2004 Mitsubishi Endeavor - Powertrain

The 2004 Mitsubishi Endeavor's drivetrain is designed to match the nimble chassis' handling capability with superior performance and flexibility for the class. All Endeavors are equipped with the same 3.8-liter V6 engine and four-speed Sportronic(tm) transmission combination, but can be configured as either front-wheel or full-time all-wheel-drive S.U.V.s.

Engine

The 2004 Mitsubishi Endeavor's sporty, stylish exterior design covers an engine that's assembled to deliver driving excitement, responsiveness, and rugged durability. All Endeavors are powered by a transversely mounted 3.8-liter, 60-degree V6 engine designed to engage drivers with a broad, responsive torque curve that helps deliver spirited performance.

The engine, designated 6G75, is an evolution of the smooth and powerful 3.5-liter V6 that powers Mitsubishi's Montero Sport. The new 3.8-liter displacement is the result of an oversquare 95.0 mm bore combined with a 90.0 mm stroke to achieve its 3828 cc displacement. In the interest of durability, the 3.8-liter engine's pistons are high pressure castings attached to forged steel connecting rods that swing from a heat-treated forged steel crankshaft. The high nickel content cast-iron, 60-degree engine block is dimensionally taller than the 3.5-liter engine's block and features revised oiling passages for improved lubrication and durability. In addition, the new 3.8-liter block is a new casting that has been structurally enhanced for additional cylinder-bore rigidity and includes improved chassis mounting points to reduce vibration and harshness. A pair of single-overhead-cam, four-valve-per-cylinder, aluminum heads sit atop this cast-iron block; their intake and exhaust port volumes and valve diameters have been carefully designed to maintain optimal mixture velocity at low to mid-range rpm to help deliver the best off-the-line and highway passing response. This free-revving engine package produces a peak of 215 horsepower at 5000 rpm with peak torque of 250 pound-feet occurring at 3750 rpm.

Induction

Fuel and air delivery to the combustion chambers of Endeavor's 3.8-liter motor is governed by a throttle-by-wire control system that eliminates the mechanical control between the accelerator pedal and the throttle plate. For Endeavor, the throttle-valve-control micro-processor has been integrated into the vehicle's main ECU. With this arrangement, inter-processor communication otherwise transmitted by a complex body of harnesses and connectors is now handled by a circuit board that improves the system's reliability and capability. With the traction control feature that is available on the Endeavor Limited, the throttle control computer receives data from wheel speed sensors to govern engine speed and regain traction when necessary.

An injection-molded, thermoplastic intake manifold directs airflow to each of the cylinder head's intake ports. The thermoplastic material offers a substantial weight savings (2 kgs.) over a comparable cast-aluminum manifold and helps lower the engine's center of gravity in the chassis. The intake manifold's port shape and volume is molded to produce the ideal mixture quality and velocity to allow the motor to produce the widest possible torque curve and yield responsive performance across the entire rpm range. The thermoplastic manifold also retains less heat than a cast-iron manifold to help deliver a cooler, denser ambient air charge to help realize an increase in mixture quality.

Cold Air Intake system

Endeavor is fitted with a cold-air induction system that feeds ambient air to the thermoplastic intake manifold and is designed to help improve engine performance while also controlling the levels of air-intake suction noise. The shape of the air inlet duct is designed to guard against the ingestion of water or snow, and draws large volumes of cool, dense, onrushing air from the grille opening.

A sound absorbing resonator attached to this intake ducting helps control suction noise. The Endeavor's intake system removes particulate from the incoming air using a low-restriction filter element that is contained in a sturdy air cleaner housing. A resonator is also used on the injection molded thermoplastic intake hose that leads from the air cleaner assembly to the engine.

Fuel Delivery System

The 2004 Mitsubishi Endeavor relies on a sophisticated, electronically controlled multi-point fuel injection system to ensure precision fuel delivery -- coupled with throttle-by-wire control that offers the advantage of a computer controlled and instantaneous acceleration response. The fuel delivery is handled by six injectors mounted in a lower injection manifold that are fed pressurized fuel by a plate-style delivery pipe. The cross section of the fuel-rail reveals the plate-style design that absorbs fuel pulsation, and helps generate consistent fuel spray patterns and better atomization. The Endeavor's fuel injectors are designed with additional tiny nozzle holes that help increase mean droplet size improving fuel atomization by 50 percent over previous injectors. The Endeavor's electric fuel pump module integrates the fuel filter and hi-volume/hi-pressure pump into one assembly, reducing the number or parts, connections, reducing the potential for leaks and improving overall system reliability. In the interest of the electrical fuel pump's durability, the material used for the commutator's brushes are composed of carbon instead of copper.

The Endeavor's in-tank mounted fuel pump relies on a return-less fuel plumbing to the engine bay from the rear of the vehicle using a return-less fuel plumbing system. By eliminating the need for a return line, the amount of heat transferred from the engine to the fuel tank has been minimized to help keep the fuel supply as cool as possible resulting in a reduction in fuel vapor emissions.

Exhaust

The Endeavor utilizes high flow, welded tubular exhaust manifolds to expel the engine's spent fumes. The catalytic converter is integrated into the clamshell assembly near the cylinder heads where they can sooner achieve effective operating temperature, retain heat and promote quicker, more efficient exhaust catalyzation and increase emissions performance. The rest of the stainless steel exhaust system is designed to utilize a minimum number of hanging points to lessen the amount of vibration transmitted to the body. The Endeavor's stainless steel exhaust system is mandrel bent in two configurations, one for the front-wheel-drive Endeavor and another for the all-wheel-driver version that includes subtle bends for clearance of the additional mechanical gear located at the rear of the vehicle. A high flow muffler minimizes back-pressure while also producing a pleasant, sporty exhaust note.

Cooling System

The Endeavor is equipped with a high-capacity aluminum radiator with plastic tanks that is very effective at transferring heat from the circulating coolant. This radiator uses dual electrical fans that are mounted in an airflow efficient shroud for optimal cooling in traffic. Two sizes of radiator cores are available; a 757 mm x 500 mm x 16 mm is standard while the all-wheel-drive models equipped with the optional Full-Size Spare and Towing Prep package receive a larger 757 mm x 500 mm x 27 mm radiator.

The thermostatically governed electric fans are controlled by pulse width modulation which controls the fan motor speed by varying the level of current to meet the engines' cooling needs and create a smooth, step-free, progressive fan-cooling cycle.

Automatic Transmission

The Endeavor's four-speed automatic transmission integrates next-generation electronic controls with more refined mechanical technologies to offer superior driving satisfaction, performance, and durability. The Endeavor's version of the four-speed automatic builds upon years of accumulated development in design and production technologies to produce a transmission with superior structural rigidity, enhanced durability, improved efficiency and reduced weight.

The Endeavor's transmission is equipped with the latest version of the INVECS II processor that helps the transmission match its shifting actions to both the road conditions and the operator's driving style and inputs. INVECS II provides drivers with what they perceive to be the optimum shift points. It also includes a "learned control" function whereby the computer measures the timing of the driver's accelerator inputs and tailor's shift action accordingly for softer or firmer shifts. All Endeavor four-speed transmissions also are equipped with Sportronic(tm) mode that offers dynamic manual shifting by simply moving the shift lever into the sports mode gate for more fun-to-drive control. Helping ensure component longevity, the Endeavor's transmission is equipped with both water and air coolers for the transmission fluid that are mounted in series. The water cooling element is mounted within radiator's lower tank as a double-pipe system while the air-cooled tank is mounted on the inside of the left fender.

Transfer Case

All-wheel-drive Endeavor models utilize a center differential equipped with a spider gear and viscous coupling arrangement to realize a full-time, 50/50 torque split, sharing power to all four wheels. Refinement to the components of this center differential includes finer pitched hypoid gears for noise reduction. Aiding durability and towing performance, the transfer differential case can be equipped with a Towing Prep package that includes a hypoid gear oil cooler. The viscous coupling action of the center differential is designed to realize the best possible engagement of the four wheels upon acceleration to generate superior off-the-line performance.

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