Ford Power Stroke engine

Power Stroke is a line of diesel engines found in Ford diesel trucks, Ford Excursion SUVs, Ford Econoline vans, Ford LCF commercial vehicles and the Brazilian Ford Ranger. The V8 engines were produced by Navistar International Corp. until 2010 when Ford decided to build their diesel engine completely in-house. The Power Stroke engines compete primarily in the United States full-size pickup truck market with the Duramax V8 from General Motors/Isuzu and the B Series straight-six from Cummins.

7.3 Power Stroke

The 7.3L Power Stroke diesel was made available for 1994.5 models in Ford Econoline vans, and Ford heavy duty pickups. It effectively replaced the 7.3 IDI with which it shares nothing other than displacement size.

The Power Stroke is an electronically controlled, direct injection engine with a 4.11 in (104 mm) bore and 4.18 in (106 mm) stroke creating a displacement of 444 cu in (7.3 L). It has a 17.5:1 compression ratio, and a dry weight of approximately 920 lb (420 kg). This engine produces up to 250 hp (190 kW) and 505 lb·ft (685 N·m) of torque in automatic-transmission trucks from the last years of production, and 275 hp (205 kW) and 525 lb·ft (712 N·m) of torque in manual-transmission trucks. The oil capacity is 15 quarts (17.03 liters). The oil pan holds 12 quarts (14.20 liters) while the top end holds an additional 3 quarts (2.84 liters).

The 1994.5 to 1996/97 DI Power stroke has "single shot" HEUI (hydraulically actuated electronic unit injection) fuel injectors and 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 cam-driven fuel pump, whereas the 1999-2003 trucks use a frame rail mounted electric fuel pump. The California trucks from 1996 and 1997 have 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 controlled injection helps reduce the sharp combustion 'knock'.

It utilizes a single turbocharger with a turbine housing size of 1.15 A/R. In 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). Eventually, the turbine housing was changed to a .84 A/R and a wastegate was added. With larger injectors, the HPOP output was increased by utilizing a 17° swash plate angle to meet the requirements of the new, higher flowing injectors.

The 7.3 L DI Power Stroke was in production until the second quarter of model year 2003 when it was replaced by the 6.0L because of its inability to meet newer emission requirements. Nearly 2 million 7.3s were produced from International's Indianapolis plant.^[2]

The 7.3 L DI Power Stroke engine is commonly referred to as one of the best engines that International produced.^[3]

6.0 Power Stroke

The 7.3 L (444 CID) Power Stroke was replaced by the 6.0 L (365 CID) 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 3.74 in (95 mm) bore and 4.13 in (105 mm) stroke creating a displacement of 365 cu in (6.0 L) or 5,954 cc. It utilizes a variable geometry turbocharger and intercooler, producing 325 hp (242 kW) and 570 lb·ft (773 N·m) torque with an 18:1 compression ratio, with fuel cutoff at 4,200 rpm. Many of the 6.0 L Power Stroke engines experienced problems,^[4]

Key specifications

• Fuel injection system: Split-shot HEUI (hydraulic electronic 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

Oil Cooler/EGR Cooler - 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 oil cooler will develop small cracks in the aluminum tubes from the constant heating and cooling of the engine. This situation usually results in oil pushing it's way into the cooling system. The sludge created from the mixture of oil and coolant creates a high pressure environment in the EGR cooler (due to the viscosity change in the coolant), leading to cracking of the EGR cooler's coolant passages. Once the EGR cooler cracks, it begins to leak coolant into the intake system and is then routed into the engine's cylinders to be burnt. The burning of coolant in the cylinders then causes a steam buildup, thus increasing cylinder pressures and the stretching of the head bolts; which leads to head gasket failure. The early EGR coolers (2003-2004.5) were also susceptible to pre-mature failure without oil cooler issues, also resulting in head gasket failure.

High Pressure Oil System - 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; 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 pre-mature 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 Connet (STC) fitting. Some models had issue with the prongs of the STC fitting breaking causing the fitting to lose it's 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.

Head Gaskets - Ford/International used four Torque to Yield (TTY) cylinder head bolts per cylinder for the 6.0s and 6.4s. TTY bolts offer some of the most precise clamping force available, but can be problematic. In certain situations (Oil cooler/EGR cooler failure, high boost/load levels brought on by improper use of aftermarket programmers) TTY bolts can be stretched beyond their torque mark by increased cylinder pressures. This has never been addressed by Ford due to the fact that other malfunctions or abuse must occur to stretch the bolts. Some in the aftermarket will replace the factory bolts with head studs in an attempt to protect the head gaskets from future failure. If this is done without addressing the underlying issue, the head gaskets may fail again bringing along a cracked or warped cylinder head. In contrast, the Powerstroke 7.3s and 6.7s have 6 head bolts per cylinder while the IDI 7.3s and 6.9s have five. ^[5]

Electrical and fuel

Numerous PCM recalibrations, fuel injector stiction along with several other driveability and quality control problems have plagued the 6.0. The FICM (fuel injection control module) has been a problem, where low voltage in the vehicle's electrical system due to failing batteries or a low-output alternator can cause damage to the FICM. In addition, the placement of the FICM on top of the engine subjects it to varying and extreme temperatures and vibrations causing solder joints and components to fail in early build models; mostly in the power supply itself. The FICM multiplies the voltage in the fuel injector circuit from 12 to 48-50 volts to fire the injectors. Low voltage can eventually cause damage to the fuel injectors.

6.4 Power Stroke

The 6.4L Power Stroke was introduced for the 2008 model year. The 6.4L Power Stroke was the first engine introduced to the light truck market that utilized dual turbochargers from the factory. This was the first Power Stroke to use a diesel particulate filter (DPF) in order to nearly eliminate particulate emissions. The new DPS and active regeneration system greatly hindered the engine's fuel economy capability, though the engine proved to be comparatively strong and reliable. The engine was ultimately retired after the 2010 model year, as Ford replaced it with its own in-house built 6.7L Power Stroke.

The engine has a 3.87 in (98 mm) bore and 4.13 in (105 mm) stroke, resulting in a total calculated displacement of 387 cu in (6.3 L) (6,333 cc). Despite having to meet emission regulations, the engine was able to increase horsepower ratings to 350 hp (261 kW) and torque to 650 lb·ft (881 N·m) at the flywheel. Horsepower and torque are achieved at 3,000 rpm and 2,000 rpm respectively. It also features a compound VGT turbo system. Air enters the low-pressure turbo (the smaller of the two) and is fed into the high-pressure turbo (the larger of the two), then is directed into the engine or intercooler. This system is designed to result in reduced turbo lag when accelerating from a stop. The series-turbo system is set up to provide a better throttle response while in motion to give a power flow more like a naturally aspirated engine. The 6.4 L also has a DPF and dual EGR coolers which are capable of reducing exhaust gas temps by up to 1,000 degrees before they reach the EGR valve and mix with the intake charge. The DPF traps soot and particulates from the exhaust and virtually eliminates the black smoke that most diesel engines expel upon acceleration. The engine computer is programmed to periodically inject extra fuel in the exhaust stroke of the engine (known as a "regeneration" in the F-Series) to burn off soot that accumulates in the DPF. This engine is designed to only run on ultra low sulfur diesel (ULSD) fuel which has no more than 15 ppm sulfur content; using regular diesel fuel results in emission equipment malfunctions and violates manufacturer warranties.

The 6.4L has had one recall (safety product recall 07S49 was released on March 23, 2007) that addresses the potential for flames to come from the tailpipe of the truck. This problem arises from the DPF which is part of the diesel after-treatment system. A PCM recalibration was released to eliminate the possibility of excessive exhaust temperatures combined with certain rare conditions resulting from what is becoming known as a "thermal event".

Key specifications

• Fuel injection system: High pressure commonrail
• Valve train: OHV 4-valve
• Compound VGT turbo
• DPF
• Advanced multi-shot piezoelectric fuel injection control

6.7 Power Stroke

Emissions controls include exhaust gas recirculation, Denoxtronic-based selective catalytic reduction (SCR) from Bosch, and a DPF. Output was originally 390 hp (291 kW) and 735 lb·ft (997 N·m).^[6] but shortly after production started, Ford announced that they made an update to the 6.7L diesel. The new engine control software makes the engine capable of 400 hp (298 kW) at 2,800 rpm and 800 lb·ft (1,085 N·m) at 1,600 rpm while achieving better fuel economy and without any physical changes to the engine. ^[7] The 2015 engines are rated at 440 horsepower (330 kW) and 860 lb·ft (1,166 N·m).^[8] Ford claims the bump in horsepower is from a new turbo, new injector nozzles and exhaust improvements.

Key specifications

• DPF
• Valve train: OHV 4-valve
• Turbo configuration: 'GT32 SST (single sequential turbocharger)' --single 64mm turbine and dual-sided compressor
• Fuel injection system: High-pressure common-rail, Bosch CP4 injection pump, piezo electric injectors

2015—2016^[9]

3.2 Power Stroke

The 3.2 L Power Stroke is an inline five-cylinder engine that debuted in the U.S.-spec Transit for model year 2015. The engine is a modified version of the Ford Duratorq 3.2 L diesel engine that has been adapted to meet emissions in the United States. To aid in economy, emissions, and reduce NVH, it has a high pressure common rail fuel injection system and piezo injectors that can spray up to five different injections per compression event. It has a water cooled EGR system to reduce the temperature of the exhaust gas before being recirculated through the intake. A unique feature to the emissions system is that the diesel oxidation catalyst (DOC) and the DPF have been combined into one singular unit as opposed to the traditional two separate units. Exhaust treatment continues with SCR which is done by the injection of diesel exhaust fluid in the exhaust to reduce NOx. The engine features a variable geometry turbo which allows for intake air flow tuning on the fly to increase power and fuel economy. The engine also features a variable-flow oil pump to avoid wasting mechanical energy pumping excessive amounts of oil. It has cast aluminum, low friction pistons with oil squirters to keep them cool during heavy-load conditions, a die cast aluminum cam carrier to stiffen up the valve train and reduce NVH, and to increase low end durability, the crankshaft is cast iron and the connecting rods are forged. The block itself is an extra rigid, gray cast iron with a closed deck.^[11] The power figures for the 3.2 L Power Stroke are 185 hp at 3,000 rpm and 350 lb-ft at 1,500-2,750 rpm. The Euro Duratorq 3.2 makes 197 HP and 350 ft-lb of torque.

Key specifications

• Fuel injection system: High pressure commonrail
• Valve train: DOHC 4-valve
• Turbo configuration: Single variable geometry turbo
• Combined diesel particulate filter and diesel oxidation catalyst
• Urea injected selective catalytic reduction

3.0 Power Stroke

The 3.0 liter Power Stroke turbo-diesel is set to be introduced in the new 2018 Ford F-150 as a light duty engine to compete with the Ram 1500 EcoDiesel V6. The engine is expected to produce close to 255 hp (190 kW) while maintaining fuel efficiency.

Applications

The Power Stroke engine has been used in the following applications.

Ford E-Series (full-size vans)

• 1995–2003 7.3 L
• 2004–2010 6.0 L

Ford F-Series (full-size pickup trucks)

• Mid-1994–Mid-2003 7.3 L^[12]
• Mid-2003–2007 6.0 L
• 2008–2010 6.4 L
• 2011–present 6.7 L
• 2018– 3.0 L (F-150 only)

LCF (low cab forward)

• 2005–2010 4.5 L

Ford Transit

• 2015–present 3.2 L

Other engines with the Power Stroke name

• In South American models, the Ford Ranger 2001 up to 2012 use a Power Stroke engine in their diesel versions. A 2.8L diesel engine was developed by Navistar/International Engines from an inline-four Land Rover Defender diesel 2.5L engine, with 130 (waste gate) or 133 hp (VNT). A 3L common rail four valves per cylinder and 160 hp (waste gate turbo) became the electronic version of the Power Stroke. It has only the block and connect-rods in common with 2.8 L Power Stroke
• The above-detailed 3.2L Duratorq I5 is branded as Power Stroke in US-spec Ford Transit vans.

See also

• Ford engines
• Ford Modular engine

References

External links

• Powerstroke Diesel home page
• Navistar International
• Power Stroke Diesel Specs