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Ford 6.4L Powerstroke Diesel

The Ford V8 6.4L Powerstroke diesel was part of the Ford Powerstroke diesel engine family produced through a manufacturing partnership between Navistar International and Ford Motor Company formed more than 30 years ago.

The 6.4L V8 Powerstroke diesel engine was launched in 2008 for Ford Super Duty trucks (F-250, F-350, and F-450) and F-Series chassis cabs. Ending in 2010, the diesel engine had a short lifespan lasting only two years, and it was the last Power Stroke diesel engine made by the partnership.

This 6.4L Powerstroke diesel engine is a part of our Diesel Engine Guide series to help with buying a school bus for sale.

This article will dive further into the 6.4L Power Stroke diesel engine including:

6.4L Powerstroke Diesel Engine Overview

Built during an era of clean air regulation, the 6.4L Power Stroke diesel engine featured a common-rail injection system, turbocharger, and other components for reduced emissions and increased horsepower. At its base, the diesel engine had cast-iron blocks, a cast-iron bedplate, and cast-iron cylinder heads in an overhead valve design.

Most of the diesel engine’s problems stemmed from the overall design, as well as the new emissions equipment. Mechanics report that the diesel engine suffered from cracked pistons, leaky radiators, diesel particulate filter (DPF) clogging, and emissions equipment failures. 

Ford ended the partnership when replacing the problematic Navistar International 6.4L Power Stroke diesel engine with its own 6.7L engine for the 2011 model year Ford Super Duty trucks. Ford was able to shed losses from warranties/recalls on the Navistar International 6.4L and (predecessor) 6.0L Power Stroke engines and gain a competitive edge in the growing diesel segment by designing, engineering, and manufacturing its own diesel engine.

6.4L Powerstroke Engine Specs

Engine variationsProduction YearsHorsepowerTorque
Ford 6.4L V8 Power Stroke diesel engine2008 to 2010
Ford F-Series Super Duty trucks (F-250, F-350, F-450) and Ford F-Series chassis cab
350 hp @ 3000 RPM650 lb-ft @ 2000 RPM

6.4L Powerstroke Transmissions

The 6.4L V8 Power Stroke diesel engine was paired with either a Ford 5-speed automatic TorqShift transmission or a 6-speed manual transmission.

Towing with a 6.4L Powerstroke

Typically, the 6.4L V8 Power Stroke diesel engine allows Ford Super Duty trucks to tow a maximum of 16,000 pounds (F-450) or a minimum of 12,500 (F-150).

6.4L Power Stroke Engine Life Expectancy

Ford guaranteed the 6.4L V8 Power Stroke engine with a 150,000-mile warranty. Mechanics report that if properly maintained, the 6.4L V8 Power Stroke diesel engine could run for 375,000 before requiring a major repair or rebuild. However, many of the diesel engines suffered from issues before reaching the 200,000-mile mark.

6.4L Powerstroke Engine Maintenance Requirements

While there are several common problems with the 6.4L Power Stroke diesel engine, investing in high-end aftermarket parts and proper maintenance can improve reliability and engine lifespans.

6.4L Power Stroke Oil Capacity: 14 quarts

Engine variationsNormal conditions
6.4L V8 Power Stroke diesel engineOil capacity: 14 quarts
Engine oil & air filter: 10,000 miles/6 months
Severe use: 5,000 miles/3 months
Fuel filter: 10,000 miles
Engine coolant: 100,000 miles/6 years, then 50,000 miles/3 years
Transmission fluid & filter: 100,000 miles

Common 6.4L Powerstroke Engine Problems

These are some common issues with the Ford 6.4L Power Stroke diesel engine:

  • Cracked pistons – Mechanics report this issue occurs in higher mileage engines, especially after the 200,000-mileage point. The cracks first develop in the fuel bowl of the piston, and they can lengthen across the entire piston. Symptoms include excessive smoke, power loss, misfires and loss of compression.
  • Diesel particulate filter (DPF) clogging – The 6.4L Power Stroke diesel engine is the first Ford truck engine to use a diesel particulate filter. They are meant to capture particulates before they exit the exhaust to reduce emissions. Clogging symptoms include power loss, long cranks, and fault codes. Frequent maintenance and filter cleaning can prevent the issue.
  • Fuel in oil – Another common problem associated with the diesel particulate filter is fuel getting into the engine’s oil system. During regeneration, diesel is injected near the end of the engine’s exhaust stroke and mixes with gases to burn hydrocarbons in the filter. Residual fuel in the oil can result in severe internal engine damage. 
  • High-pressure fuel pump (HPFP) issues – Chafed wires in the HPFP cover gasket are common on the 2008 model year diesel engines. The unprotected wires rub on the pump and eventually wear a hole through the sheath, causing the bare wire to touch the block. This grounds-out the volume control circuit. It also causes no-starts. 
  • Oil cooler issues – Oil coolers are prone to clogging. It uses coolant to cool the oil, and those passages may become blocked over time. When this happens, oil temperatures may rise higher than normal and cause more failures.
  • Oil dilution – Fuel slips past the piston rings and accumulates in the crankcase. It’s common in DPF-equipped trucks that see more regeneration cycles. The more diluted your engine oil is with diesel fuel; the less lubrication reaches bearings and bottom-end components.
  • Poor fuel mileage – The 6.4L Power Stroke diesel engine suffers from poor fuel mileage, due to the diesel particulate filter’s need to burn off fuel at high temperatures for cleaner emissions.
  • Radiator cracks and leaks – This issue is more common in this Power Stroke diesel engine version. Engine vibration and weak bonding contributes to radiator cracks that leak coolant. If too much coolant is lost, the engine can rapidly overheat and fail. Seek immediate help when detecting visible leaks, overheating or steam from the engine bay.
  • Water in fuel – Fuel coagulation occurs in the collection bowl. The reaction between water and fuel forms a white, greasy substance, and the buildup blocks the drain valve ports. As the water collection system weakens, water eventually passes on to the fuel system and leads to rusting. Regular fuel filter changes can help prevent damage from this issue.
  • White and gray smoke – The hot-side intercooler book is known to hold moisture and cause white exhaust smoke intermittently, and in wet weather. White and gray smoke are most common in engines that fail to reach full operating temperature when on short trips. Overtime, condensation builds up on the hot-side boot.

6.4L Powerstroke vs. 6.0L Powerstroke

With all its issues, the 6.4L Power Stroke diesel engine followed the even more problematic 6.0L Powerstroke diesel engine. The Navistar International 6.0L Power Stroke diesel engine also was designed in response to increased emissions regulations. Ford Motor Company and Navistar International launched both engines for Ford Super Duty trucks, vans, and sport utility vehicles. 

As part of Navistar International’s VT diesel engine family, the 6.0L Power Stroke diesel engine had the same basic structure as the Navistar International VT365 but different components to meet emissions requirements, reduce turbo lag, and create better throttle response in Ford Super Duty trucks. The 6.0L Power Stroke engine featured an exhaust gas recirculation (EGR) system, fuel injection system with hydraulically actuated electronically controlled unit injectors (HEUI), four-valve cylinder heads, and a quick-spooling variable geometry turbocharger. 

Many of the issues with the 6.0L Power Stroke diesel engine stemmed from the emissions systems and/or lack of maintenance. Common problems included EGR clogging and cooling problems, oil cooler failures, high-pressure oil system failures, numerous electrical issues, and head bolt and head gasket failures. The engine issues escalated over the years and led to high warranty repairs, buybacks, and civil lawsuits against Ford.

Ford eventually canceled the manufacturing partnership with Navistar International due to issues with both the 6.0L and 6.4L diesel engines’ extensive recalls and warranty costs.

Feature comparison6.4L Power Stroke diesel engine6.0L Power Stroke diesel engine
Production years2008 to 2010
Ford F-Series Super Duty trucks (F-250, F-350, F-450) and Ford F-Series chassis cab
2003 to 2007 Ford Super Duty Trucks
2003 to 2005 Ford Excursion SUV
2003 to 2012 Ford E-series vans & chassis cabs
Horsepower350 hp @ 3000 RPM  Low: 325 HP @ 3300 RPM High: 350 hp @ 2600 RPM
Torque650 lb-ft @ 2000 RPMLow: 560 lb-ft @ 2000 RPM
High: 570 lb-ft @ 2000 RPM  (2005 to 2007 models)

6.4L Powerstroke vs. GM 6.6L Duramax

General Motors and Isuzu formed a joint venture, called DMAX, to produce a family of 6.6L Duramax diesel V8 engines for Chevrolet and GMC trucks, beginning in the 2001 model year. Over the past two decades, the joint venture has produced six variants of the Duramax diesel engine, including the 6.6L L5P Duramax diesel engine still in production today.

The 6.4L Power Stroke and 6.6L Duramax diesel engines were in production at the same time between 2008 and 2010. They both had challenges with new emissions controls systems and components added for meeting air quality control regulation at the time. 

Ford ended the partnership when replacing the problematic Navistar International 6.4L Power Stroke diesel engine with its own 6.7L engine for the 2011 model year Ford Super Duty trucks. Ford was able to shed losses from warranties/recalls on the Navistar International 6.4L and (predecessor) 6.0L Power Stroke engines and gain a competitive edge in the growing diesel segment by designing, engineering, and manufacturing its own diesel engine.

General Motors addressed its Duramax diesel engines by improving issues over six variants for Chevrolet and GMC heavy-duty trucks. As the original Duramax model, the 6.6L LB7 Duramax diesel engine came to market in 2001, and it has become a popular choice in the aftermarket due to the lack of emissions controls parts often blamed for engine issues in later models. 

The second diesel engine model, called 6.6L LLY Duramax, debuted in 2004. It was nearly identical to its LB7 predecessor in its componentry and lacked modern-day emissions control parts. GM fixed injector problems found in the previous engine model, but this variant reportedly had issues with overheating when towing heavy loads or driving in hot temperatures. 

The third diesel engine model, called 6.6L LBZ Duramax, came to market in 2006 for mainly General Motors Express and Savanna vans. Mechanics view it as the best model in the Duramax diesel engine line because it lacked troublesome emissions control parts and included a new six-speed Allison transmission. Production ended in 2007 as stricter emissions regulation became effective.

The fourth diesel engine model, called 6.6L LMM Duramax, debuted in 2007 and was nearly the same as its LBZ Duramax predecessor. The difference was new emissions control parts to meet increased air quality regulation in the U.S. at the time. The engine was known for cracking problems with its pistons. Production ended in 2011.

The fifth diesel model, called the 6.6L LML Duramax, was introduced in 2011 with enhanced emissions controls to meet even stricter air quality regulations. The diesel engine also managed to reduce noise vibrations and increase horsepower/torque by increasing the fuel system pressure. However, those component changes contributed to an injection pump issue. Production ended in 2016.

The sixth model called the 6.6L L5P Duramax, launched in 2017 and still is in production today for Chevrolet Silverado HD and GMC Sierra HD trucks. It is considered the best post-emissions Duramax engine, as previous issues with the injection pump and emissions systems have largely been fixed. In 2020, an Allison 10-speed automatic transmission replaced the old Allison 6-speed automatic transmission.

Feature comparison6.4L Power Stroke diesel engineGM 6.6L Duramax diesel engine
Production years2008 to 2010
Ford F-Series Super Duty trucks (F-250, F-350, F-450) and Ford F-Series chassis cab
2001 to 2004 6.6L LB7 Duramax
2004 to 2005 6.6L LLY Duramax
2006 to 2007 6.6L LBZ Duramax
2007 to 2011 6.6L LMM Duramax
2011 to 2016 6.6L LML Duramax
2017 to present 6.6L L5P Duramax Chevrolet Express
GMC Savana
Chevrolet Silverado HD
Chevrolet Kodiak
GMC Sierra HD
GMC Topkick
Hummer H1 Alpha
Horsepower350 hp @ 3000 RPMLow: 300 hp @ 3100 RPM
High: 445 hp @ 2800 RPM
Torque650 lb-ft @ 2000 RPMLow: 520 lb-ft @ 1800 RPM
High: 910 lb-ft @ 1600 RPM
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