What year 6.7 Cummins to stay away from?
There isn’t a single year you should universally avoid. Overall reliability is solid, but early generations carried more teething issues with emissions controls and maintenance complexity. With proper care and complete service history, most years can be a good buy.
Context: how the 6.7 Cummins evolved over time
The 6.7-liter Cummins inline-six has powered Ram trucks since 2007 and has gone through several updates. Buyer decisions should hinge on maintenance records and current condition as much as on the year itself. Below is a year-by-year style guide to help gauge risk and reliability based on reported trends and common wear items.
2007–2009: Early generation with emissions-controls teething issues
The first years of the 6.7 Cummins represent the transition to modern diesel emissions systems. The following points summarize what buyers often see in this window.
- Higher incidence of emissions-system related faults (EGR-related problems and related cooling leaks) reported by some owners.
- Fuel-system and injector-related service needs were more common as the technology matured.
- Maintenance costs can be higher if the truck has not been kept up with regular service history.
Conclusion: If you’re considering a 2007–2009 model, expect to verify service history thoroughly and be prepared for potential emissions-related repairs. A well-documented example with recent EGR/cooling work can still be a solid pick.
2010–2012: Refinements with fewer widespread issues
This window saw improvements as the platform matured, though high-mileage examples still demand caution. Here’s what buyers typically assess in this era.
- General reliability remains solid, but wear items (turbo, hoses, seals) at higher mileage can drive maintenance costs.
- Fuel and exhaust-system components are generally more mature; verify service records for any turbo or exhaust work.
- DEF/low-pressure fuel system reliability improves with proper maintenance, but failures can still occur if neglected.
Conclusion: 2010–2012 can be good choices, especially with complete maintenance history. They’re often more affordable than newer trucks while offering solid reliability when cared for.
2013–2018: Refresh era with improved reliability
A significant mid-cycle refresh addressed many earlier concerns, and these years are commonly recommended for a used 6.7 Cummins. Buyers should still perform standard due-diligence checks.
- Overall reliability tends to be notably better than the earliest years, thanks to updated components and refinements.
- Maintenance history remains crucial; look for documented cooling-system service, injector maintenance, and any EGR-related work performed proactively.
- Defensive checks for common wear items (cooling hoses, intercooler piping, and gaskets) are still wise, but systemic failures are less frequent than in 2007–2009 models.
Conclusion: 2013–2018 is often viewed as a sweet spot for used 6.7 Cummins buyers, balancing price with a history of improved reliability. A well-maintained example is typically a strong performer.
2019–present: Modern emissions era with ongoing maintenance needs
The latest generation aligns with current emissions frameworks and ongoing diesel technology improvements. Here are the key considerations for these newer trucks.
- DEF/DPF systems are integral; ensure the exhaust aftertreatment has been inspected and well-maintained.
- Recalls and service campaigns should be checked; verify with the dealer that all updates have been performed.
- Maintenance intervals and wear items (injectors, seals, turbo, cooling system) still matter, but ongoing reliability tends to be good if kept up-to-date.
Conclusion: 2019–present models can be very reliable, particularly when they come with complete service records and a history of timely recalls and maintenance. Expect higher upfront price but strong long-term reliability with proper care.
What to check when buying a used 6.7 Cummins
Before buying, use this checklist to assess condition, regardless of year. A thorough inspection and test drive can reveal hidden issues that a year-only view would miss.
- Full service history, including diesel-grade oil changes and cooling-system work
- Evidence of EGR cooler or cooling-system maintenance, replacements, or leaks
- Turbo, intercooler hoses, and intake components for cracks or oil leaks
- Fuel system service records and evidence of injector or pump servicing if applicable
- Cold-weather starting performance and glow-plug/relay condition
- DEF/DPF system status, regen history, and any related faults
- Cooling system integrity: coolant condition, leaks, thermostat, radiator, and hoses
- Visible oil leaks around the engine and transmission; check for sludge buildup in the valley and on seals
Conclusion: A comprehensive check of maintenance history and a careful road test are essential. Prioritize well-documented vehicles with recent major service work completed.
Bottom line
There isn’t a single year that universally deserves avoidance. The 6.7 Cummins has proven capable and durable across many model years, especially when properly maintained. If you must choose, consider 2013–2018 as a reliable baseline and scrutinize maintenance records for any year. Always have a trusted diesel technician inspect any used truck before purchase.
Summary
In short, the best approach is not to shun a specific year but to evaluate each truck on its maintenance history, service receipts, and current condition. Early 2007–2009 models carry more reported emissions-related issues, while 2013–2018 models tend to offer a favorable balance of price and reliability. Regardless of year, a well-documented service history and a thorough inspection are your strongest safeguards when buying a used 6.7 Cummins.
