The Cummins 5.9L Turbodiesel Engine, also known among the diesel community as the "12 Valve" was the first diesel engine in the Dodge Ram lineup starting in 1989. The 1st Generation Ram 2500s and Ram 3500s utilized this engines 160 HP and 400 lb-ft of torque as well as its incredible dependability. This engine is highly sought after in the diesel community not only for its ease of maintenance and repair, but also for its superior build quality. The engine came off the production line massively under-powered, as the stock internals were found out to be much stronger then they were initially rated for. From 1989 to 1993, the 12 Valve was paired with VE44 Injection pump, which was succeeded by the P1700 Injection Pump. The P1700, which is commonly reffered to as the "P-Pump," is renowned by the diesel community for both its durability and its power potential.
Common Engine Issues and Resolutions
The Killer Dowel Pin The Largest and most detrimental flaw of the 12 Valve Cummins has to do with a steel dowel pin located in the front timing gear-case. Due to the constant vibrations and heat cycles of the engine, the pin tends to wobble out and fall into the gear-case. When this happens, it is more than likely that the pin will hit or jam into one of the timing gears causing it to either shoot out and through the side of the case, or destroy and jam the gears. This causes the Cams, valves, and pistons to quite literally self-destruct, and cause a cataclysmic engine failure. Fortunately for 12 Valve owners, there is a repair kit that costs under 100$ to help replace and easily secure this pin, thus avoiding this issue altogether. If you would like to purchase this kit, or look at other ones, click here.