Welcome to the JeepSpecs.com in-depth page on WJ Generation Jeep Grand Cherokee engine specification Guide. We have organized as much information as we could find into a helpful article below. Is something incorrect or missing? Please get in touch with us and we’ll fix it!
4.0 liter I-6
4.7 liter V-8
4.7 liter V-8 High Output
Jeep has used three different engines for the WJ series (plus a couple of 5-cylinder diesels for the export market):
4.0 liter I-6 (242 cu in., 195 bhp)
The standard in-line 6 cylinder engine was significantly reengineered in 1999. Upgrades included new cylinder heads with reduced-area exhaust ports, new exhaust manifolds, a new 50% more efficient slitter-vane water pump that added two horsepower, a new elastomer-coated steel intake manifold gasket, a two-piece high silicon-molybdenum alloy cast-iron exhaust manifold, automated belt tensioner and a new laminated oil pan. These refinements added more power (10 bhp), a 5db quieter operation with an enhanced lower “throaty” sound quality, and cleaner emissions.
The all-new 4.7-liter V-8 engine offers more power, less weight (438 lbs), increased fuel efficiency and lower emissions than the 5.2-liter engine it replaced. An incredibly detailed tech analysis, written by Richard Ehrenberg in 1999, can be found here: Chrysler’s New Cammer.
4.7 liter V-8 HO (287 cu in., 265 bhp)
A High Output version of the 4.7L was introduced starting with the 2002 model year. The performance modifications added 30 horsepower and 30 Ft.-Lb. of additional torque. The HO engine is designed to run perfectly on standard octane fuel, but for maximum performance premium fuel is recommended.
The HO engine is standard on all 2002-2004 Overland models, and is optional on the 2002-2004 Limited 4WD models. In the 2004 model year, Jeep offered the HO as an option on three special models, the Freedom, Columbia and Rocky Mountain editions. It has not been available on the Laredo, Laredo Sport or SE (Special Edition) models. All 2002 models with the HO engine featured a nice custom chrome exhaust tip. This was, unfortunately, decontented starting with 2003 model year production.
The 5.7-liter V-8, which puts out 325 horsepower with 390 lb.-ft of torque, debuts for model year 2005 in the all-new Grand Cheokee. As described by DC, “The engine’s unique two-valve Hemispherical combustion chamber (which gives the engine its “Hemi” name) within an aluminum head provides impressive air flow, torque and power, and gives the engine its throaty rumble. The engine started production at the Salitillo plant in Mexico in June of 2002. More than 35,000 engines per month have been rolling off the assembly lines. The engines will be used in pickups, Dakotas, Durangos, Grand Cherokees and other large Chrysler vehicles like the 300 series.
The Hemi engine in the Grand Cherokee includes Cylinder Deactivation, a feature which shuts down four of the eight cylinders during idling and light-demand situations, such as highway driving, by electronically controlling the flow of oil to valve lifters. Engines with this enhanced fuel-saving multi-displacement feature started production in January of 2004.
Facts and features:
The 5.7-liter Hemi® Magnum V-8 engine is an internally balanced pushrod (OHV) 90-degree V-8. The cast iron block is a deep skirt and cross-bolted design with cylinder bore spacing the same as the engine it replaces.
The aluminum cylinder features a two-valve per-cylinder, Hemispherical combustion chamber with dual spark plugs and a coil over plug ignition for best-in-class airflow and power. An Integrated Air Fuel Module (IAFM) incorporates the function of 26 individual components in the induction and fuel system, thereby reducing cost, weight and engine plant complexity.
A systematic approach to sealing, using premium elastomeric materials and state-of-the-art practices, helps ensure a leak-free, weep-free engine. The power plant’s simple and efficient design means servicing and repairs are easier and less costly.
Three different views of the Hemi engine.
Grand Cherokee 5.7L Hemi Specifications
Description: Eight cylinders, 90-degree V-type, liquid cooled. Deep-skirt cast iron block with cross-bolted main bearing caps, aluminum alloy heads with Hemispherical combustion chamber
Bore x stroke: 3.92 x 3.58 (99.5 x 90.9)
Camshaft: Silent chain, 5-bearings. Bi-metal material except number 3 Babbit. Deep-fillet rolled journals for improved fatigue life, press fit damper to minimize torsional vibration
Compression Ratio: 9.6:1
Connecting rods: Forged with cracked cap, powder metal, bi-metal bearings