Caterpillar C6.6 ACERT Engine
The Caterpillar C6.6 ACERT is a 6.6 L 6-cylinder ta engine rated at 1800 rpm, producing up to 168 kW. It powers generator sets from Caterpillar, including the D125, D150 and D175. It holds 11.5 L (3.0 gal) of oil and 15.5 L (4.1 gal) of coolant.
Also known as: Caterpillar C6.6 ACERT
Service parts for the C6.6 ACERT
The cheapest captured merchant offer per filter — see the full cross-reference below for every OEM/aftermarket option.
Air intake
1 required2525001Air filterfind
Prices captured from merchant listings; some links are affiliate links. Verify against your serial number before ordering.
Engine specifications
| Oil capacity | 11.5 L |
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| Coolant capacity | 15.5 L |
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| Displacement | 6.6 L |
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| Cylinders | 6 |
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| Aspiration | TA |
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| Rated speed | 1800 rpm |
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| Gross power | 168 kW |
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Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Air filter with monitoring system | | — | | |
| Fuel filter | Cat high efficiency fuel filters with Stay-Clean Valve, primary and secondary filters in engine compartment | | 1466695 | | Amazon eBay $35.86 FridayParts $33.99 |
| Oil filter | Caterpillar air filter for engine compartment | | — | | |
| Battery | | | — | | |
| Belt | | | — | | |
| Coolant | Extended Life Coolant or conventional heavy-duty coolant | | — | | |
| Spark plug | | | — | | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Service intervals
1| Item | Action | Hours | Months | Notes |
|---|
| Engine oil filter | Replace | 512 hr | | Last changed 6/10/24, 512HRS |
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
1| Type | Item | Value | Unit | Condition |
|---|
| Voltage | DC Voltage | 13.8 | V | load bank test, all stages |
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 | Capacity | Notes |
|---|
| Fuel | | LCV = 42700 kJ/kg | | | MaK technical data; without engine-driven pumps, tolerance 5% |
| Fuel | 35° API gravity at 60°F (16°C) | LHV 18,390 Btu/lb (42 780 kJ/kg) | | | Fuel at 85°F (29°C) weighing 7.001 lbs/U.S. gal (838.9 g/liter) |
| Fuel | EPA 2D 89.330-96 | | | | Density 0.845 – 0.850 kg/L (7.052 – 7.094 lbs/U.S. gal.) @ 15°C (59°F); fuel inlet temperature 40°C (104°F); fuel rates based on this specification |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
1Load Bank Test diagnostic
Tools: Load bank
- Warm up
- Start and record no-load readings
- Apply load and record readings at 15 min
- Record readings at 30 min
- Record readings at 45 min
- Record readings at 1 hour
- Cool down and record readings
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 2525001 Caterpillar 2525002 Caterpillar 1282686 Caterpillar 6I2502 Caterpillar 2567902 Caterpillar 2567903 Donaldson P635904 Donaldson P635980
- Fuel filter: Caterpillar 1165436 Caterpillar 1466695 Donaldson P550625 Donaldson P553205 Wix 33640 Baldwin BF7753 Wix 33675 Baldwin BF1350-SP
- Fuel filter (primary): Caterpillar 1466695 Donaldson P553205 Wix 33675 Baldwin BF1350-SP
- Oil filter: Caterpillar 4621171 Caterpillar IR1807 Caterpillar 3890434 Donaldson P550920 Donaldson P551807 Donaldson P551808 Wix 57325 Baldwin B7378
Cross-referenced via Donaldson + OEM/engine-maker interchange — options to verify against your serial number, not confirmed for every exact variant.
Also used in
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- Caterpillar 953D — Loader Tracked
- Caterpillar 963D — Loader Tracked
- Caterpillar CP56 — Compactor
- Caterpillar CP64 — Compactor
- Caterpillar CP74 — Compactor
- Caterpillar D6N LGP — Tractor Tracked
- Caterpillar D6N XL — Tractor Tracked
- Claas LEXION 510 — Combine
- Claas LEXION 520 — Combine
- Claas LEXION 520 MONTANA — Combine
- Claas LEXION 540C — Combine
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 C6.6 ACERT?
The Caterpillar C6.6 ACERT engine has an oil capacity of 11.5 liters.
What is the displacement of the Caterpillar C6.6 ACERT?
The Caterpillar C6.6 ACERT has a displacement of 6.6 liters with 6 cylinders.
Which generators use the Caterpillar C6.6 ACERT engine?
The Caterpillar C6.6 ACERT powers 3 generator set(s), including Caterpillar D125, Caterpillar D150, Caterpillar D175.
What oil filter does the Caterpillar C6.6 ACERT use?
The Caterpillar C6.6 ACERT uses oil filter part numbers Caterpillar 4621171, Caterpillar IR1807, Caterpillar 3890434.
What fuel filter does the Caterpillar C6.6 ACERT use?
The Caterpillar C6.6 ACERT uses fuel filter part numbers Caterpillar 1165436, Caterpillar 1466695, Donaldson P550625.
What air filter does the Caterpillar C6.6 ACERT use?
The Caterpillar C6.6 ACERT uses air filter part numbers Caterpillar 2525001, Caterpillar 2525002, Caterpillar 1282686.