Chrysler 3.7L V6 PowerTech Engine (Design, Issues & Reliability)

✔ This article has been fact checked.

The Chrysler 3.7L V6 PowerTech is a six-cylinder gasoline engine producing around 210 hp and 319 nm of torque, it was made by Chrysler from 2002 to 2012. It is also referred to as the 3.7 EGK and the Dodge 3.7L Magnum.

This 3.7L engine, which was previously only offered in the Dodge Ram pickup truck, is now also offered in the Jeep Liberty/Cherokee, Jeep Commander, Jeep Grand Cherokee, and Dodge Dakota.

PowerTech engines were never installed in passenger cars; instead, they were solely used in trucks and SUVs. 

Table of Contents:

• Design

• Specs

• Problems & Reliability

• Images

Chrysler 3.7L V6 PowerTech Engine Design

The 3.7L V6 engine has a cast-iron cylinder block with a 90-degree angle between the cylinder banks, similar to the PowerTech 4.7L V8. In order to merge two engines and reduce production costs, this angle was kept.

A problem with the crankshaft arrangement affects all 90-degree V6 engines. A V8-style crankshaft can be created by using one crankpin for two cylinders that are opposite each other.

It is less complicated and more reliable, but it has a problem with the cylinders ignition because of an uneven rotation: 90 - 150 - 90 - 150 - 90 - 150 (720 degrees total).

To encourage equal burning, the engine uses a 30-degree split pin crankshaft (every 120 degrees). A gear-driven counter-rotating balancing shaft is placed between the banks to deal with primary inertia forces.

The engine has lightweight aluminium pistons and fracture-split, forged metal connecting rods.

This engine has two valves per cylinder, spark plugs positioned in the centre of the cylinder, and single overhead camshafts on each cylinder bank. The timing chain for each camshaft is independent.

To control the intake and exhaust valves, cams employ roller rocker arms with hydraulic valve clearance adjustments. Stamped steel cylinder head covers protect the top of the cylinder heads.

The lightweight composite material three-piece intake manifold has shorter individually adjustable runners for each cylinder than on the 3.7L PowerTech V6 compared to the 4.7L V8 engine.

Under the intake manifold, two knock sensors prevent pre-ignition and knocking. Sequential fuel injection and ignition are controlled electronically in the engine.

In 2004, the NGC ECU, which also controls the automatic transmission, replaced the JTEC engine control unit.

2005+ Engine

The 3.7L PowerTech V6 engine was redesigned in 2005.

Changes include:

• a 9.7:1 compression ratio

• new piston rings

• revised combustion chambers

• plastic cylinder head covers

The most recent additions were an electronic throttle body and exhaust gas recirculation (EGR), both of which were introduced in 2007.

The 3.6L Pentastar V6 engines, which were more technologically advanced and featured a 60-degree cylinder block design, eventually replaced the 3.7L PowerTech V6 engines.

Engine Specs

• Manufacturer: Chrysler’s Mack Avenue engine plant, Detroit, Michigan

• Production years: 2002-2012

• Cylinder block material: Cast iron

• Cylinder head material: Aluminium

• Fuel type: Gasoline

• Fuel system: Sequential fuel injection

• Configuration: V

• Number of cylinders: 6

• Valves per cylinder: 2

• Valvetrain layout: SOHC

• Bore: 93.0 mm (3.66 in)

• Stroke: 90.7 mm (3.57 in)

• Displacement: 3,701 cc (225.8 cu in)

• Type: Four-stroke, naturally aspirated

• Compression Ratio: 9.8:1, 9.7:1 (2005+)

• Power: 210 hp (157 kW) at 5,200 rpm

• Torque: 235 ft-lb (319 Nm) at 4,000 rpm

• Firing order: 1-6-5-4-3-2

• Engine oil weight: SAE 5W-30 (SAE 5W-20 from 2007)

• Engine oil capacity: 4.7 litres (5.0 qt)

• Oil change interval: 6,000 miles (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

Problems & Reliability

PowerTech's 3.7L six-cylinder engines are incredibly durable and reliable. However, the difference between this 3.7L V6 and the 4.7L V8 fuel economy is very small. Only a minor amount of harsh operation in terms of vibration and noise can be felt compared with the V8 engine.

With V6 and V8 engines, the PowerTech series often encounters two issues.

• The first is clogged lash adjusters. This might force the corresponding valve to entirely close, forcing the rocker to shift out of its operational position and lowering engine performance. The culprits are thick oil or not being serviced regularly. 

• The second issue is more common with the V8 PowerTech engines, though it can also occur with V6s. The valve seats in the cylinder head are not adequately secured, which increases the likelihood that specific valve seats will pop out when the engine overheats.

Don't overheat the engine, don't use too thick oil, and don't put off changing the oil for too long. Also keep an eye on the timing chains and tensioners, the water pump, and the crankcase ventilation system.

These 3.7L V6 PowerTech engines may last for 200,000 miles before needing replacement.

Images

Below are images of the Chrysler 3.7L PowerTech engine.

Sources