What Is Wrong With Ford 6.4 Diesel?

Engine vibration and sloppy bonding on the core-to-tank ends of the 6.4L Ford Power Stroke engine’s (plastic) radiator tanks are to blame for cracks and coolant leaks. Almost all of these power stations have this issue. Overheating can cause serious engine damage as a result of the problem. A leaking stock radiator can only be fixed by replacing it with one of numerous good aftermarket aluminum radiators. Before or after the stock piece breaks, adding a core-support brace is a useful preventative measure.

Is the Ford 6.4 diesel any good?

The 6.4 Power Stroke engine was only used in Ford vehicles for a few years. It’s also the last Ford diesel from International, as the 6.7 Powerstroke was designed and built in-house by Ford. From the factory, Ford 6.4 diesel engines produce 350 horsepower and 650 torque. For the time period in which the 6.4 Powerstroke was released, they were respectable numbers. Some consider the 6.4L to be a more reliable engine than Ford’s previous 6.0 diesel engine. No engine, however, is perfect, and this is no exception. We’ll go through a few typical issues with the 6.4 Power Stroke as well as overall reliability in this article.

What are the problems with 6.4 Powerstroke?

While the 6.4L Power Stroke’s production cycle was only a few years long, International’s final engine for the Ford Super Duty proved to be a light duty vehicle market leader during its time on the market. Although poor fuel economy is the most prevalent complaint among 6.4L Power Stroke owners, the engine does have several flaws that have appeared frequently enough to be classified as common. Regardless, the engine was thought to be a step forward from the 6.0L Power Stroke and had significantly better reliability.

While the 6.4L Power Stroke’s performance attributes are remarkable, its fuel efficiency is mediocre. The 6.4L Power Stroke was Ford’s first engine to use a diesel particulate filter (DPF), an emission control device that collects soot from the exhaust stream. The filter must be cleaned as particulate matter accumulates. The major cleaning method is active regeneration, which involves injecting raw gasoline into the exhaust stream to elevate exhaust gas temperatures high enough to burn off the debris in the DPF. The engine is not intrinsically inefficient, but the exhaust aftertreatment system consumes a large amount of fuel, which is the source of the 6.4L Power Stroke’s poor fuel economy. Fuel economy suffers as a result of more frequent regeneration cycles.

Because tampering with emission control equipment is unlawful, owners have limited options for modification. The frequency of regeneration is mostly determined by driving behaviors. Long highway drives are great for reducing filter loading and, as a result, the requirement for frequent regeneration cycles. Excessive idling and stop-and-go driving, on the other hand, will result in more frequent regeneration due to repeated soot loading in the filter.

Fuel is delivered into the exhaust stream during the active regeneration process via a post-injection approach, in which fuel is injected late in the exhaust stroke so that it can exit the cylinder in its raw (or comparatively raw) state. Unlike the “9th injector” concept, which employs a dedicated fuel injector installed in the exhaust system, this method causes fuel to adhere to the cylinder wall, where it is delivered into the crankcase.

Fuel dilution is a regular and serious issue in the 6.4L Power Stroke, because diesel fuel lacks the lubricating characteristics of engine oil. However, fuel dilution is common and expected in this system. Owners should examine the engine oil frequency and consider changing their oil more frequently than Ford recommends to avoid possible harm from excessive gasoline dilution. Many owners, regardless of driving patterns, adhere to Ford’s “Severe” maintenance schedule, which reduces oil changes by half. If you see that the oil level in your crankcase is rising, have it replaced right away.

Cylinder washing is a problem that is closely linked to engine oil fuel dilution. Fuel injected late in the exhaust stroke has a tendency to “wash” the cylinder, diluting the thin coating of protective engine oil lining the cylinder while the active regeneration process is in action. While this hasn’t been linked to a high percentage of engine problems, it’s definitely not ideal for the 6.4L Power Stroke’s longevity.

Leaking radiators are prevalent and more noticeable on early engines; however, the problem appears to have been rectified and eliminated in later production engines. Leaks are most likely at the radiator’s ends, where the crimps that hold the end tanks in place loosen over time. New radiators are less likely to suffer leaks than older models, yet replacing one can be costly.

The 6.4L Power Stroke’s fuel-water separator is prone to clogging, often without the owner’s knowledge. When water collects in the separator’s bowl, it mixes with diesel fuel and coagulates, resulting in a thick, grease-like sludge that can clog the drain valve. When this happens, the fuel water separator will not drain and will allow water to enter the upstream fuel system once it reaches maximum capacity. The high-pressure fuel system could be severely damaged as a result of this. To avoid these issues, owners should drain the fuel-water separator on a regular basis; draining at the same time as the fuel filter is replaced has proven insufficient for this design.

Given that this was Ford’s first DPF-equipped vehicle, it’s worth remembering that DPF clogging concerns plagued every manufacturer (including the Cummins-powered Ram and the Duramax-powered GMC/Chevrolet HD) from the start. When the regeneration mechanism malfunctions or fails to keep the filter clean as necessary, diesel particulate filters can become blocked. Only use ULSD gasoline and engine oil that satisfies CJ-4 low ash requirements to lessen the likelihood of DPF clogging difficulties. Other diesel fuels and engine oils are incompatible with the 6.4L Power Stroke, causing ash to build up in the DPF. This ash will not be burned away during the regeneration process, necessitating manual cleaning of the DPF.

Chafing of the wire harness for the high-pressure fuel pump (injection pump) affects trucks manufactured before August 20, 2007. After this date, the wire harness will have a protective weave installed, which will eliminate this issue. When the wires of this harness are exposed due to wiring chafing, they face the risk of shorting to the HPFP. Ford is well aware of the issue, and TSB 07-26-2 was created in response to the concerns. If this problem arises, the service bulletin recommends replacing the harness with component # 8C3Z-9G805-A.

Cracking of the expansion joints on the exhaust up-pipes is a very typical problem on the 6.4L Power Stroke. Due to constant vibration and heat cycles, accordion style expansion joints have a tendency to fail. A loud hissing noise will usually precede a loss of power when this happens.

Cavitation is a phenomena in which vacuum pockets form and then quickly evaporate. As a result of the vacuum pocket collapsing, the surrounding coolant column collides with the neighboring surface. The forces of the crashing coolant column are small, yet they occur frequently and at a high pace. Over time, this results in the formation of holes. While cavitation hasn’t been known to damage the 6.4L Power Stroke’s cylinder jackets, it has been known to wear holes in the front engine cover. The problem is solved by installing a SCA/DCA (supplemental coolant additive/diesel coolant additive) in the cooling system, keeping the SCA/DCA concentration constant over time, and flushing the cooling system on a regular basis, as per Ford’s guidelines.

The 6.4L Power Stroke’s engine oil cooler, like the 6.0L Power Stroke’s, is prone to clogging. This is primarily due to engine coolant breakdown, and concerns can be alleviated by performing regular cooling system maintenance or installing a coolant filter. A blocked oil cooler can illuminate the check engine light, signifying a related DTC, and in severe circumstances, the engine will derate as a safety mechanism.

The Ford safety recall 07S49 affects trucks manufactured before March 9, 2007, and it addresses concerns about blazing exhaust caused by high exhaust heat during regeneration on the 6.4L Power Stroke engine. By changing the regeneration schedule, the recall refreshes engine calibration and resolves this issue, as well as a number of other DPF/active regeneration-related issues. Although only a few trucks were damaged, a popular video on the internet depicting a 6.4L with flames shooting out of the exhaust made the problem seem much more serious. Many people believe the owner of the truck in the video tampered with it to make the flames appear. Owners should not be alarmed; the recall was minor, and all trucks have been upgraded with new calibration, which eliminates the problem permanently.

How long will a Ford 6.4 diesel last?

If you treat your truck well, you should be able to get over 200k miles out of it with proper maintenance and an acceptable right foot.

What powerstroke to avoid?

The 6.0L Powerstroke is a well-known engine. Because of the engine’s poor performance, Ford and Powerstroke’s parent company, Navistar, were involved in a lengthy court dispute. Ford said Navistar produced a faulty engine. Ford has ignored unsatisfactory test results for the 6.0L Powerstroke, which could have prevented post-production issues, according to evidence.

As the Powerstroke suffered catastrophic failures, expensive engine replacement warranty claims flooded in. The cab of the vehicle had to be removed for the majority of these repairs. Because to this engine, many owners have lost faith in the brand. A series of recalls affecting this notoriously problematic truck are listed by Consumer Reports.

Is the Ford 6.4 a good engine?

One such engine is the 6.4L Power Stroke V-8 diesel, which was introduced for Super Duty trucks in 2008 as a replacement for the problem-prone 6.0L. Yes, it’s a better engine up front than its predecessor (and when modified properly, it can be a performance beast).

What is Ford’s best diesel engine?

“The critical factors for any diesel engine surviving forever are robust, iron parts, conservative power, and low engine speed—and if a 7.3L has been carefully maintained its whole life, 400,000 to 500,000 miles is nearly certain.”

Can you fix a 6.4 Powerstroke?

Piston cracking is a common problem with the 6.4L Powerstroke. This is more common in higher-mileage engines, but it can happen in all-mileage 6.4 trucks. If left ignored, even more serious problems, such as melted injector tips, can arise.

Piston cracking is caused by poorly constructed, low-durability pistons. The fuel bowl on OEM pistons is where the cracks generally begin at the thin edge. The cracks usually grow and worsen after that. This crack can then spread throughout the piston.

Fixing 6.4L Powerstroke Piston Problems

Unfortunately, changing the pistons in your 6.4L Powerstroke engine is a highly costly repair that necessitates engine disassembly. The truck appears to be better after replacing the OEM pistons with MaxxForce pistons. Because the International MaxxForce 7 engine was designed for heavier-duty commercial vehicles, it was slightly better built. The pistons used in the MaxxForce 7 do not have the tiny lip that causes piston cracking, making them far more reliable than the 6.4l Powerstroke’s.

It’s Not All Bad

While the 6.4L Powerstroke may appear to be unworthy of the trouble, many people swear by and enjoy these trucks. Thanks to its dual sequential turbochargers and common rail fuel injection system, the 6.4L Powerstroke boasts remarkable performance characteristics. Over 500 horsepower can be easily attained at a low cost.

However, this proclivity for becoming powerful can lead to troubles in the future. Any engine’s lifespan is generally shortened when its performance is increased. It’s best to avoid making changes that boost performance to unsustainable levels. Regular, proper maintenance is also greatly recommended. If you treat this engine like the dependable 7.3L Powerstroke, it will have a very short lifespan.

For more information on how to maintain these trucks, see our Comprehensive 6.4L Powerstroke Maintenance Guide. It includes the parts, fluids, and filters you’ll need to keep your 6.4 on the road, as well as recommended maintenance intervals.

Who makes the most reliable diesel engine?

The 7.3L Powerstroke is still widely regarded as one of the most dependable diesel engines ever produced. With 500 pound-feet of torque and 235 horsepower, it offers enough power for most purposes. With an air-to-air intercooler, oil-based fuelling, and long-lasting internal hard parts, it was built to last. When properly maintained, the Super Duty from 1999 to 2003 may travel much beyond 500,000 miles. If you’re looking for a secondhand 7.3L Powerstroke, you can get a fair deal on one with 150,000 to 250,000 kilometers.