Ford 6.7L PowerStroke Engine (Specs, Reliability & Issues)
The 6.7L Power Stroke engine is a turbocharged diesel engine with a displacement of 6.7 litres. Ford Motor Company started developing a new diesel engine for the Ford Super Duty in-house in 2008.
This new product was nicknamed the Scorpion throughout its development, and when Ford unveiled it in 2011, the engine was already known as the 6.7 Power Stroke. The 6.7L Power Stroke engine from Ford superseded the 6.4L Power Stroke, becoming the first Power Stroke engine not made by International Navistar (nearly 30 years of partnership).
Unlike most modern diesel engines, the 6.7L Power Stroke's cylinder block is comprised of compressed graphite iron, rather than hefty cast iron (CGI). Its deep-skirt block contains nodular iron six-bolt main caps, which are more frequent on the 7.3L Power Stroke, instead of a bed plate like the 6.4L.
In addition to the CGI material, this block arrangement resulted in substantial weight reductions over the 6.4L predecessor. A steel crankshaft, Mahle powdered metal cracked-cap connecting rods, and Federal Mogul cast-aluminum pistons are also included in the 6.7 Power stroke. To boost strength, the connecting rods feature a 45-degree rotated end cap.
Piston cooling jets were installed in the engine to reduce piston and combustion temperatures. This has a good impact on the engine's lifespan. All 6.7L blocks are made by Tupy, an American foundry.
The 6.7L Power Stroke engine from Ford is the world's first to employ cast-aluminum cylinder heads. They're made to flow in the other direction. There are valves on each cylinder (two intake and two exhaust valves; 32 valves total). Rocker arms and pushrods are unique to each valve.
Intake air enters via perforations in the valve covers, while exhaust gases depart through the lifter valley's exhaust manifolds (in a traditional V8 engine, the exhaust exits from the outside). A Garrett GT32 DualBoost variable geometry single sequential turbocharger is also located in engine valley (SST).
The exhaust volume of this system is lowered, allowing the engine to respond more dynamically. A water-to-air intercooler attached to the engine's secondary cooling system cools the compressed and hot intake air.
The EGR circuit, gearbox fluid, and fuel cooler are all cooled by this powertrain secondary cooling system. Each cooling system, including the main and powertrain cooling systems, has its own water pump, thermostats, degas bottle, and radiator.
A high-pressure common rail direct injection system is standard on the 6.7L Power Stroke. The Bosch CP4.2 fuel pump delivers fuel to the 19 mm Piezo-driven Bosch injectors with 8 hole nozzles at 30,000 psi. Every combustion cycle, the fuel injectors allow for five occurrences.
The GT32 SST turbocharger was replaced in 2015 by the Garrett GT37 with a single VGT turbocharger. The GT37 has an 88 mm compressor wheel and a 72.5 mm turbine wheel, compared to the GT32's 64 mm.
A higher-flowing Bosh CP4.2 high-pressure fuel pump with a larger stroke and updated injector nozzles were also added to the fuel system. As a result of the modifications, the engine can now produce much more power.
Manufacturer: Ford Motor Company, Chihuahua, Mexico plant.
Production years: 2011-present
Cylinder block material: Compacted graphite iron
Cylinder head material: Aluminium
Fuel type: Diesel
Fuel system: Common rail direct injection
Number of cylinders: 8
Valves per cylinder: 4
Valvetrain layout: OHV
Bore: 99.1 mm (3.9 in)
Stroke: 108.0 mm (4.25 in)
Displacement: 6,700 cc (406 cu in)
Type: Four-stroke, turbocharged
Compression Ratio: 16.2:1
Power: 270-450 hp (201-335 kW) at 2,400-2,800 rpm
Torque: 675-935 lb-ft (915-1268 Nm) at 1,600-1,800 rpm
Engine weight: 970 lbs (440 kg)
Firing order: 1-3-7-2-6-5-4-8
Engine oil weight: CJ-4 or CJ-4/sm, SAE 10W-30 (normal use), SAE 5W-40 or 15W-40 (for heavy-duty or biodiesel applications)
Engine oil capacity: 12.3 litres (13 qts) - with oil filter
Oil change interval: 7,500 miles (12,000 km) or 12 months
Applications: Ford F-250, Ford F-350, Ford F-450, Ford F-550, Ford F-650, Ford F-750
Problems & Reliability
The 6.7L Power Stroke diesel engines from Ford are strong, long-lasting, and dependable, with just a few downsides. The 6.7L Power stroke's cylinder heads are no longer secured by four bolts per cylinder, which represents a significant increase in dependability.
On each cylinder, there are now six bolts. As a consequence of head bolt tension and head gasket failure, the risk of a burst head gasket and coolant/oil within the cylinder is reduced.
Turbocharger failure is the most serious issue that the 6.7 Power Stroke might face. Engines having a very sophisticated turbocharger with ceramic bearings (such as the small GT32 SST) were prone to premature failure in the early years of manufacturing.
A new turbocharger assembly with more dependable steel ball bearings on the turbo shaft is included in the most recent engines. The bulk of turbo-related problems have been documented on 2011 and 2012 models so far.
On 2011 engines, glow plugs were fragile and may easily break out, causing catastrophic engine damage inside the cylinders. It's OK to swap them out for the most recent ones.
Soot fouling on the EGR cooler and valve, as well as difficulties with the EGR temperature sensor and clogged DPF filters, are all causes for concern. It's possible that coolant will leak around the turbocharger and from the cooling system's main radiator.
The 6.7 Power Stroke engine has proved to be a relatively reliable engine in general. This diesel engine requires regular oil changes and the use of high-quality motor oil that fulfils Ford's lubricity standards. The engine will endure hundreds of thousands of kilometres if properly maintained.