The 6.7 Powerstroke CP4: A Potential Time Bomb?

The Ford 6.7L Powerstroke diesel engine is a powerhouse, known for its durability and impressive towing capacity. However, a specific component, the CP4 high-pressure fuel pump, has become a source of concern for many owners.

What is the CP4 and Why Does it Fail?

The CP4 is a high-pressure pump that injects fuel into the engine's cylinders. Unfortunately, early iterations of the CP4 in 6.7 Powerstrokes (from 2011-2019) were prone to failure. There are several reasons for this:

  • Lack of Lubrication: The CP4 relies on clean diesel fuel for lubrication. Contaminated or low-quality fuel can lead to increased wear and tear.

  • Water Contamination: Water in the fuel system can damage the CP4 and lead to internal corrosion.

  • DEF Contamination: Accidentally filling your diesel tank with DEF (Diesel Exhaust Fluid) can be catastrophic for the CP4.

Signs of CP4 Failure:

If your CP4 is failing, you might experience some of these symptoms:

  • Hard Starts: The engine struggles to crank due to insufficient fuel pressure.

  • Loss of Power: The engine feels sluggish and lacks acceleration.

  • Rough Idle: The engine vibrates abnormally at idle.

  • Check Engine Light: The dreaded CEL can indicate a problem with the fuel system, potentially the CP4.

What to Do if You Suspect CP4 Failure:

If you experience any of the above symptoms, don't ignore them. Take your truck to a qualified diesel mechanic for diagnosis. Early detection can help prevent further damage and potentially save your engine from a costly rebuild.

Repair Options:

Unfortunately, a failing CP4 often requires replacement. There are a few options to consider:

  • OEM Replacement: Replacing the CP4 with a genuine Ford part offers peace of mind but can be expensive.

  • Aftermarket Pump: Upgraded, aftermarket CP4 pumps are available that address some of the shortcomings of the original design.

  • DCR Conversion Kit: Some opt to convert their entire fuel system to the S&S Diesel, DCR Injection Pump. Which gains better fuel flow over stock and prevents catastrophic pump failure.

Preventing CP4 Failure:

There are steps you can take to minimize the risk of CP4 failure:

  • Regular Maintenance: Stick to your recommended maintenance schedule, using high-quality diesel fuel and filters.

  • Fuel Additive: Using a fuel additive will provide lubrication for your CP4 injection pump.

  • Avoid DEF Contamination: Double-check before filling your tank!

The CP4 issue can be a major concern for 6.7 Powerstroke owners. By being aware of the potential problems, the signs of failure, and preventative measures, you can help ensure your diesel engine runs strong for miles to come.

Compound Diesel