The Cummins engine serial number is stamped on the engine dataplate and also on a machined pad on the right-hand side of the engine block near the front. The CPL (Control Parts List) number appears on the dataplate above the serial number — it is a three or four-digit number that identifies the exact specification build of your engine. For ISX and X15 engines, the CPL is essential for identifying which fuel system, turbocharger, and aftertreatment configuration your engine uses, as these change across CPL revisions. Always provide both the serial number and CPL when ordering parts.

Generally no. While the ISB 5.9 and ISB 6.7 share a common engine family, the 6.7L engine has a longer stroke and uses different pistons, liners, crankshaft, and connecting rods. Many gasket dimensions differ, and the fuel system components — particularly injectors and fuel pumps are not interchangeable between 5.9 and 6.7L applications or between mechanical injection and common rail generations. Always verify by serial number and CPL, not by displacement alone.

Yes. We source Cummins marine engine parts QSB5.9-M, QSB6.7-M, QSC8.3-M, QSL9-M, QSM11-M, and QSX15-M with awareness of marine-specific cooling, corrosion, and sensor configurations. Marine Cummins parts orders require the marine engine serial number, which differs from the base industrial engine serial number. Call (281) 446-1230 with your marine engine serial number for parts availability.

We source EGR valve assemblies and EGR coolers for ISM, ISX, ISL, and ISB EPA07-compliant engines; DPF filter elements and DOC assemblies for CM2150 and CM2250 aftertreatment systems; and SCR catalyst assemblies and DEF dosing system components for CM2250 and CM2350 (X15) applications. Aftertreatment system parts require the engine serial number and CM code to confirm the correct configuration. Call us with this information for immediate availability check.

Yes. Our Humble, TX facility performs Cummins ISX, ISX15, and X15 engine overhauls both in-frame and out-of-frame using our in-house machine shop for boring, honing, crankshaft grinding, and head reconditioning. We perform compression testing, CPL-verified parts specification, and a structured run-in procedure on every rebuilt engine. Call (281) 446-1230 to discuss your ISX rebuild project.