Tips To Maximize Your Diesel Engine Life

April 7, 2021

Engines receive the most wear and tear given all the moving pieces and fluids. Properly maintaining your diesel engine can significantly reduce your long-term maintenance costs.

Diesel engine components
Diesel engine components

Your machine's diesel engine is likely the most expensive item to replace, as well as the biggest driver of your parts and labor costs over the service life. Engines are very complicated, have hundreds of moving parts, receive a lot of wear and tear, and are exposed to extreme fluctuations.

When you think about it, an engine is a device that transforms diesel explosions into controlled mechanical force and energy. This is not easy — it requires exposure to high temperatures and pressure, countless moving pieces and a range of fluids.

Moving pieces cause friction, and friction over time wears down parts. These parts need to be replaced at regular service intervals determined by use and time. In addition, the fluids that help these parts function (such as oil, coolant, etc) need to be replaced and monitored. It is important to keep your engine healthy and in proper working condition. Engine service is similar to the age-old saying "A stitch in time saves nine".

What Are The Diesel Engine Components?

Most diesel engines systems include:

  • Fuel system routes diesel from the fuel tank to the engine cylinders to produce the combustion and release energy the stored as carbon (diesel fuel). The fuel generally flows through multiple stages: fuel tank ➜ water separator ➜ feed pump ➜ filter ➜ injection pump ➜ injector nozzle ➜ cylinder.

    Water, sediment and impurities can be present in the fuel and fuel tank — these imperfections can wreak havoc on your diesel engine if they make their way past filters and into the injector and cylinder.

    Using a fuel stabilizer helps prevent fuel from gelling in cold temperatures. Also, it adds additional lubricants to the fuel to help the entire system function better. New low-emission regulations reduced the number of natural lubricants in the fuel system (i.e. sulfur), so the need for added lubricants is higher than it had been in the past.

    The fuel filter must be checked regularly, and cleaned if sediment builds up. Check for the presence of water — condensation from natural weather fluctuations can cause a buildup of water in your fuel tank. Water can cause serious damage to your injector system if it makes it past the water separator.

  • Lubrication system helps reduce the friction of moving parts and prevent wear and tear. Think about chalk on a chalkboard — as you write a little bit of the chalk rubs off onto the chalkboard until the chalk stick finally disappears. This phenomenon happens due to friction. If you were to make your chalk wet with water or oil, it would not write anything because the lubricant is doing its job of separating the two hard components (chalk and chalkboard).

    Lubricants help separate your engine components (typically made of metal, rubber, etc) from each other and help them move and glide without wearing each other down.

    The most important and well-known lubricant is oil. Oil is stored in its own tank and pumped through a strainer and filter. It makes its way to the main gallery and then flows to the main bearings. After it lubricates the main bearings it makes its way to a hole to the pin. It then travels to the piston pin and lubricates the piston rings.

  • Cooling system helps transfer heat energy produced by the internal combustion process. Cooling mediums are typically fluid or air. Fluids have the ability to absorb more heat energy. The cooling medium absorbs heat in one area, then travels to a lower temperature area to dissipate the heat. A cooling system is required to cool oil and the engine parts.

  • Electrical system generally includes the starter motor, alternator and battery.

    The starter motor draws energy from the battery to start the engine movement.

    The alternator's main function is to charge the battery. It takes energy from the motor to recharge the battery.

    The battery stores energy when the motor is off and releases energy for the starter motor and other electrical components.

  • Air intake system transfers outside air to the engine. Air is necessary for the combustion process to occur. Oxygen is critical for the ignition process (think about a campfire or fireplace). Similar to the fuel system, air must be cleaned and filtered before it is exposed to the core engine components.

    Generally, air follows this path: External source ➜ cleaner ➜ turbo (not all engines have a turbo) ➜ intake manifold ➜ inlet port ➜ inlet valve ➜ cylinder bore.

    The air must be cleaned with filters, otherwise, sediment and debris can build up inside the engine over time. These filters must be replaced at regular intervals.

    Turbochargers compress air from the air filter, and they help improve the fuel efficiency of the engine.

  • Exhaust system removes the combustion byproducts from the engine. Generally, the path follows: Cylinder bore ➜ exhaust valve ➜ exhaust port ➜ exhaust manifold ➜ turbocharger (optional) ➜ muffler.

    Exhaust systems help "clear the way" so new fuel and clean air can move into the cylinder bore.

    The air leaving the exhaust system is often at a higher pressure and temperature than the ambient atmospheric air — this is what causes the noise.

The Importance Of Maintenance

Like most things in life — you get what you pay for. With a diesel engine, your payment is your attention and regular care of the engine. If you take good care of your diesel engine you will likely get a good performing component with minimal surprises and downtime.

Engines are complex, and with complexity comes the potential for problems to cascade. For instance, if Part A breaks and goes unfixed for some time, Part A can break Part B and Part C. Instead of one problem, you can end up with three or more. This is why it's crucial to fix issues as they arise. More importantly, it's important to try to prevent issues from arising ("preventative maintenance").

Generally, manufacturers will specify specific intervals based on time and use that components of the engine should be checked or replaced. It is extremely important to follow these guidelines and record the service intervals. These intervals are determined by years of performance history.

Manufacturers have large amounts of data regarding the performance of their machines. They can use statistics and data-based research to determine optimal service intervals to optimize the life of the machines.

Following manufacturer guidelines and servicing your machine at recommended intervals helps you maximize your resale value. Buyers want to know that you cared for your machine while you owned it. Make sure you keep your records (notes, as well as invoices) for proof.

The Importance Of Good Documentation

Keeping good documentation of service is important, especially if multiple people work on the machine or you plan on selling or transferring ownership at some point down the road.

Buyers will often look at the quality of the service records and adjust their offer prices accordingly. If you were offered two identical machines — one with fantastic service records and notes, and the other without... you would almost certainly pick the one with good documentation. Good documentation signals that the prior owner(s) cared for and paid attention to service.

Proper Parts & Fluids Make A Difference

Chuck steak and rib-eye steak are both beef cuts. One is a lot better than the other. There are meals and events when you should serve chuck steak, and there are other occasions when it's better to go with the rib eye.

Obviously, if money were no issue then we would pick rib eye every time. The same concept can apply to parts and fluids.

Saving a few bucks on parts and fluids may seem smart at the time, but it can turn into a pricey proposition if those items cause engine failure or reduce the expected service life of the engine. Do your research if you plan on using non-branded parts or fluids. Saving $20 today could cost you $2,000+ six months from now.

You should always follow manufacturer specifications for parts and fluids if your machine is under warranty. Not following the directions can void your manufacturer warranty.

Now should you pick rib eye every time? It depends on your budget, risk tolerance and the occasion. If your engine is under warranty then choosing a rib eye is a lot better than losing your insurance coverage and risking your house burning down.

Lookout For Red Flags

Engines often show symptoms of problems or stress. Keep a lookout for the following:

Hard Starts: Stalling or trouble starting the engine signals something is wrong.

Issues Accelerating / Loss of Power: This suggests something is either broken or needs to be replaced (filters, or other parts). Your engine's filters are like a breathing person with a mask — if the mask gets too dirty it makes it harder to breathe and the person will have a difficult time running or moving quickly.

Exhaust Color or Smell Change: This suggests that a foreign fluid (other than diesel) has made its way into your injection system and is changing the exhaust. This needs to be addressed immediately. Foreign fluids such as water can cause serious damage to your engine's injection system.


If you take care of your diesel engine, then it will take care of you. Follow your manufacturer's suggestions, service your engine at the recommended time and use intervals, keep good documentation, and look out for red flags. By following these steps you will best position yourself to keep your engine healthy.


Components of an internal combustion engine

Diesel engine class 101

Dissecting a diesel engine

How an engine works

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