Ford 6.7 Power Stroke Diesel Engine
The 6.7L Power Stroke is the first medium duty diesel designed and built by Ford. During design, Ford engineers codenamed this engine “Scorpion” due to the exhaust manifold and turbo being mounted in the engine’s “valley”. Ford Motor Company has done an amazing job with the 6.7 Liter Power Stroke engine, which has impressive performance, fuel economy, reliability, and longevity.
- 6.7 Power Stroke Specifications
- 6.7 Power Stroke Longevity and Reliability
- 6.7 Power Stroke Problems
The 6.7 liter engine initially had a unique single sequential turbocharger (SST), which features a dual compressor and single turbine setup affixed to a common shaft. The unit was replaced by a single Garrett GT37 variable geometry turbocharger (VGT) for the 2015 Power Stroke, increasing horsepower and torque in combination with additional upgrades. The SST returned for the completely revised 2017 Super Duty; torque reached an all time high at 925 lb-ft.
Unique to the 6.7 liter engine is the exhaust and intake manifold designs. As opposed to a tradition V engine, the intake and exhaust flows are reversed – the intake manifolds are located on the outer deck of the cylinder head and the exhaust manifolds exit directly into the engine valley where the turbocharger is mounted. The unique exhaust flow design is said to increase thermal efficiency of the turbocharger.
6.7 Liter Engine Emissions System Overview
• Exhaust gas recirculation (EGR). A unique feature of the 6.7 liter engine is that EGR flow is controlled by the EGR valve prior to entering the EGR cooler, as opposed to cooling the exhaust gases before EGR flow is managed. This post-cooling system reduces sludge and soot buildup in the EGR valve, minimizing maintenance.
• Diesel oxidation catalyst (DOC). The DOC is a ceramic catalytic converter designed to oxidize hydrocarbons in the exhaust stream.
• Selective catalyst reduction (SCR). The SCR is where diesel exhaust fluid (DEF; 32.5% urea) is injected & mixed into the exhaust stream. Diesel exhaust fluid is used to convert nitrous oxides into water & nitrogen. DEF fluid level must be maintained to ensure proper operation of the system and the truck (an empty DEF tank will result in reduced performance and speed).
• Diesel particulate filter (DPF). The DPF captures diesel particulate matter (soot) and uses active regeneration technology to heat the exhaust system periodically, completely burning soot build up & cleaning the filter.
Additional 6.7 Power Stroke Features
• The 6.7 liter engine blocks are manufactured by the American foundry company, Tupy. The engines are assembled in Chihuahua, Mexico.
• The pre-production 6.7 liter Power Stroke engine was nicknamed the “Scorpion” due to its unique turbocharger mounting location and exhaust/intake arrangement.
• Engine features 6 bolt main bearing caps.
• “Instant Start” glow plugs are said to provide quicker starts in even the coldest of weather.
• Compacted graphite iron block for reduced weight (160 lbs lighter than the 6.4L Power Stroke).
• Engine uses fractured cap Mahle connecting rods.
• Features piston cooling jets for lower piston temperatures. Oil is jetted into the bottom or the piston and travels through a cavity within the piston, cooling the top of the piston before exiting. This helps lower combustion temperatures and increase engine longevity.
• B20 biodiesel compatible.
• 6.7L Power Stroke receives 18% increase in fuel mileage over previous 6.4L engines.
The 6.7 liter engine includes a compacted graphite iron (CGI) block for greater strength while reducing weight, reverse flow aluminum cylinder heads (the exhaust ports are located in the lifter valley) with dual water jackets, six head bolts per cylinder, and 29,000 psi (1,999 bar) high-pressure common rail Bosch fuel system.
The fuel injection system delivers up to five injection events per cylinder per cycle using eight-hole piezo injectors spraying fuel into the piston bowl. This engine also supports B20 biodiesel, allowing greener fueling options of up to 20 percent biodiesel and 80 percent petroleum diesel. Garrett’s single-sequential turbocharger features an industry-first double-sided compressor wheel mounted on a single shaft. It combines the benefits of a small turbocharger (faster response) and a large turbocharger (ability to compress and force more air into the engine for more power) in one unit.
Output was originally 390 hp (291 kW) and 735 lb·ft (997 N·m), but shortly after production started, Ford announced an update to the new 6.7 liter diesel engine. The new engine control software makes the engine capable of 400 hp (298 kW) @ 2800 rpm and 800 lb·ft (1,085 N·m) @ 1600 rpm while achieving better fuel economy and without any physical changes to the engine.
All 6.7 liter engines already shipped to dealerships or purchased by customers can be upgraded to Fords new specifications with a free software update available at Ford dealerships.
6.7 Liter Power Stroke Key Specifications
The 6.7 liter Power Stroke Diesel was released in 2010 for the 2011 model year.
- Diesel particulate filter
- 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
2011 6.7 Liter Engine Initial Ratings
Peak torque: 735 lb-ft
Peak horsepower: 390 hp
2011 Post Launch Torque and Horsepower Upgrade
Peak torque: 800 lb-ft
Peak horsepower: 400 hp
Available for the 2011 6.7L Power Stroke through a PCM update.
2012-2014 6.7 Power Stroke Updates
• Increased torque and power numbers (released shortly after initial 6.7L release)
• Stamped steel lower oil pan with a conventional drain plug.
• The stud was removed on the oil cooler for easier servicing of the oil cooler.
• Crankcase ventilation sensor was introduced 2013 model year.
• Modifications to the Diesel Particulate Filter (DPF) and diesel particulate filter pressure sensor.
– DPF delta pressure sensor was incorporated in 2013 MY.
• Two NO sensors and modules.
– The second NOx sensor and module was added for the 2013 model year.
• Oil and coolant feed lines to the turbocharger have been updated.
2015 6.7 Power Stroke Model Year Updates
**These changes are mostly for the pickup, although some were applied to the chassis cab
• IROX coating used on the lower main bearing. (Update for pickup and chassis cab)
• Heavier crankshaft damper. (Update for pickup and chassis cab)
• Updated fan clutch.
• Exhaust Gas Recirculation (EGR) inlet temperature sensor. (Update for pickup only)
• Turbocharger with the following updates: (Update for pickup only)
– Lower intake to accommodate the new turbocharger.
– The electronic vacuum regulator valve and actuator was deleted.
– Wastegate was deleted.
• Change to the coolant flow through the EGR cooler. (Update for pickup and chassis cab)
• Fuel pressure and temperature sensor in the low pressure fuel system were combined into one sensor.
• New high pressure fuel pump and injectors: (Update for pickup only)
– The components physically look the same.
– Longer stroke in the fuel pump.
– All new injector tip.
• New up-pipes and downpipe including a new downpipe bracket. (Update for pickup only)
• Particulate matter sensor and module was added after the DPF.
2015 6.7 Power Stroke engines are rated at 440 horsepower (330 kW) and 860 lb·ft (1,166 N·m).
2015—2016 6.7 Liter Engine Specs:
- Turbo configuration: ‘GT37’ –single 72.5mm turbine and 88mm compressor
- Fuel System: High-pressure common-rail, Bosch CP4.2 injection pump, piezo electric injectors
- Engine: Power Stroke V-8
- Displacement: 6.7L
- Bore and Stroke: 3.90 x 4.25 inches
- Cylinders: 90-degree V-8
- Block: Compacted graphite iron
- Heads: Aluminum (reverse flow)
- Pistons: Forged-aluminum
- Valve train: OHV,four valves per cylinder
- Horsepower: 440 at 2,800 rpm
- Torque: 860 lb-ft at 1,600 rpm
- Emissions Equipment: EGR, DPF, SCR
- Engine Dry Weight: 970 pounds
2017 6.7 Liter engines saw yet another increase in torque while horsepower remained unchanged. The new engine produces 440hp at 2800RPM and 925lb-ft at 1800 RPM.
6.7 Power Stroke MPG
Some report an average of 20-21 MPG empty on the highway to 18-19 MPG mixed and towing. Actual fuel economy can vary quite a bit depending on driving style and actual use of the 6.7 Power Stroke engine. Nonetheless, it’s a pretty efficient engine overall and gets solid MPG.
We think Ford’s decision to produce their own diesel engine was a smart one. With the issues of the 6.0 Power Stroke, they needed to re-establish reliability in the brand. The design changes for the 6.7L are a huge part of it’s success.
Being the first medium duty diesel designed and built by Ford, they wanted a powerful as well as reliable engine. Ford set out to achieve this goal by first keeping cylinder heads held down. The 6.7 features six bolts per cylinder, no longer would they rely on four bolts per cylinder. The cylinder heads of the 6.7 engine also feature dual water jackets.
Another key change made in the head of the 6.7 engine was the rocker arms. There is a dedicated rocker arm for each valve. Previous generations of the Power Stroke engine had one rocker pushing on a bridge, actuating two valves.
With the 6.7, Ford also addressed common problems with some of the earlier Power Stroke engines from International, specifically the 6.0.
EGR system concerns historically have plagued all modern diesel engines equipped with them in one way or another. Some failures have been extremely troublesome and even lead to catastrophic engine failures. Head gasket failures and cooling system concerns where common on the 6.0 Liter engines, due to the oil and EGR cooling.
For the 6.7 engine, Ford opted to use two cooling systems. The primary cooling system is for the primary engine components (heads, block, etc). The other cooling system is to cool the EGR, fuel, transmission fluid, and charge air cooler (air to water on the 6.7 instead of air to air). By separating the cooling systems into two, Ford eliminated the concern created by hot exhaust gasses adding additional heat into the engine cooling system. They are also able to run them at different temperatures to optimize cooling.
The 6.7 Liter Power Stroke engines have proven to be fairly reliable. We do not see a large percentage of engines with serious issues. but they do have a few common problems that are outlined below.
Below are a few of the common issues with the 6.7 Power Stroke engine.
6.7 Power Stroke Exhaust Valves
The early 2011 6.7 liter engines had an issue where the exhaust valves would develop cracks and eventually chip a piece off into the cylinder, which would subsequently damage a glow plug, that would be the primary indicator of the exhaust valve’s failure. Engines built after March 15, 2011 shouldn’t have this issue, as it has been said the problem was found and corrected.
Exhaust Gas Temperature (EGT) Sensor Issues
One of the most common cause of check engine lights and stop safely warnings on the 6.7 are the Exhaust Gas Temperature (EGT) sensor failures. They are so frequent that Ford has issued a warranty extension to cover these sensors. Most of the time these sensors are easily replaced, with some requiring heating with a the torch and others using a machinist tap to repair the threads.
6.7 Power Stroke EGR Cooler Problems
In the 2011 6.7 liter engine, EGR cooler cores are known to become restricted, which is detected by the engine control software and will result in the Check Engine light being turned on and a DTC (Diagnostic Trouble Code) being set. While it is possible to find an issue with the EGR valve, Bypass valve or a sensor, the cause is commonly caused by the cooler being restricted and sometimes completely clogged with carbon.
Because the valve has been relocated from the cold side to the hot side the new EGR design. It effectively eliminated the carbon deposits forming on the EGR valve that occurred on the 6.0L and the 6.4L engines but now the carbon deposits in the EGR cooler core. The EGR cooler core can become completely clogged with carbon deposits in severe cases. If you have DTC P0401 stored in your PCM, the 6.7L Power Stroke EGR cooler replacement is likely the cure of your problems and is a relatively simple, straight forward process.
6.7L Power Stroke EGR Cooler Including Gaskets:
- BC3Z-9V425-A Application: 2011-2015 F-250 through F-550 Cooler
- FC3Z-9P455-A Application: 2015 F-250 through F-550 Gasket
- BC3Z-9P455-B Application: 2011-2014 F-250 through F-550 Gasket
In 2015 the coolant flow through the EGR cooler has been changed. The EGR cooler is carryover from the previous model year engine, but the secondary cooling system no longer cools the EGR gases. Both cooling elements in the EGR cooler are now cooled by the high temperature cooling system.
The ECT2 sensor has been removed from the EGR cooler and the hole plugged. On later 2015 models the EGR cooler is modified and the plug is deleted.
6.7 Power Stroke Coolant and Oil leaks
In the early years of the 6.7 liter engine, there was a high percentage of radiator, turbo base coolant seal, turbo coolant inlet fitting, and water pump leaks. The turbo coolant inlet fitting is rather easy to replace with the removal of the upper intake, but removal of the turbo charger for replacement of that block to turbo gasket is a much harder task.
Oil and coolant leaks that show up at the lower rear of the engine at the transmission converter housing more than likely originate up top. Both fittings are located at the top of the center housing of the turbo and a clear view of them is obstructed by the upper intake manifold.
Radiator replacement is complicated by the size, angle of mounting, and the addition of the secondary cooling system radiator.
2012 – 2014 upgrades include the cooling and lubrication lines going into the turbocharger which have been changed from quick connections to bolt fasteners. This improves both sealing and durability.
We have come across a few oil leaks coming from the front cover area because of the loosening of the vacuum pump bolts.
6.7 Power Stroke Turbocharger Faults
There have been numerous turbochargers being replaced due to failure. Turbocharger failure is a direct result of using a smaller than adequate turbocharger to produce the amounts of boost and air flow required on this engine application. Turbocharger over-speed is likely the main problem and usually is intensified by aftermarket performance enhancements. Your problems can be solved with aftermarket performance turbocharger assemblies on earlier model 6.7L Power Stroke engines.
2015 6.7 Liter Model Year Turbocharger Updates
• DualBoost turbo replaced with a single boost turbocharger (similar to the one found on the chassis cab vehicle)
• Wastegate no longer on turbo
• Larger turbo
The turbocharger uses variable vanes that surround the turbine wheel to dynamically adjust turbocharger speed using exhaust gases. During engine operation at low speeds and load, the vanes are closed to accelerate exhaust gases across the turbine wheel to help quickly increase turbocharger wheel speed. At high speeds the vanes open to prevent turbocharger overspeed conditions.
The turbocharger provides up to approximately 206.84 kPa (30 psi) boost at up to 130,000 RPM.
Separate oil and water feeds flow through the turbocharger mounting pedestal to lubricate and cool the turbocharger and eliminate as many external connections as possible.
Model year 2017 and above are now using a larger turbocharger to reduce failures (and create more power!).
6.7 Power Stroke Turbochargers
- FC3Z-6K682-A Application: 2015 F-250 through F-450 Wide Frame (Pickup)
- BC3Z-6K682-A Application: 2011-2014 F-250 through F-450 Wide Frame (Pickup)
- BC3Z-6K682-B Application: 2011-2015 F-350 through F-550 Narrow Frame (Chassis Cab)
6.7 Power Stroke – Less Common Issues
fuel rail pressure sensor failures, fuel rail temperature sensor failures, broken injector return lines, NOx senors (now under a TSB), and other repairs that require the replacement of the entire SCR system. High pressure fuel system contamination is a very common and expensive repair but occurs most frequently from user error, due to water contaminated fuel or DEF additions to the fuel tank.
Most problems with the 6.7 liter Power Stroke engine are isolated incidents – failures or faults are experienced by a low percentage of owners, particularly on early engines. While issues are expected from a clean, late model engine, especially one as advanced as the 6.7 liter Power Stroke, there have been very few common issues with Ford’s new diesel platform.
|Engine:||Ford Motor Company 6.7L Power Stroke diesel V-8|
|Displacement:||6.7 liters, 409 cubic inches|
|2011 to present model years|
|Block/Head Material:||• Compacted graphite iron engine block (CGI) with 6 bolts per main bearing cap
• Aluminum cylinder heads with 6 head bolts per cylinder
|Compression Ratio:||16.2 : 1|
|Bore:||3.90 inches (99 mm)|
|Stroke:||4.25 inches (108 mm)|
|Aspiration:||• Garrett GT32 DualBoost variable geometry single sequential turbocharger, wastegated, 2011 – 2014 MY
• Garrett GT37 single VGT, 2015 – 2016 MY
• Single sequential turbocharger, 2017 MY
• Air-to-water intercooler (charge air cooler or CAC)
|Injection:||• Direct injection, 30,000 psi high pressure common rail
• 19mm Piezo actuated injectors with 8 hole nozzles
• Bosch CP4.2 high pressure injection pump
|Valvetrain:||Conventional pushrod OHV, cam in block, 4 valves per cylinder (32 valve)|
|Cooling System:||Dual cooling systems; high temperature circuit for engine, low temperature circuit for transmission cooler, CAC, etc|
|Oil Capacity:||13 quarts w/ filter (2011 – 2016 MY), 15 quarts w/ filter (2017 MY)|
|Oil Requirements:||• CJ-4 or CJ-4/sm engine oil is required to ensure emissions system compatibility
• 10W-30 is the preferred motor oil viscosity for normal use
• 5W-40 or 15W-40 engine oil is recommended for severe duty or biodiesel applications. Viscosity recommendations vary with ambient temperature; refer to owners manual
|Engine Weight:||Approx. 1,100 lbs w/ oil, 990 lbs dry|
|Emissions Equipment:||EGR, DOC, SCR, DPF|