The Main Parts of a Diesel Engine

Diesel engines are incredible because they’re fuel-efficient and are perfect for heavy-duty vehicles. For this reason, many trucking manufacturers have decided to use diesel engines for their trucking fleets. However, in order to understand the true power behind a diesel engine, truckers need to understand the main parts of a diesel engine, as well. This article will overview some of those parts and explain their functions, so people know what to do in case of emergency.

Before we discuss the parts of a diesel engine, we should talk about the differences between a remanufactured and rebuilt engine. ATL Diesel believes that remanufactured engines are best because they’re like giving old parts new life at half the cost. On the other hand, if you try to rebuild the engine by yourself, things may go wrong, and you can even get hurt in the process. So, keep this in mind as you read about the parts of a diesel engine. It’s always better to get them remanufactured than doing something wrong on your own.

Head Gasket

A head gasket lies between the engine block and cylinder heads of a diesel engine. First and foremost, the component stops liquids from leaking onto the cylinder heads. If the cylinder heads get wet, they won’t be able to provide the right fuel and air mixture to start. Head gaskets are also prone to warping because they see the most extreme changes in temperatures—cooler temperatures from the coolant system and warm temperatures from combustion. So, drivers must watch out for potential signs of failure.

Fuel Injectors

Diesel engines operate differently from other traditional engines. They need a fuel and air mixture to start, as well as a tremendous amount of heat. For this reason, fuel injectors are one of the most important parts of a diesel engine. These components release diesel gas into the combustion chamber where it mixes with air, and the ignition starts the car. However, this begs this question: where does the fuel and air mixture go after the combustion chamber?

Camshaft and Crankshaft

The camshaft, duh! The camshaft is located near the top of the engine. This part allows fuel and air to come in and releases other exhaust smoke outward. The camshaft opens and closes valves that allow for combustion to occur. So, where does the crankshaft come into play? The two parts essentially work together!

The crankshaft is one of the most intricate parts of a diesel engine. This piece operates on a rotary movement, almost like a bicycle. This sentiment is true for the camshaft, as well. The crankshaft remains closed, holding down the air and fuel mixture needed for combustion until sensors tell them it’s time to open, consequently making the automobile start.

The Crankcase

The crankcase surrounds the crankshaft, enclosing it while it rotates. The crankcase bears the weight of the crankshaft since this part is incredibly heavy. This component also directs any excess oil to the oil pan, which is exactly what it sounds like. Oil pans collect the additional lubricant and oil that’s not needed for combustion. Some larger automobiles have several oil pans, while smaller vehicles have just one.


Perhaps the coolest part of a diesel engine is the flywheel. The flywheel is located on the end of the crankshaft. This part does the following things:

  • Minimizes noise when the crankshaft rotates.
  • Minimizes vibration.
  • Some flywheels have teeth-like edges to aid in the rotation when needed.

Cylinder Heads

If you couldn’t tell by now, the fuel and air mixture needed for combustion is incredibly important to a diesel engine. If the engine doesn’t receive the appropriate mixture, it won’t start correctly. Luckily, cylinder heads are there to help. These cylinders sit at the top of the engine block and prevent droplets of the air and fuel mixture from getting into the combustion chamber.

Cylinder heads also do their best to stop engines from overheating. When an engine starts, it gets incredibly warm. Yet, at the same time, it releases coolant to ensure it doesn’t overheat. The coolant absorbs the heat from combustion and moves toward the radiator inlet. As long as the coolant isn’t too hot, the thermostat of the car will allow it to pass through the cylinder heads. Larger vehicles have more cylinder heads than smaller vehicles. Therefore, they have more passageways for coolant to flow through.

Exhaust System

Another main part of the diesel engine is the exhaust system. The exhaust system is essential because it gets rid of any unwanted materials that do not belong in the engine. A previous blog posts discuss the different colors you may see from your exhaust system and what they mean. Below is a brief summary of these colors and meanings:

  • Black smoke: Black smoke indicates that there’s a faulty fuel injector pump and that the engine isn’t getting the proper fuel and air mixture it needs to run properly.
  • Blue smoke: Blue smoke indicates that you’re burning engine oil. This can be a problem because, even though your engine technically has enough fuel to run, it doesn’t think it does.
  • White smoke: White smoke means that coolant is leaking out of your engine, which may cause it to overheat.

Every driver should know the main parts of a diesel engine in case something goes wrong. The more someone knows about an engine, the less likely it is that problems will occur. If worse comes to worst and you do need new engine parts, look no further than ATL Diesel. We have remanufactured diesel engine parts for sale that are cheaper than newer counterparts, and they work just as well.

There are more benefits of buying remanufactured diesel engine parts. For example, they are better for the environment. Instead of sitting in a landfill for years on end, we take these components and give them a fresh face so they don’t just rot away. Don’t forget—we offer them at a discounted price, so you don’t have to pay as much when the time comes for replacement parts. So, as you can see, there are many advantages to using remanufactured parts. As long as you work with a trusted manufacturer, there’s little that can go wrong.

The Main Parts of a Diesel Engine