2003 5.9 cummins engine serial number location

The history of the 5.9 liters ISB engine was ended in 2007. The HO Cummins wasn't offered in California due to strict emissions regulations in this state. In the last year, 2004, HO models had an additional 20 horsepower and 45 lb-ft of torque. The 2003 model year high output version offered perceptible 70 horsepower and 95 lb-ft more than the standard output ISB engine. A high output or HO 5.9L Cummins had a higher compression ratio of 17.2:1, a more massive flywheel, changed fuel injection timing, and the Bosch fuel system was tuned, providing more fuel pressure and additional performance. High Output ISB had slightly more power (+10hp) and torque (+45 lb-ft) and was being offered with only an NV5600 six-speed manual transmission. In 2001-2002 model year was a standard output and a high output ISB Cummins engines versions. The Common Rail injection increased power and torque and noticeably reduced engine noise compared to the previous 24-valve Cummins engines. The next step of ISB evolution was in 2003 when the engine was upgraded to a Bosch high-pressure Common Rail fuel injection system. The 24v engine had an aluminum intake manifold, new single-piece red or silver aluminum valve cover for the most comfortable and faster access to the engine components for servicing. Now the ISB engines use electronically controlled fuel systems (Robert Bosch GmbH) and a rotary type Bosch VP44 Electronic Fuel Injection Pump. One of the most recognizable differences is a 24 valve cast iron cylinder head (but still is OHV valvetrain). The ISB engine featured a multi-valve pushrod engine design.

The camshaft is installed inside the block. The ISB has forged steel connecting rods, an assembled camshaft, and aluminum pistons featured a symmetrical combustion bowl. It has an identical bore size and piston stroke compared to the 6BT.

2003 5.9 cummins engine serial number location