Unlike the automotive industry, heavy duty diesel engines do not use the Make-Model-Year formula that an automotive engine does. Instead, heavy duty diesel engines rely on an Engine Serial Number (ESN) and/or arrangement & build or list numbers. These numbers are incredibly important in getting the correct parts for heavy duty diesel engines. An engine that’s a particular model is not guaranteed to be exactly the same as another engine of that same model. For example, Caterpillar engines are used in a variety of equipment each application having its own specific makeup of parts. From simple differences such as engine mounting configurations, exhaust and cooling configurations to more complex things such as piston design, injection pump ratings and turbochargers. To keep track of all of this, in addition to an ESN Caterpillar uses an Arrangement Number. This information is typically found on a tag fixed to the engine or stamped into the block.



In the case of Perkins engines, a List Number is used.

In any case these numbers tell your parts professionals at Construction Parts HQ exactly what parts were used to build that specific engine right down to the last nut and bolt.


Engine serial numbers, arrangement numbers or build numbers are a surefire way to get a list of the exact parts that are in your engine. In addition to these numbers it is good practice to also have the Make, model and serial number handy of the piece of equipment the engine is used in.


When you’re working on your engine and you go to order parts, the parts professionals at Construction Parts HQ will need to know your ESN and Arrangement Number or List Number if applicable so we can get the appropriate list of parts for your specific engine. This will guarantee that we get you the right parts the first time. The only additional thing we will need to know is if you have undersize bearings, or have otherwise changed the engine specifications, as that would not be accounted for in the ESN.

So, to get your order processed without delays, be sure to have that information handy when you order.

We’re Here to Help

Should you have any questions regarding the location of your ESN, identifying your engine or questions regarding parts, be sure to give us a call at 315-559-4992 OR you can use the “contact us” form on our home page.