

Fortunately, all of the other problems are relatively minor in nature. Out of all the problems with the 5.9 engine, the only one that is potentially catastrophic is the killer dowel pin. The engine went through three turbocharger changes, from the Holset H1C to the Holset WH1C, to the Holset HX35. Additionally, in 1991.5 an air-to-air intercooler was added. In 1994, the VE44 rotary injection pump was replaced with the P7100 “P-pump”. Over its 10yr lifespan, the 5.9 Cummins went through a number of revisions. The inline-6 cylinder 12v diesel produced 160-215hp and 400-440lb-ft of torque. The 5.9 Cummins 12v ran from 1989 until 1998 when it was phased out for the 5.9L Cummins 24v, also known as the ISB 5.9. It is the big brother to the 3.9L Cummins 4BT, which is essentially a 12v 6BT minus 2 cylinders. In 1989, Cummins and Dodge partnered with the 12v launching in Dodge /Ram’s 2500 & 3500 trucks. The 12v was released by Cummins in 1984 primarily for farm equipment. The legendary Cummins 12v, also known as the 5.9L 6BT, is widely regarded as the best diesel engine ever.
