Chrysler 3.7L V6 PowerTech Engine: Specs, Problems, and Reliability. The 3.7 L V6 PowerTech (also referred to as 3.7 EGK and Dodge 3.7 L Magnum) is a 3.7-liter six-cylinder gasoline engine developed by Chrysler and produced from 2002 to 2012. This 3.7 L engine a very long time was a base power option for the Dodge Ram pickup truck, but also can be found on the Jeep Liberty/ Cherokee, Jeep Commander, Jeep Grand Cherokee, and Dodge Dakota. The PowerTech engines were never used on any passenger car but were reserved for truck and SUV use only. Let’s take an in-depth look at the 3.7 L PowerTech engine design, its common problems, reliability, and longevity.
The 3.7 L PowerTech/Magnum engine is basically a 4.7 V8 version without two cylinders. Like the PowerTech V8, the 3.7 L V6 engine has a cast-iron cylinder block along with a 90 degrees angle between cylinder banks. This angle has been maintained in order to reduce the production and combine cost of two engines. All V6 engines with a 90-degree design have a crankshaft configuration problem.
You can make a crankshaft in the style of V8: use one crankpin for two cylinders located opposite each other. It is simpler, more reliable, but there is a problem of ignition in the cylinders because of an uneven alternation: 90 – 150 – 90 – 150 – 90 – 150 (720 degrees total). To achieve even fire (every 120 degrees), the engine was equipped with a 30-degree split pin crankshaft. To deal with the first order inertia forces, there is a gear-driven counter-rotating balance shaft mounted between the banks. The engine uses fracture-split, forged powder metal connecting rods and lightweight aluminum pistons.
This 3.7 V6 has aluminum cylinder heads with two valves per cylinder, centrally located spark plugs, and single overhead camshafts on each cylinder bank. Each camshaft is driven by its own timing chain. The intake and exhaust valves are actuated by cams via roller rocker arms equipped along with hydraulic valve clearance adjusters. Cylinder heads are insulated from above along with stamped steel cylinder head covers.
The three-piece intake manifold is made of lightweight composite material (plastic) and has individually tuned runners for each cylinder that shorter than on the 4.7 L V8 engine. There are two knock sensors located under the intake manifold that helps prevent pre-ignition. The engine uses electronically controlled sequential fuel injection and electronic ignition.
In 2004, the supplier switched from the JTEC engine control unit to NGC ECU which also controls an automatic transmission. In 2005, the 3.7-liter PowerTech engine went through a revision. 2005+ version features an increased compression ratio of 9.7:1, reshaped combustion chambers, a new cam profile, new piston rings, and plastic cylinder head covers. The last update in 2007 included an electronic throttle body and EGR implementation.
Eventually, the PowerTech V6 engines were replaced by 3.6-liter Pentastar V6 engines – more technically advanced engines with an optimal 60-degree cylinder block design.
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3.7 V6 PowerTech/Magnum Engine Problems and Reliability
The PowerTech 3.7-liter six-cylinder engines are durable and pretty reliable. Among the shortcomings, we can mention only a bit rough operation in terms of vibration and noise, in addition to relatively high fuel consumption compared to producing power, at the same time the difference in the 3.7 V6 vs. 4.7 V8 MPG is almost negligible (close to 2-3 MPG).
The PowerTech family has two common problems for V8s and v6s. The first of them is stuck lash adjusters. In addition to deteriorating engine performance, this can also cause the rocker to move out of its working position, after which the corresponding valve completely stops opening. The reason is in thick oil or stretched periods of an oil change. The second problem is regularly for the eight-cylinder engine but also happens to V6s. Valve seats are not sufficiently secured in the aluminum head and when overheating, the likelihood of some valve seats falling out increases significantly.
The recommendations for expanding life of the 3.7 L V6 PowerTech engine are quite simple: you need to monitor the condition of timing chains and their tensioners, a water pump, the crankcase ventilation system, do not overheat the engine, do not pour too thick oil and do not delay the time for changing the oil. The engine life of 3.7 V6s concerns 200,000 miles (320,000 km).
Chrysler 3.7L V6 PowerTech Engine Specs
- Manufacturer: Chrysler’s Mack Avenue engine plant, Detroit, Michigan
- Production years: 2002-2012
- Cylinder block material: Cast iron
- Cylinder head material: Aluminum
- Fuel type: Gasoline
- Fuel system Sequential: fuel injection
- Configuration: V
- Number of cylinders: 6
- Valves per cylinder: 2
- Valvetrain layout: SOHC
- Bore, mm: 93.0 mm (3.66 in)
- Stroke, mm: 90.7 mm (3.57 in)
- Displacement, cc: 3,701 cc (225.8 cu in)
- Type of internal combustion engine: Four-stroke, naturally aspirated
- Compression Ratio: 9.8:1; 9.7:1 – 2005+
- Power, hp: 210 hp (157 kW)/5,200
- Torque, lb ft: 235 ft-lb (319 Nm)/4,000
- Engine weight: –
- Firing order: 1-6-5-4-3-2
- Engine oil weight: SAE 5W-30 (SAE 5W-20 from 2007)
- Engine oil capacity, liter: 4.7 l (5.0 qt)
- Oil change interval, mile: 6,000 (10,000 km)/6 months
- Applications: Dodge Ram 1500, Dodge Dakota, Dodge Durango, Dodge Nitro, Jeep Liberty/Cherokee (KJ, KK), Jeep Grand Cherokee (WK/WH), Jeep Commander (XK), Mitsubishi Raider
