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Complete Guide On: Common 6.4 Powerstroke Problems (+Solutions)

While it is true that the Powerstroke 6.4 has several performance improvements over the 6.0 version, it is still far from a perfect engine.

If you drive a 2008-2010 Ford Superduty truck, you’re likely to run into some of the Powerstroke 6.4 issues sooner or later.

The good news is that, as these are frequent faults, we already have a lot of experience detecting the causes and implementing possible solutions.

Pay attention because we bring you the most common Powerstroke 6.4 problems plus effective solutions in the following guide.

To solve the different issues we highly recommend the review of best upgrades for 6.4 Powerstroke

What is a Powerstroke 6.4 Engine?

A classic of Ford’s truck series, the 6.4 is one of those potent engines that every car enthusiast knows about.

Available since 1994, it has been powering most of the Ford F-Series trucks, going through the Ford Excursion and Ford LCF, Ford Ranger, as well as the most popular Ford Super Duty.

Nowadays, this engine is not produced anymore due to its obsolete design and construction. Other engines like the PowerStroke V8 at 6.7L have been taking the market by storm.

What makes the PowerStroke 6.4 engine such an enticing piece? It’s always been one of the most potent.

Powering up such beasts of trucks, this engine won a lot of appraisal in its time. Having said that, it is not an immaculate engine in any way. Below, we’ll teach you why.

Common Problems with the Powerstroke 6.4

Many owners of the Powerstroke 6.4L claim that it is a poorly designed engine from the factory, which also has very poor fuel consumption.

A frequent complaint is the high repair and service parts costs compared to other engines in the Powerstroke family.

In general, the most common Powerstroke 6.4 problems that owners have to deal with are:

1. Oil dilution

Oil thinning is one of the most common problems with the Powerstroke 6.4L, and unfortunately, it can put a lot of wear and tear on engine components in the long run.

This is a serious problem because “diluted oil” is actually diesel fuel, a product of the active regeneration process.

Since diesel fuel is not a lubricant like oil, it builds upon the cylinder wall, causing some damage in the future.

Solution

Change the oil more often than the Ford manual suggests. Take a look at the dipstick every week, and if it exceeds the maximum capacity, don’t hesitate to change the oil and filter as soon as possible.

It is best to change the oil every 8,000 kilometers, always using high-quality products such as Motorcraft SAE 15W40 Diesel Engine Oil.

2. Low fuel consumption

The Powerstroke is not nearly the best engine in terms of fuel efficiency.

This low consumption is due to its diesel particulate filter, which uses diesel oil to carry out its active regeneration process.

During this process, raw fuel is inserted into the exhaust stream to increase the gases’ temperature and thus clean the DPF.

Solution

The simplest solution is to avoid interrupted and stop-and-go driving periods. However, we know that this is not feasible for city drivers.

In this case, it will be necessary to invest some money in an accessory that improves your fuel efficiency, such as an Air Dog II-4G 100 GPH Lift Pump System.

3. Diesel Particulate Filter (DPF) clogging

Another problem with the Powerstroke 6.4 engine is the clogged diesel particulate filter (DPF).

We must not forget that this was the first Powerstroke with a filter, so it would be expected that it would present flaws in the design.

When the active regeneration process does not clean the filter properly, it becomes clogged over time.

Solution

To prevent or prolong this clogging as long as possible, always use ULSD fuel and lubricating oil that meets CJ-4 low ash specifications.

If you suspect that your diesel particulate filter is already clogged, it is best to buy a new one, as cleaning it is very complicated.

4. Radiator leaks

Radiator leaks are a known problem with Powerstroke 6.4L engines, especially in those first introduced to the market.

Leakage can occur when the crimps on the ends of the radiator separate or loosen. Another clear sign of a leak is overheating due to coolant loss.

Solution

In this case, there is no other solution than to discard the radiator and buy a new one. A good choice is the Mishimoto 6.4L Powerstroke aluminum radiator because its ends are fully welded.

If your radiator still works but wants to prevent the crimps from loosening, the Mishimoto Radiator Top Support Bar will help it be more rigid and stable.

5. Oil cooler clogging

Among the Powerstroke 6.4L problems we frequently see is oil cooler clogging.

This problem occurs when coolant decomposition blocks the oil cooler outlets.

The most severe consequence of this blockage is that the engine slows down as a protective measure, causing 6.4L Powerstroke engine problems.

Solution

First, make sure if your oil cooler is not working correctly, measure the coolant and engine oil temperature.

If between the 2 values there is a difference of more than 14 degrees, there is a blockage, or it is about to occur.

Unfortunately, it is not possible to clean the oil cooler outlets. The solution is to replace your old cooler with a new OEM Ford compatible oil cooler.

If you wish, you can also purchase a coolant filtration system to extend the oil cooler’s life.

6. EGR System Failure

Speaking of coolants, another problem with the Powerstroke 6.4 is the failure of the EGR system.

This cooling system is intended to lower the exhaust gases’ temperature as they are transported through the EGR valve.

To accomplish this process, a coolant is used that, over time, can clog the EGR cooler (just like the oil cooler).

The main concern is that the Powerstroke 6.4 uses 2 EGR coolers, and both can clog.

Solution

If your EGR system is already clogged, you need to replace it with new coolants. Fortunately, several options are more durable and reliable than the Powerstroke 6.4L’s EGR system.

If you want to prevent clogged EGR coolers, it’s best to invest in coolant filters, such as the Mishimoto Coolant Filtration System.

7. Cylinder Flushing

The cylinders of the Powerstroke 6.4 engine can be affected by the active regeneration process.

When fuel is introduced late in the exhaust stroke, it can remove the engine oil’s delicate layer that coats and protects the cylinder.

Consequently, the cylinder fails to retain the lubricant, leading to breakdowns and progressive deterioration in the cylinder.

Solution

The best way to fix a cylinder that’s flushing is to replace it. When this happens, it is a prevalent sign the cylinder is about to stop working.

Doing a temporary repair may be almost useless, as it is likely to start failing again very soon. We recommend getting a new one and replacing it yourself.

But if you’re willing to spend a bit of money on the job, a mechanic may charge you anywhere from fifty bucks up to a hundred for the job. If you’re lucky, you may find it a lot cheaper (but it’s rare).

8. Cracks in pistons and Exhaust Pipes

In higher mileage Powerstroke 6.4 engines, it is very common to find cracks in pistons and risers.

Piston cracking is nothing more than the result of a bad design, which sooner or later will generate longer and longer cracks.

Something similar happens with exhaust pipes, where cracks often appear in the expansion joints, causing a significant loss of power, excessive soot, loud whistling under the hood, among other symptoms.

Solution

For exhaust pipes, the only solution is to replace them with new ones. Fortunately, there is a wide variety of options in the aftermarket, with better quality and lifetime warranty.

In the case of the pistons, unfortunately, the solution is not very encouraging, as you will have to disassemble the engine so that you can change the pistons.

9. Cavitation of the Front Cover

In the list of problems of the Powerstroke 6.4, we always find the front cover cavitation. Cavitation is a phenomenon that forms vacuum pockets that vanish very quickly.

As a consequence of this phenomenon, the front cover leaks, causing coolant to seep into the crankcase and deteriorate the holes in the front cover of the engine.

Solution

If you already have a leaking front cover, you will have no choice but to replace it, which is quite costly.

To prevent cavitation, make sure you buy a quality coolant and have a proper SCA/DCA coolant additive.

10. High-pressure fuel pump cable chafing

High-pressure fuel pump cable chafing is one of the common problems of the Powerstroke 6.4L, mainly on those manufactured before August 2007.

This chafing is caused by vibration, which over time, can cause the harness wiring to become exposed and short out to the HPFP.

Solution

Purchase Ford replacement harness Part # 8C3Z-9G805-B. This harness comes with a protective cover that will prevent the wiring from being exposed by vibration.

11. Fuel water separator problems.

To add another flaw to the Powerstroke 6.4 group of problems, we have the fuel-water separator, which can clog if it is not drained as often as it needs to be.

If water and fuel mix, they create a sludge that causes the drain valve to clog. If water enters the truck’s fuel system, it oxidizes it and reduces fuel quality.

Solution

To avoid this problem, the best thing you can do is drain the fuel-water separator as often as possible.

If the problem has already appeared and you want to improve fuel quality, purchase a lift pump system, such as the Air Dog II-4G 100 GPH.

If you want to know more about common problems with the Powerstroke 6.4, we recommend you to watch the following YouTube videos:

Common Ford Powerstroke 6.4 Issues and Problems.

Frequently Asked Questions (FAQs)

Why does the Powerstroke 6.4 have so many problems?

Most of the problems with this engine are due to its design and new emissions to meet stringent EPA regulations.

Does this mean that the Powerstroke 6.4 is inefficient?

Not exactly. While it is true that the Powerstroke 6.4L has many common problems, in most cases, they are easily prevented with constant maintenance and upgrades.

What kind of maintenance does the Powerstroke 6.4 require?

In general, it is best to perform a general check-up of your truck when it reaches 8,000 kilometers (5,000 miles).

It is essential to drain the fuel-water separator at least every 2 weeks and, if possible, to buy accessories and compatible parts that significantly improve the engine’s life.

Unfortunately, the maintenance of the Powerstroke 6.4 is quite expensive, as many of the repairs require lifting the cabin.

What components can you buy to improve the performance and life of your Powerstroke 6.4?

Since most of the Powerstroke 6.4 issues are due to its factory components, the best solution to extend its life is to buy the best components available on the market.

If you want to avoid headaches in the future, be sure to invest in coolant filtration systems, radiators, exhaust pipes, and a fuel lift pump system.

Is the Powerstroke 6.4L better than the 6.0L?

Not really. The Powerstroke 6.4, while an engine with potent performance capabilities, has proven unreliable and has an abysmal fuel economy.

Besides, problems with cracked radiators and exhaust pipes contribute to its poor reputation.

Conclusion

So, did you learn a thing or two about the common Powerstroke 6.4 problems? We hope so!

There are many things to know about this engine that it would be a pity you get a truck with one and don’t know how to fix it. Even worse, not knowing what could be its problem when it fails.

Follow our advice and recommendations above and get rid of any problem you may be experiencing with that 6.4L Powerstroke.

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