Is the Ford 6.4 L diesel a good engine?
Overall, the 6.4 L Power Stroke is a mixed bag: it delivers strong torque for towing, but it has a reputation for reliability challenges and higher maintenance costs compared with Ford’s later diesel line. A well-documented, properly upgraded example can be serviceable, but ownership today often demands careful budgeting for potential repairs.
Background and context
The Ford 6.4 L Power Stroke was produced for the 2008–2010 Ford Super Duty lineup and built under contract with Navistar/International. It’s a turbocharged V8 diesel that delivered about 350 horsepower and roughly 650 lb-ft of torque, aimed at heavy-duty pickup duties and towing. The engine incorporates modern diesel aftertreatment, including a diesel particulate filter and an exhaust gas recirculation system. In Ford’s lineup, it was eventually succeeded by the 6.7 L Power Stroke in 2011, a move widely credited with improving reliability and long-term ownership costs for most buyers.
What makes it appealing
Strengths and capabilities
Before listing the strengths, consider what buyers tend to value in this engine. The 6.4 L offered strong low-end torque and solid towing ability, plus a heavy-duty construction that some fleets appreciate. It also benefits from a robust aftermarket ecosystem, which can support performance tweaks, replacement parts, and maintenance options for those who stay with the platform.
Pros of the 6.4 L Power Stroke include:
- Strong torque suitable for heavy towing and payloads
- Capable mid-range acceleration for a diesel pickup
- Durable, heavy-duty design when properly maintained
- Active aftermarket support and potential for upgrades
- Emissions-compliant with a working diesel particulate filter and EGR system
These positives help explain why some buyers and fleet operators chose the 6.4 L, especially when a good maintenance history is present. However, the engine’s weaknesses are well-documented and influence overall ownership cost and reliability comparisons with newer diesels.
Common issues and maintenance costs
Typical failure points and ownership impact
Before diving into the list, note that the 6.4 L has several components that are well-known trouble spots. Problems in this area are among the primary reasons owners face higher maintenance costs compared with newer diesel platforms.
- Fuel injection and high-pressure fuel system reliability (injectors and related seals)
- FICM (Fuel Injection Control Module) failures affecting starts and drivability
- Oil cooler and EGR cooler reliability, which can lead to leaks or cross-contamination
- Exhaust aftertreatment maintenance, including DPF servicing and potential regeneration issues
- Turbocharger durability and related piping/connectors
- Higher ongoing maintenance costs relative to newer diesel engines
In practice, these issues translate to higher repair bills and more frequent service needs as the vehicle ages, especially if the truck has seen heavy use or insufficient preventive maintenance. Enthusiasts and fleets who invested in updated components often report improved reliability, but that requires additional upfront expenditure.
Reliability and maintenance considerations
Buying or owning a 6.4 L today
For anyone considering a used 6.4 L, the reliability story hinges on maintenance history and whether key updates have been performed. Components such as the HPFP/inkjector assemblies and the FICM have historically been the most expensive failure points. Ford and third-party suppliers released updated parts and service bulletins to address known failures, but parts costs and labor can still be significant. A thorough pre-purchase inspection focusing on the high-pressure fuel system, cooling system, EGR/DPF, and turbo health is essential.
Owners who prioritize preventive maintenance—regular coolant and oil changes, timely injector work, and verified cooling system integrity—tend to experience fewer surprises. Others report that without proactive upgrades, the engine can become expensive to keep on the road, especially as mileage climbs.
Is it a good engine today?
In today’s market, the 6.4 L Power Stroke remains a niche option. It can be a reasonable choice for buyers who find a well-documented, properly upgraded example at a favorable price and who are prepared for potentially higher maintenance costs. For most buyers prioritizing long-term reliability and lower ownership risk, Ford’s 6.7 L Power Stroke or other modern diesel options are typically safer bets in the used-truck segment.
Summary
The Ford 6.4 L diesel delivers solid towing performance and a rugged, heavy-duty feel, but it carries a reputation for reliability challenges and higher maintenance costs tied to its high-pressure fuel system and exhaust aftertreatment. A careful buyer will seek a full service history, look for evidence of component upgrades, and plan for preventive maintenance to mitigate the engine’s known weak points. In the right hands, a well-maintained 6.4 L can still serve as a capable workhorse, but it demands ongoing attention and budgeting for potential repairs.
