The 3.5L V6 included a number of firsts for Chrysler when it was introduced over a decade ago:
A water pump with a molded plastic impeller, the first of its kind used by any domestic vehicle manufacturer. The scroll-shaped impeller uses 3 to 4 less horsepower than a stamped-steel impeller. It is also rustproof, quieter and provides better balance. But there have been instances where debris in the cooling system has caused accelerated erosion and wear of the impeller, causing the engine to overheat because of reduced coolant flow. Replacement water pumps should have the same design as the original to maintain the same cooling characteristics, says Chrysler.
A compression ratio 10.4 to 1, the highest of any standard Chrysler production engine since the 1970s. Yet it can run on mid-grade (89 octane) unleaded fuel thanks to dual knock sensors.
A six-piece crankshaft thrust bearing with separate side sections that provide better alignment with the block and reduce wear.
A north-south orientation in the engine bay instead of the more common east-west transverse configuration for a domestic FWD car.
A returnless electronic fuel injection system that has no return line from the fuel rail back to the fuel tank. The pressure regulator for the Sequential Multi Point Injection (SMPI) system is located in the gas tank with the electric fuel pump. The design eliminates some plumbing and also keeps the fuel cooler because it does not circulate back and forth between the engine and fuel tank. It is the same SMPI fuel system that is also used on Chrysler 5.9L Magnum and 5.2L truck engines, the 3.0L SOHC, 3.3L and 3.8L passenger car V6s, and the 2.5L, 2.4L 2.2L and 1.8L engines from 1993 forward.
Lightweight connecting rods that lack the usual balance pads. Balance is achieved by select-matching the rods with the pistons (an important point to remember if you ever have to replace a rod. Torque on the cap bolts is 40 ft.-lbs. plus an additional 90 degree twist.