Caterpillar Engine Identification

by Jeff Woodward
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Caterpillar Inc. is one of the largest diesel engine manufacturers in the world. Popular on-highway engines such as the 3406E and the C series engines have made Caterpillar a top choice among truck manufacturers for use in their vehicles. All Caterpillar engines are shipped from the factory painted yellow, making them one of the most recognizable engines in the automotive industry.

Engine Color

One of the easiest ways to determine if an engine is a Caterpillar or not is by its color. All Cat engines are shipped from production painted yellow regardless if the engine is destined for earth moving equipment or on-highway truck use. Even after years of use, the engine will still have hints of yellow-patched paint. The bright yellow is a clear indicator to a technician or vehicle owner that the engine is a Caterpillar.

Mechanical or Electronic Engines

Mechanical engines were used before the development of the ECM, or Electronic Control Module. Mechanical engines use fuel nozzles and governors, whereas an electronic engine will have fuel injectors and either an injection pump or a fuel transfer pump. The ECM will be present on the driver’s side of the engine. Electronic engines will also have a series of wiring harnesses plugged between the engine ECM and the vehicle chassis.

Model 3406 Engine

The Caterpillar 3406 engine was a popular choice for truck use before the development of the C series engines. The 3406 was available as a mechanical or electronic engine. The ending designator after the model 3406 (E for electronic or B for mechanical) indicates to the owner what type of Caterpillar engine they have. The engine dataplate is located on the driver's side of the valve cover.

Model C series Engines

The C series engine was developed by Caterpillar to comply with diesel emission laws. They are electronic engines with ACERT technology capable of reducing carbon emissions. Some models such as the C15 are built with twin turbochargers. An engine data plate is located on the driver’s side of the valve cover consisting of engine model and serial numbers.

Model 3126 Engine

The 3126 series engine was used by Caterpillar in both marine and on-highway vehicles during the 1980s. The 3126 is a six cylinder mechanical engine consisting of three valves per cylinder. Caterpillar stopped production of the 3126 due to emission standards enacted by various governments around the world. The 3126 has an engine data plate of the left side of the valve cover for easy identification

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