
We know that when you’re looking for parts for your Caterpillar engine, you don’t want to waste time and money on the wrong parts. That’s why it’s important to know your diesel engine’s serial number. It helps us ensure you’re getting exactly what you need the first time you order.

So you might be wondering where the ESN is located on CAT engines. In this post, we’re going through common places to find this information!
Finding Your Caterpillar ESN
When looking for your engine serial number, the data plate is a good place to start. This is where most ESNs can be found.
Often, this plate is on the driver side of the valve cover, but it’s important to note that not all engines are consistent. The data plate can be found in different places depending on the model type.
Caterpillar, though, is usually pretty consistent, so the driver side valve cover is a good place to start.
What’s the Format of Your Caterpillar ESN?
We know it can sometimes be tricky to locate an ESN, especially if you’re not familiar with the format a manufacturer uses. That’s why sometimes customers will give us part numbers, casting numbers, or VINs, because it’s not clear what they should be looking for.
Fortunately, all Caterpillar ESNs are similarly formatted, making them easily identifiable. You’re looking for an ESN with a three number/letter prefix, followed by seven digits.
What Do the Prefixes Mean?
These prefixes all correspond to a specific model, and, in most cases, to a subset of that model.
It’s common practice to refer to popular models by their prefix, rather than the name of the model itself. This is true of the 6NZ, for example, which is a common prefix for a single-turbo C15.
There are some prefixes with bad reputations, like the oft-criticized MBN, or Bridge motor, as it was the bridge between the mechanical C15 to the electronic C15 ACERT.
What are the ESN Prefixes By Model?
3406:
- 92U
3406B:
- 2EK
- 3ZJ
- 4CK
- 4MG
- 5KJ
- 7FB
- 8TC
3406C:
- 3ZJ
- 4CK
- 5KJ
- 8PN
3406E:
- 1LW
- 2WS
- 5DS
- 5EK
- 6TS
C7:
- KAL
- C7S
C12:
- 1YN
- 2KS
- 8YF
- 9NS
- 9SM
- CPD
- GEP
- MBL
- TME
C15 and C15 ACERT:
- 6NZ
- 9NZ
- B5R
- BXS
- EGH
- JEP
- KRA
- MBN
- MXS
- NXS
- RKS
- SDP
- TRB
C16:
- 7CZ
Is My Caterpillar ESN Really That Important to Shop?
It might be a hassle to find, but your engine serial number is actually really important to have when you’re ordering parts. It helps us guarantee that you’re getting the right parts for your engine, because we’re able to look up and see what components your engine was originally built with.
Shopping With Highway & Heavy Parts
On some of our product pages, we have a box under the price with available options. One of these options is a field for your engine serial number.
You can complete your order without inputting your ESN, but we’ll give you a call asking for it before we can process the order. We want to make sure you’re getting the right parts the first time!
Highway & Heavy Parts Can Help With Your Caterpillar Diesel Engine Needs!
We have a wide selection of components for your CAT engine, and we can get those parts to you fast!
We have ASE Certified technicians on staff who can help diagnose what’s going on with your diesel engine and help you get the right parts for the job!
You’ll be getting fast and accurate quotes, and you can call us or shop online. And you can rest easy knowing our parts are covered by industry leading warranties.
From diagnosis through delivery, we’re Highway & Heavy Parts!
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