dusty conditions
Coolant (S-O-S coolant analysis Level 1)	Test	250 hr		Cat ELC - Every 250 Hours; also the recommended sampling interval for all conventional heavy-duty coolant/antifreeze and for commercial coolants that meet Cat EC-1
Engine crankcase oil (S-O-S oil sample)	Test	250 hr		Table 6 S-O-S Oil Sampling Interval; severe applications may require a more frequent oil sampling interval
Primary air filter element	Change	250 hr		When changing the primary element at 250 operating hours (basis of the without-indicator filter-change comparison)
SCA (Supplemental Coolant Additive) concentration	Test	250 hr		Test the concentration of SCA or submit a coolant sample at 250 hour intervals or at PM Level 1 intervals; check at every oil change or every 250 hours, whichever occurs first
Coolant (S-O-S coolant analysis Level 2)	Test	500 hr	12 mo	First service — For new systems, refilled systems, and converted systems that use Cat ELC or Cat DEAC; also every year; use the interval that occurs first
engine	Other	500 hr		Cat compact diesel lineup offers 500-hour maintenance intervals and single-side service access
oil	Change	500 hr		3000 Series service intervals increased to 500 hours as standard (3013C, 3024C, 3054, 3056)
Secondary air filter element	Change	750 hr		When changing the secondary element at 750 operating hours (basis of the without-indicator filter-change comparison)
Cat ELC Extender addition (cooling system)	Other	6000 hr		Treat the cooling system with Cat ELC Extender at 6000 hours or one half of the coolant service life
Coolant (Cat ELC)	Change	12000 hr		12000 service hours or six years; use the interval that occurs first
minor overhaul	Other	20000 hr		3600 engines designed to run 20 000 hours between minor overhauls using No. 2 fuel
major overhaul	Other	40000 hr		3600 engines designed to run 40 000 hours between major overhauls using No. 2 fuel
cylinder liners and pistons	Other	80000 hr		3600 cylinder liners and pistons designed for 80 000 hours using No. 2 fuel
Coolant (S-O-S coolant analysis Level 1 and Level 2)	Test		12 mo	Cat DEAC - Yearly

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Other	Arr. Number	3149714
Other	Bore	145.0	mm (5.71 in)
Other	Compression ratio	16.3:1
Other	Displacement	18.1	L (1,104.53 in3)
Other	Emissions certification	U.S. EPA Tier 2 and CARB; FM approved; UL listed - US and Canada; Meets NFPA 20 requirements
Other	Engine dimension (1) Length	1889.0	mm (74.37 in)	Do not use for installation design
Other	Engine dimension (2) Width	1091.0	mm (42.95 in)	Do not use for installation design
Other	Engine dimension (3) Height	1379.7	mm (54.32 in)	Do not use for installation design
Other	Feature Code	C18DF03
Other	Gross Input Torque (TH55-E70)	12 667	N•m (9350 lb-ft)
Other	Gross Input Torque (TH55-E90)	12 677	N•m (9350 lb-ft)
Other	Net dry weight (approximate)	1769	kg (3900 lb)
Other	Performance Number	EM0022-01
Other	Radiator cooling package design ambient temperature	48.9	°C (120° F)	with 50/50 water/Extended Life Coolant mixture
Other	Radiator cooling package maximum elevation	1524	m (5000 ft)	with 50/50 water/Extended Life Coolant mixture
Other	Rating condition (diesel 7 L and higher)	99 kPa (29.31 in Hg) dry barometer, 25°C (77°F)		SAE J1995 inlet air standard
Other	Rating condition (diesel up to 6.6 L)	100 kPa (29.5 in Hg) total barometric pressure, 1 kPa (.295 in Hg) vapor pressure, 25°C (77°F)		ISO/TR14396 inlet air standard
Other	Rating condition (gas)	100 kPa (29.61 in Hg) and 25°C (77°F)		SAE J1349 standard
Other	Rating condition - inlet air standard conditions	99 kPa (29.31 in. Hg) dry barometer
Other	Stall Torque Ratio (TH55-E70)	2.23
Other	Stall Torque Ratio (TH55-E90)	2.23
Other	Stroke	183.0	mm (7.2 in)
Other	Weight, Net Dry (approximate)	1673	kg (3688 lb)
Other	Weight, Net Dry (approximate)	1769	kg	approximate
Pressure	Oil pressure	65-69		at 600 kW load
Pressure	Unit injector fuel injection pressure	1240	bar (18 000 psi)
Pressure	WS255 pump plunger load	238,000	lb (107,960 kg)
Pressure	WS273XD pump plunger load	275,000	lb (124 738 kg)
Pressure	WS305XD pump plunger load	250,000	lb (113 398 kg)
Speed	Frequency	60	Hz
Speed	Maximum Input Speed (TH55-E70/TH55-E90 transmissions)	1970	rpm
Speed	Rated Input Speed (TH55-E70/TH55-E90 transmissions)	1900	rpm
Speed	Rated engine speed	2100	rpm	rated power 597 kW / 800 bhp
Speed	Rotation (from flywheel end)	Counterclockwise
Temperature	Ambient temperature	65-66	°F
Temperature	Coolant temperature	189-190	°F	at 600 kW load
Temperature	Radiator DELTA-T	38	D
Temperature	Rating condition - inlet air temperature	25	degC (77 degF)
Torque	Air compressor SAE "A" hydraulic pump drive maximum torque (374 L/min and 467 L/min compressors)	60	N•m (44 lb-ft)	C7, C9 ACERT
Voltage	DC voltage	27.1	V

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Notes
Coolant	50/50 mixture water/Caterpillar Extended Life Coolant		below 48°C	Radiator cooling packages designed for up to 48.9° C (120° F) ambient; coolant sump refill capacities vary by oil sump/pan (18 L to 106 L service refill with new oil filter change)
Coolant	Cat DEAC			Diesel; 3,000 Service Hours or Three Years; annual S·O·SSM Level 2 coolant sampling and analysis
Coolant	Cat DEAC (Diesel Engine Antifreeze/Coolant)	Acceptable coolant; commercial heavy-duty antifreeze/coolant must meet ASTM D4985 or ASTM D6210		Conventional heavy-duty coolant/antifreeze. Caterpillar recommends a 1:1 mixture of water and glycol. Do not use a commercial coolant/antifreeze that only meets the ASTM D3306 specification. Do not use Cat SCA at the initial fill when Cat DEAC is used.
Coolant	Cat ELC			Diesel; 12,000 Service Hours or Six Years; add Cat ELC Extender at 6,000 service hours or one half of service life; annual S·O·SSM Level 2 coolant sampling and analysis
Coolant	Cat ELC (Extended Life Coolant)	Caterpillar EC-1 specification (preferred); also meets ASTM D4985, ASTM D6210, and ASTM D3306		Service life of 12000 service hours or six years. Premixed ELC provides freeze protection to -37 C (-34 F); ELC Concentrate can be used to lower the freezing point to -52 C (-62 F). An Extender is the only additional maintenance needed at 6000 service hours or one half of the ELC service life. Cat ELC cooling systems can withstand contamination to a maximum of ten percent of conventional heavy-duty coolant/antifreeze and/or SCA.
Coolant	Cat NGEC			Natural Gas; 16,000 Service Hours or Three Years; use interval that occurs first
Coolant	Cat SCA (Supplemental Coolant Additive) with water			SCA concentration in a cooling system that uses SCA and water should be six to eight percent by volume; do not exceed the eight percent maximum concentration. If Cat SCA is not used, the commercial SCA must provide a minimum of 2400 mg/L or 2400 ppm (140 grains/US gal) of nitrites in the final coolant mixture when used with water, and a minimum of 1400 mg/L or 1400 ppm (82 grains/US gal) with heavy-duty coolant/antifreeze.
Coolant	Glycol (ethylene glycol / propylene glycol)	Propylene glycol coolant must meet ASTM D6210-04		Ethylene glycol: 50 percent = freeze protection -37 C (-34 F), boil protection 106 C (223 F); 60 percent = -52 C (-62 F), 111 C (232 F). Propylene glycol: 50 percent = -32 C (-26 F), 106 C (223 F). Do not use propylene glycol in concentrations that exceed 50 percent; do not use ethylene glycol in concentrations that exceed 60 percent. All Caterpillar diesel engines equipped with air-to-air aftercooling (ATAAC) require a minimum of 30 percent glycol.
Engine oil		EPA 2D 89.330-96 (fuel reference, Diesel <6.6 L, density 0,845-0,850 kg/L a 15 °C)		Reference condition only, not a lubricant recommendation
Engine oil	Cat DEO (Diesel Engine Oil) 10W-30 and 15W-40	Cat ECF-1 (exceeds); API CI-4, API CI-4 PLUS, API CH-4, API CG-4, API CF (Cat DEO SAE 15W-40)		Caterpillar oils are used to fill diesel engines at the factory. Non-Caterpillar commercial oils are second choice oils. Do not use API CF-4 oils in Caterpillar diesel engines. Do not use single grade API CF oils or multigrade API CF oils in 3500 Series, C175 Series and smaller DI diesel engines.
Engine oil	Cat NGEO			Natural Gas
Engine oil	Commercial oils (DI engines)	Cat ECF-1 required; API CG-4 multigrade acceptable; API CH-4, API CI-4 and API CI-4 PLUS acceptable only if the requirements of Cat ECF-1 are met; do not use API CF-4 oils		Minimum TBN must be 10 times the fuel sulfur level (ASTM D2896); minimum TBN of the oil is 5 regardless of a low fuel sulfur level. API CG-4 oils: do not exceed the standard oil drain interval.
Engine oil	Commercial oils (PC engines)	Cat ECF-1; API CH-4, API CI-4, API CI-4 PLUS (if Cat ECF-1 requirements met); API CG-4 multigrade; API CF-4 multigrade; API CF		Minimum TBN of the oil that is used in PC engines must be 20 times the fuel sulfur level; minimum TBN of new oil is five. Change the oil when the TBN deteriorates to 50 percent of the original TBN.
Engine oil	Re-refined base stock oils			Acceptable if they meet the performance requirements specified by Caterpillar; filtering is inadequate for producing high quality re-refined base stock oils.
Engine oil	Synthetic base stock oils			Acceptable if they meet the performance requirements specified for the engine compartment. Caterpillar does not recommend the automatic extension of oil drain intervals for any type of oil.
Engine oil	Cat Arctic DEO SYN SAE 0W-30		-40°C to 30°C	Engine Crankcase; Industrial Engines
Engine oil	SAE 0W-20		-40°C to 10°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	SAE 0W-30		-40°C to 30°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	SAE 0W-40		-40°C to 40°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	Cat DEO SYN SAE 5W-40		-30°C to 50°C	Engine Crankcase; Industrial Engines
Engine oil	SAE 5W-30		-30°C to 30°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	SAE 5W-40		-30°C to 50°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	Cat DEO SAE 10W-30		-18°C to 40°C	Engine Crankcase; Industrial Engines
Engine oil	SAE 10W-30		-18°C to 40°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines); SAE 10W-30 is the preferred viscosity grade for the 3116, 3126, C7, C-9 and C9 diesel engines between -18 C (0 F) and 40 C (104 F)
Engine oil	SAE 10W-40		-18°C to 50°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	Cat DEO SAE 15W-40		-9°C to 50°C	Engine Crankcase; Industrial Engines
Engine oil	SAE 15W-40		-9°C to 50°C	Table 1 Lubricant Viscosities for Ambient Temperatures (DI diesel engines)
Engine oil	Cat SAEO SAE 30	API CF-4 category	0°C to 40°C	Table 2 - 3116 and 3126 Marine Engines with mechanical unit injection; factory fill has API CF-4 category and viscosity grade of SAE 30
Engine oil	SAE 30		0°C to 40°C	Table 3 Lubricant Viscosities for Ambient Temperatures - PC engines only
Engine oil	Cat SAEO SAE 40	API CF-4 category	5°C to 50°C	Table 2 - 3116 and 3126 Marine Engines with mechanical unit injection. Caterpillar does not recommend the use of multigrade oils in the 3116 and 3126 Marine Diesel Engines that use mechanical unit injection.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Determining the cause of a plugged fuel filter (ice or wax) diagnostic

Remove the fuel filters.
Cut the fuel filters open.
Inspect the fuel filter before the filter warms. The inspection will show that the filter is filled with particles of either ice or wax.

Changing to Cat ELC maintenance

⚠ Do not leave an empty SCA maintenance element on a system that is filled with ELC. The element housing may corrode and leak causing an engine failure.

⚠ Improper or incomplete rinsing of the cooling system can result in damage to copper and other metal components.

⚠ The cooling system cleaner must be thoroughly flushed from the cooling system. Cooling system cleaner that is left in the system will contaminate the coolant. The cleaner may also corrode the cooling system.

Tools: Caterpillar cleaner for cooling systems, 5P-3413 Pipe Sealant, Suitable containers to collect fluids

Drain the coolant into a suitable container.
Dispose of the coolant according to local regulations.
If equipped, remove the empty SCA maintenance element and the element base. Plug the coolant lines or bypass the coolant lines.
Flush the system with clean water in order to remove any debris.
Use Caterpillar cleaner for cooling systems in order to clean the system. Follow the instructions on the label.
Drain the cleaner into a suitable container. Flush the cooling system with clean water.
In systems with heavy deposits, disconnect the hoses. Clean deposits and debris from the hoses and fittings. Install the hoses and tighten the hose fittings.
Fill the cooling system with clean water and operate the engine until the engine is warmed to 49 C to 66 C (120 F to 151 F).
Drain the cooling system into a suitable container and flush the cooling system with clean water.
Repeat Steps 8 and 9 until the system is completely clean.
Fill the cooling system with the Cat ELC.
Operate the engine until the engine is warmed. While the engine is running, inspect the engine for leaks. Tighten hose clamps and connections in order to stop any leaks.
Attach the Special Publication, PEEP5027, "Label" to the cooling system filler for the engine in order to indicate the use of Cat ELC.

Calculating the amount of lighter fuel required to modify the cloud point or the pour point operation

Obtain the specification for the cloud point or the pour point of both fuels from your fuel supplier.
Locate the cloud point or the pour point of the heavier fuel on the left side of the table. Mark the point on the table.
Locate the cloud point or the pour point of the lighter fuel on the right side of the table. Mark the point on the table.
Draw a line between the two points that were established. Label this line "A".
Find the lowest outside temperature for machine operation on the left side of the table. Draw a horizontal line from this point until it intersects line "A". Label this new line "C".
Mark the intersection of line "C" and line "A". Draw a vertical line to the bottom of the table. Label this line "B". The point at the bottom of line "B" reveals the percentage of lighter fuel that is

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Filters for this engine

Air filter: Caterpillar 1063973 Caterpillar 1327169 Caterpillar 1236856 Caterpillar 30009151 Caterpillar 2310167 Caterpillar 6I0274 Donaldson P533884 Donaldson P538007
Fuel filter: Caterpillar 1165436 Caterpillar 3089679 Caterpillar 3890433 Donaldson P550625 Donaldson P551311 Donaldson P551316 Wix 33640 Baldwin BF7753
Fuel filter (secondary): Caterpillar 1165436 Caterpillar 3089679 Donaldson P550625 Donaldson P551311 Wix 33640 Baldwin BF7753 Wix 33674NP Baldwin BF7587
Oil filter: Caterpillar 3890434 Donaldson P551808 Wix 57792 Baldwin B7299

Cross-referenced via Donaldson + OEM/engine-maker interchange — options to verify against your serial number, not confirmed for every exact variant.

Also used in

Caterpillar 385C — Excavator Tracked
Caterpillar 385CL — Excavator Tracked
Caterpillar 385CMHPU — Power Unit
Caterpillar 390F — Excavator Tracked
Caterpillar 390FL — Excavator Tracked
Caterpillar 651 — Tractor
Caterpillar 657 — Tractor
Caterpillar 772 — Dump Truck
Caterpillar 836H — Compactor
Caterpillar D9 — Dozer Tracked
Caterpillar D9T — Tractor Tracked
New Holland FR9080 — Harvester

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.

Common questions

What is the oil capacity of the Caterpillar C18 ACERT?

The Caterpillar C18 ACERT engine has an oil capacity of 26.9 liters.

What is the displacement of the Caterpillar C18 ACERT?

The Caterpillar C18 ACERT has a displacement of 18.1 liters with 6 cylinders.

Which generators use the Caterpillar C18 ACERT engine?

The Caterpillar C18 ACERT powers 3 generator set(s), including Caterpillar AD45, Caterpillar C18, Caterpillar XQ570.

What oil filter does the Caterpillar C18 ACERT use?

The Caterpillar C18 ACERT uses oil filter part numbers Caterpillar 3890434, Donaldson P551808, Wix 57792.

What fuel filter does the Caterpillar C18 ACERT use?

The Caterpillar C18 ACERT uses fuel filter part numbers Caterpillar 1165436, Caterpillar 3089679, Caterpillar 3890433.

What air filter does the Caterpillar C18 ACERT use?

The Caterpillar C18 ACERT uses air filter part numbers Caterpillar 1063973, Caterpillar 1327169, Caterpillar 1236856.

How often should you change the oil in the Caterpillar C18 ACERT?

The Caterpillar C18 ACERT oil change interval is every 500 hours.