6.4 Powerstroke Problems: A (Still Growing) List

The short-lived 6.4L Powerstroke was the main powerplant in the light-duty truck market upon its release, and it's still a beloved engine by many truck enthusiasts.

The 6.4 Powerstroke was a replacement and an improvement to the 6.0 Powerstroke. We consider the engine to be more reliable, but it still has problems.

Let's break those problems down and fix them so that your 6.4 Powerstroke can run like new.

6.4 Powerstroke Problems By Year

The 6.4L Powerstroke had issues upon its release, the same as any other engine, and by the time Ford received feedback from truck owners, it was time to move on to the 6.7L Powerstroke. Every model year "six-four" was left with quite a few problems that we're going to tackle and resolve.

2008 6.4 Powerstroke Problems

Many truck enthusiasts believe that the 2008 model year 6.4 Powerstroke isn't reliable at all. They claim that the trucks need major repairs or even entire rebuilds by the time they reach 100,000 miles. The issues that can, and do, occur on the 2008 model year aren't simply resolved. Poor fuel economy, failure-prone turbochargers, shuttering, and of course, the infamous 'ticking' problem that 6.4 Powerstroke owners are far too familiar with. 

2008 was the first model year 6.4 Powerstroke and you should expect problems if you own one. Take a look at the “6.4 Powerstroke common problems” section down below for deeper explanations and resolutions.

2009 6.4 Powerstroke Problems

The 2009 model year 6.4L Powerstrokes are much more desirable. They aren't perfect, but the problems that the previous model year suffers from aren't as common. These model years most often suffer from oil dilution (Changing the oil on time will make your 6.4 much more reliable), emissions equipment problems, and terrible fuel economy. 

2010 6.4 Powerstroke Problems

2010 was the last production year for the 6.4 Powerstroke, and it shouldn't come as a surprise that these models are the most reliable. However, they need to be very well maintained (changing the fuel filters, draining water separator, changing the oil), only then will they prove reliable. You might still have a few issues with the fragile fuel system and the EGR system.

6.4 Powerstroke Issues & Common Fixes

The problematic 6.4 Powerstroke's systems are complicated, and fixing the issues that surface will be a major hassle. From emissions equipment to the fuel system, let's explore the common 6.4 Powerstroke issues, and find the solutions.

6.4 Powerstroke DPF Delete Problems

The Problem: Delete problems generally come down to getting engine codes that they 'shouldn't be getting' or poor performance.

Recommended Fix: You will need to review everything done to delete the vehicle and ensure it was done correctly, and has a correct tune to support the delete.

Explanation: Many 6.4 Powerstroke owners swear that deleting the emissions equipment made their truck much more reliable. However, adding more power with a tuner to an already powerful truck without installing supporting mods beforehand is never a good idea. Typically issues crop up because the delete was not performed entirely, or the truck was run much too hard after deleting without supporting modifications to the fuel, cooling, and powertrain systems.

6.4 Powerstroke Fan Clutch Problems

The Problem: The fan clutch locks up and produces a loud noise. With a broken fan clutch, the engine runs hotter, and the a/c performance drops.

Recommended Fix: Replacing the fan clutch is the only solution.

Explanation: Thermostatic spring opens and closes the valve that controls the flow of viscous silicone fluid in the clutch assembly. - The colder the fluid, the slower the clutch fan. However, a bad clutch might not be the problem. You could also have a bad valve, a bad thermostatic spring, or a fluid leak.

Quick Tip: To diagnose a bad fan clutch, spin the fan as hard as you can while the engine is cold. If the fan rotates more than five times the clutch is most likely broken. 

6.4 Powerstroke Turbo Problems

The Problem: Loss of power most often combined with a horrendous hissing sound. In another case, the turbo won't engage at all.

Recommended Fix: Replacing the turbo is usually the best solution.

Explanation: The twin-turbo system on the 6.4 Powerstroke produces quite a lot of power, but it is expensive. You should first check the expansion joints in the exhaust manifold pipes for cracks and damages, as it is often a cause of severe lack of power. If the turbo system doesn't engage at all, it’s time for a replacement, which will cost you just shy of $1000.

6.4 Powerstroke Injector Problems

The Problem: Bad fuel injectors can cause loss of power, rough idle, fuel in the oil, or the engine won't start at all.

Recommended Fix: Replacing the fuel injectors is the only viable solution.

Explanation: Fuel injectors on most diesel trucks usually fail. Some might last a bit longer, but bad fuel injectors are an issue familiar to every diesel truck owner. Many of them blame the fuel injector failure problems on poor diesel fuel quality. However, the 6.4 Powerstroke injectors are more reliable than the injectors on other trucks. Keep in mind that driving with bad fuel injectors can damage engine parts and cause major problems.

6.4 Powerstroke High Pressure Fuel Pump Problems

The Problem: You will notice the P0088 code, also known as the "killer code". Your truck might or might not turn on.

Recommended Fix: Replacing the high-pressure fuel pump is the only solution and it will cost you anywhere from $1,000 to $1,500.

Explanation: The number one cause of high-pressure fuel pump failure is improper maintenance. As long as you follow the maintenance schedule recommended by Ford, you won't have any problems. Draining the water from the fuel should be done every 30 days, but it isn't a simple process, and most owners become negligent after a while. If the truck does turn on, driving will contaminate the entire fuel system which will cost you around $5000 to $7000 to fix.

6.4 Powerstroke EGR Delete Problems

The Problem: After deleting the EGR system a green wrench will come up on the display along with a few codes.

Recommended Fix: Purchase an OHM meter and check the resistance between the pins on the removed EGR valve. You should get a reading of around 4.7 Kohms. Purchase 1/2 Watt 4.7 Kohm resistors. Install the resistors in the wiring harness between the two pins on the EGR valve and the issue should be fixed.

Explanation: Certain tunes don't work with EGR delete, while others do. If you purchase a custom tune, this issue shouldn't occur.

6.4 Powerstroke Transmission Problems

The Problem: The transmission will shift flare (go into neutral for a couple of seconds in between gears), or the transmission won't engage at all.

Recommended Fix: Replacing the solenoids is the best solution, but if your transmission doesn't engage at all, you might need to replace/fill-up the fluid.

Explanation: The transmission on the 6.4 Powerstroke is reliable, and it can handle a bit more power. However, you might be leaking fluid, or you might have sticky solenoids. Driving without fixing the issue will cause the entire transmission to break down in the near future.

6.4 Powerstroke Idle Problems

The Problem: Rough idle is a symptom of many problems; high-pressure fuel pump failure, bad fuel injectors, EGR system problems, and quite a few more issues.

Recommended Fix: Before attempting to fix the issue, you should scan your truck for codes to get a better understanding of why it has a rough idle.

Explanation: Rough idle is usually caused by poor combustions or misfires. Your engine needs a regular stream of fuel to run, and it also needs good compression. Checking the fuel system and doing the compression test will get you closer to the solution. If your truck's been idling for a long time, there could be a problem with EGR valves and turbo clogging.

6.4 Powerstroke Fuel System Problems

The Problem: The 6.4 Powerstroke's fuel system is susceptible to failures due to poor fuel quality.

Recommended Fix: Draining the water from the water/fuel separator every 30 days will prevent the issue. Installing a fuel lift pump system is an alternative fix.

Explanation: The water-fuel separator gets clogged up over time if it isn't drained often. Quite a few 6.4 Powerstroke owners recommend draining the water every two weeks instead of every month. If the water and fuel mix, the mix can create sludge and cause the drain valve to stick shut. Failing to empty the water will cause it to enter the fuel system, resulting in corrosion.

6.4 Powerstroke Fuel Rail Pressure Sensor Problems

The Problem: You will notice a decrease in power, acceleration, and terrible fuel economy. Your truck will also have a hard time starting. A check engine light might or might not appear.

Recommended Fix: Replacing the fuel rail sensor is the only fix. You will save a few hundred dollars if you're able to replace the sensor yourself.

Explanation: A bad fuel rail sensor will send inaccurate signals to the computer. The engine won't be supplied with adequate fuel, or it might be receiving too much fuel. In each case, the disturbance in the air-fuel ratio will cause a decrease in power. You can drive with a bad fuel rail sensor, but you should avoid doing so.

6.4 Powerstroke Rocker Arm Problems

The Problem: Once you start the engine, you'll hear a ticking/clicking noise. Alongside the noise, you'll notice poor performance and a 'check engine' light. If you also experience stalling, the rocker arms need to be replaced as soon as possible.

Recommended Fix: Replacing the bad rocker arm is the recommended solution. Some 6.4 Powerstroke owners replace the rocker arms soon after 100,000 miles as a preventive measure.

Explanation: The rocker arm failure happens because of the DPF system. The oil gets diluted due to the constant fuel dumps necessary for cleaning out the DPF system. The diluted oil doesn't provide enough lubrication, causing the rocker arms to scrape, wear down quickly, and break.

6.4 Powerstroke Wastegate Problems

The Problem: A bad/struck wastegate will cause your truck to lose power. In worst cases, the turbo won't engage at all.

Recommended Fix: Replace the wastegate with a new one. Alternatively, if you're experienced, you can unstuck the wastegate yourself.

Explanation: The turbo wastegate closes to create a low-end boost. After the turbo reaches a certain amount of boost, the wastegate opens up. A malfunctioning wastegate will cause the turbo to slowly spool up. Driving with a bad turbo wastegate isn't that big of a deal, but you should expect poor performance.

Conclusion

The unreliable, problematic 6.4 Powerstroke has a lot of doubters. However, it also has many fans who attempt to make it bulletproof. If you’re looking for power, this powerplant is the way to go, but do keep in mind that it will have problems. Hopefully, we were able to provide the solutions to your 6.4 Powerstroke’s problems, and you were able to fix your truck with our help!