Common Problems with the 6.7 Power Stroke (and Which Years to Avoid)

The 6.7L Power Stroke is one of the most capable diesel engines ever put in a consumer pickup truck. It is fast, powerful, and when it is running right, it makes towing feel almost effortless. But it also has some well-documented issues that every buyer needs to know about before handing over their money.

We have bought, inspected, and sold hundreds of Power Stroke trucks. Here is the honest rundown of the known problems, which years are affected, and what to look for when you are shopping.

The Direct Answer

Problem 1: The CP4 High-Pressure Fuel Pump (2011 to 2019)

This is the biggest issue with the 6.7L Power Stroke and the one that gets the most attention online. The Bosch CP4.2 high-pressure fuel injection pump is sensitive to fuel contamination and lubricity. When it fails, it does not just stop working. It sends metal shavings through the entire high-pressure fuel system, contaminating the injectors, fuel rails, and lines.

Replacing a fuel system after a CP4 failure typically costs between $8,000 and $15,000 depending on how far the contamination spread. It is one of the most expensive diesel repairs you can face.

Problem 2: Early Turbocharger Design (2011 to 2014)

The first generation of the 6.7L Power Stroke used a unique compound turbocharger setup with a small high-pressure turbo and a large low-pressure turbo working together. The concept was good on paper, but the small high-pressure turbo was prone to premature failure, especially on trucks that were towed hard or tuned.

Ford redesigned the turbocharger system for the 2015 model year, switching to a single variable geometry turbocharger. The 2015 and newer trucks are significantly more reliable in this area.

Problem 3: EGR Cooler and EGR Valve Issues

The Exhaust Gas Recirculation (EGR) system on the 6.7L Power Stroke can cause problems at higher mileages. The EGR cooler can develop internal leaks that allow coolant to mix with exhaust gases, leading to white smoke from the exhaust and potential overheating. The EGR valve itself can also stick or fail, causing rough idle and reduced power.

This is not unique to Ford. Most modern diesel trucks with EGR systems have similar issues at high mileage. The key is to check for any history of EGR-related codes during a pre-purchase inspection.

Problem 4: Cab-Off Repairs

This is less of a mechanical problem and more of a cost-of-ownership issue that catches buyers off guard. The 6.7L Power Stroke is packed very tightly into the engine bay. Several major repairs, including replacing the turbocharger on early models and accessing certain engine components, require the mechanic to physically unbolt and lift the cab off the frame to get proper access.

A cab-off repair adds 8 to 15 hours of labor to what would otherwise be a straightforward job. If you are buying a high-mileage Power Stroke, factor in that some repairs will cost significantly more than they would on a Cummins or Duramax.

Problem 5: Diesel Exhaust Fluid (DEF) System Issues

The 6.7L Power Stroke uses a Selective Catalytic Reduction (SCR) system that requires Diesel Exhaust Fluid. The DEF heater, DEF pump, and NOx sensors can all fail, especially on trucks that live in cold climates where the DEF can freeze. A failed DEF system will put the truck into a limp mode that limits speed to around 5 mph until the issue is resolved.

This is a known issue across all modern diesel trucks, not just Ford. But it is worth checking the DEF system health during any pre-purchase inspection.

Year by Year Breakdown

What to Check Before You Buy Any 6.7L Power Stroke

Should You Still Buy a 6.7 Power Stroke?

Absolutely. Despite these known issues, the 6.7L Power Stroke is still one of the best diesel engines available in a used truck. The problems listed here are well-documented, which means they are also well-understood and preventable. A truck that has been properly maintained, has a clean inspection history, and has had the CP4 protection kit installed is an excellent long-term investment.

The key is buying from a dealer who actually inspects what they sell.