The most common problem with the 24-valve Cummins diesel engine is the 53 block problem, and less common problems include a bad crankshaft position sensor, a weak lift pump, intermittent high-engine idle and excessive engine noise. Owners also report a buzzing noise from the accelerator pedal when using cruise control.
The 53 block problem occurs in 1999 to 2001 24-valve Cummins engines. A Brazilian company manufactured these engine blocks, and the thin water walls are prone to cracking. Frequent towing, running the engine cold and overheating accelerate the problem. The cracks ultimately result in the engine losing coolant. These engines have "53" stamped on the side of the engine block, and although some 12-valve Cummins engines have 53 blocks, the 12-valve engines do not crack like the 24-valve engines.