How to check Caterpillar serial number?
ENGINE SERIAL NUMBER: Locate the serial number of your engine. This information can typically be found on the engine data plate, located on the left side by the injection pump/rocker arm cover. Engine serial numbers (ESN) are also stamped on the engine block. Caterpillar Engine Serial Number Identification All Caterpillar ESNs have a similar format. They all begin with a three number/letter prefix, followed by 7 digits. The prefixes will correspond to a particular model. For example, prefixes of 1LW, 2WS, 5DS, 5EK, and 6TS indicate that the engine is a 3406E.