Power Stroke, also known as Powerstroke, is a family of diesel engines that were produced by Navistar International from 1994 until 2010, and by Ford Motor Company since 2011. Along with its use in Navistar's medium-duty trucks and in the Ford F-Series (including Ford Super Duty trucks), applications include the Ford E-Series, Ford Excursion, and Ford LCF commercial truck, and South American production of the Ford Ranger.
From 1994 until 2010, Power Stroke engines sold by Ford were re-branded versions of Navistar International medium-duty truck engines. Since the 2011 introduction of the 6.7 L Power Stroke V8, Ford has designed and produced its own diesel engines. The Power Stroke engine range has been marketed against large-block V8 (and V10) gasoline engines along with the General Motors Duramax V8 and the Dodge Cummins B-Series inline six.
Engine family list +NominalFamilyConfigurationTurbochargerProduction7.3Navistar T444E 16-valve V8Single, wastegated1994–20036.0Navistar VT365 32-valve V8Single, variable-geometry2003–2007 (Super Duty) 2003–2010 (E-Series)6.4Navistar MaxxForce 7 32-valve V8Compound, variable-geometry2008–2010 6.7Ford Scorpion 32-valve V8Single, variable-geometry (Twin-scroll Turbocharger)2011–present3.2Ford Duratorq (Puma) 20-valve I5Single, variable-geometry2015–present3.0Ford Power Stroke 24-valve V6Single, variable-geometry2018–2021
7.3 Power Stroke
The first engine to bear the Power Stroke name, the 7.3 L Power Stroke V8is the Ford version of the Navistar T444E turbo-diesel V8. Introduced in 1994 as the replacement for the 7.3 L IDI V8, the Power Stroke/T444E is a completely new design, with only its bore and stroke dimensions common with its predecessor (resulting in its identical displacement). In line with the IDI diesel, the Power Stroke was offered in three-quarter-ton and larger versions of the Ford F-Series and Econoline product ranges.
The Power Stroke is an electronically controlled, direct injection engine with a bore and stroke creating a displacement of . It has a 17.5:1 compression ratio, and a dry weight of approximately . This engine produces up to and of torque in automatic transmission trucks from the last years of production, and and of torque in manual transmission trucks. The oil pan holds while the top end (due to the HPOP)High Pressure Oil Pump, which creates oil pressure to fire the fuel injectors. The HPOP is responsible for creating injection pressures in a range of 450 to 3,000 psi on 7.3L engines, and 450 to 3,600 psi on 6.0L Power Strokes. The HPOP is controlled by the IPR (Injection pressure regulator) which in turn is controlled by the PCM. holds an additional , making for a total of of oil contained within the engine.
The 1994.5 to 1996/97 DI Power Stroke has "single shot" HEUI (hydraulically actuated electronic unit injection) fuel injectors which were AA code injectors unless from California where as they received AB code injectors. It ran a high pressure oil pump (HPOP) to create the necessary oil pressure to fire the fuel injectors. This generation of Power Stroke utilizes an HPOP with a 15° swash plate angle. The 1995-1997 trucks use a two-stage cam-driven fuel pump, whereas the 1999-2003 trucks use a frame rail mounted electric fuel pump. The 1999–2003 trucks also had a deadhead fuel system and a "long lead" injector in cyl. number 8 due to lower fuel pressures with the deadhead design (AE code injector). The California trucks from 1996 and 1997 have a split-shot fuel injectors; other trucks did not get split-shot injectors until 1999. Single-shot injectors only inject one charge of fuel per cycle, whereas the split-shot injector releases a preliminary light load before the main charge to initiate combustion in a more damped manner. This "pre-injection" helps reduce the sharp combustion 'knock' as well as lower NOx emissions by creating a more complete burn.
1994.5–1997 engines utilize a single turbocharger, non-wastegated, with a turbine housing size of 1.15 A/R. For 1999, an air-to-air intercooler was added to cool the charged air from the turbo for increased air density. With the new cooler, denser air would increase the horsepower potential of the engine, while also reducing exhaust gas temperatures (EGT). The turbine housing was changed to a .84 A/R and a wastegate was added halfway through the 1999 model year. The 1999 engine also received injectors, up from in the early model engine. With the larger injectors, the HPOP capability was increased by utilizing a 17° swash plate angle to meet the requirements of the new, higher flowing injectors.
The engine used forged connecting rods until powdered metal rods were introduced for early 2002 models. Serial numbers can be seen with the aid of a borescope to confirm the changeover between the 2001 and 2002 model years. These new connecting rods sufficed in an unmodified engine, but would become a potentially catastrophic failure point if aftermarket tuning pushed the engine above . Early models did not use any form of exhaust aftertreatment, such as a catalytic converter, as emissions were not enforced on diesel engines; however, by mid-year 2002, Ford began installing catalytic converters as part of the OEM exhaust as part of the Tier 1–3 standards.
Common issues
Despite being regarded as one of the most reliable diesel engines ever put in a light-duty truck,dead link the engine had its own issues. A common failure point was the camshaft position sensor (CPS). The failure of this sensor would cause a no-start condition or a stall while running. The easiest way to diagnose a failed CPS is through movement of the tachometer when cranking. If the tachometer does not move, the CPS is most likely bad. The fuel filter/water separator also tends to be a minor failure point across the trucks. The aluminum filter housing can crack, causing fuel leaks. The heating element contained in the filter housing also can short out, blowing a fuse and causing a no start condition. The turbocharger up-pipes are a large failure point, with the pipes leaking from many different points but mainly from the joints. Leaking of the up-pipes causes the engine to lose boost and cause exhaust gas temperatures to increase. The EBPV exhaust back-pressure valve (EBPV) was also prone to failure; it could close when cold and get stuck on causing a jet engine like noise coming from the exhaust.
Most of the issues that came out of these motors were due to poor electrical connections. The UVCH (under valve cover harness) was prone to losing contact with either glow plugs or injectors which caused rough starts or a misfire depending on the year. 1994–1997 engines have two connectors going into each bank, whereas 1999–2003 engines had one connector going into each bank; troubleshooting the harness was easier for the 1994–1997 engines.
The 7.3 L DI Power Stroke was in production until the first quarter of model year 2003, when it was replaced by the 6.0 L. Nearly 2 million 7.3 L DI Power Stroke engines were produced in International's Indianapolis plant.Ford's Power Stroke Diesel History Power Stroke Spotters' Guide
The 7.3 L DI Power Stroke engine is commonly referred to as one of the best engines that International produced.
6.0 Power Stroke
The Power Stroke was replaced by the beginning in the second quarter of the 2003 model year. The 6.0L Power Stroke, was used in Ford Super Duty trucks until the 2007 model year but lasted until 2009 in the Ford Econoline vans (model year 2010) and in the Ford Excursion SUVs until after the 2005 models when Ford discontinued Excursion production. The engine has a bore and stroke creating a displacement of . It utilizes a variable-geometry turbocharger and intercooler, producing and torque with an 18.0:1 compression ratio, with fuel cutoff at 4,200 rpm. Many 6.0 L Power Stroke engines experienced problems.
Key specifications Fuel injection system: Split-shot HEUI (hydraulically actuated electronically controlled unit injectors) Valve train: OHV 4-valves per cylinder, 32 valves total (16 intake valves, 16 exhaust valves) Turbo configuration: Single; variable vane geometry (VGT)
Common issues / – The sources of the main issues with the 6.0L were the in-block oil cooler, and the EGR cooler materials. The oil cooler is located in the valley of the engine block, underneath the cartridge oil filter set up. The sealed outer portion of the oil cooler is submerged in engine oil, with coolant flowing through the center passages. Over time, the coolant side of oil cooler would plug up with sediment. This would reduce the flow of coolant through the oil cooler and cause higher oil temperatures. This sediment would also reduce the flow of coolant through the EGR cooler resulting in premature failure due to thermal expansion fatiguing the heat exchanging core. The early EGR coolers (2003-2004.5) were also susceptible to premature failure.
– With the use of split-shot HEUI fuel injectors, high-pressure oil is required to pressurize the fuel injectors. The main high-pressure oil (HPO) system components are the high-pressure oil pump (HPOP), HPO manifolds, stand pipes, and branch tube. The HPOP is located in the engine valley at the rear of the engine block. Early build years (2003.5–04.5) are well known for premature HPOP failure. This is due to the poor quality materials used in manufacturing. The HPOP is pressurized by a rotating gear, meshed with a rear camshaft gear. The early model HPOP gears were known to be weak, and develop stress cracks in the teeth resulting in gear failure, thus causing a no start issue for the engine. Early models also had the ICP sensor located on the HPOP cover. The high amount of heat in this location, combined with the exposure to debris in the oil was known to cause ICP sensor failure also resulting in a no-start condition. This issue was addressed by Ford with the late-2004 engine update, bringing a new HPOP design, along with relocation of the ICP sensor to the passenger-side valve cover. The newly designed pump is not known for frequent failure, however a new issue arose with the update. In the late model engines, Ford also redesigned the HPO stand pipes and dummy plugs in the HPO manifold, using poor-quality O-rings. These O-rings were prone to failure causing a HPO leak, and eventually a no-start condition. Ford addressed this concern with updated Viton O-ring washers fixing the issue. With the new HPO system design also came a snap-to-connect (STC) fitting. Some models had the issue of the STC fitting's prongs breaking, causing the fitting to lose its sealing property and again, a no-start condition for the engine. Another frequent (but not always catastrophic) issue with the HPO system is the injection pressure regulator (IPR) screen. The IPR screen is located in the engine valley with the oil cooler. The material used was susceptible to failure and neglecting to replace the screen during an oil cooler replacement could lead to the debris being sent through the HPOP causing complete failure. If the HPOP does not fail, another common failure point is the IPR that, if contaminated by debris, will not be able to seal completely and will then "bleed off" oil pressure causing a no-start condition.