How to maintain your diesel engine

What are diesel engines?

First off, let's talk about diesels themselves. In case you didn't know, diesel engines are special types of internal combustion engines – which means they work by burning fuel inside of them – but what makes them different from other types of engines is that instead of using spark plugs or an electric current to ignite their fuel mixture as gasoline engines usually do, diesel engines use high compression to ignite the mixture in their cylinders. This difference comes with benefits and drawbacks, but if you know what they are, then you can make sure that your diesel engine stays in good condition for as long as possible.

How does a diesel engine work?

A diesel engine is an internal combustion engine that takes in air, compresses it and injects fuel into the compressed air. The heat of the compressed air ignites the fuel without the need for a spark plug like in a gasoline engine.

The combustion cycle is a repetitive four-step process:

The piston moves downward to draw in air.

The piston moves upward to compress the air in the fuel cylinder. Before reaching the top dead center, diesel is injected into the cylinder for combustion.

The piston descends again and the intake and exhaust valves close.

The piston forces the burned fuel out of the cylinder as exhaust gas.

Since a diesel engine only compresses air, its compression ratio is much higher than a gasoline engine, resulting in better efficiency.

What makes them different from gasoline engines?

Diesel engines typically have more torque than gasoline-powered engines, which means that they're able to produce more power at low speeds because the diesel fuel contains a lot of energy that doesn't get used up until it is needed by the vehicle or equipment that's operating under its power. This also means that diesel isn't very good at producing speed very quickly, so when revving your engine during gear changes to try and "match RPMs" before changing, this is usually a fruitless endeavor with diesel engines.

Common diesel engine problems

Failure to keep up with routine servicing. Neglecting oil and filter changes and fluid analysis doesn’t help you take care of your engine.

Overheating. Diesel engines run hotter than gas motors, which means the radiator is subject to higher temperatures. Proper cooling system maintenance is important. Don’t neglect your coolant as it will turn acidic over time, which hurts the engine.

Filthy filters. If you aren’t replacing the diesel filter regularly, it can “choke” your engine. This forces the engine to use more fuel to get power and acceleration and wears the engine down. You’ll know to check your filter when you notice weak acceleration or decreased engine power.

If you have an older diesel engine, be sure to empty the water separator to avoid leaks or moisture residue that can damage the engine. You’ll also want to let the engine reach the proper operating temperature to get efficiency. 

With new diesel engines, don’t forgo oil additives. Since these engines create a lot of heat and water residue, they can help to enhance engine lubrication with fuel additives. In winter, you’ll want to use winterization additives to prevent fuel clogs and reduce efficiency.

Diesel engine maintenance checklist：

Change oil and filters regularly.

Check and preserve water control components.

Keep water out of the fuel tank.

Maintain fuel injectors.

Check the alternator, radiator, compressor, and condenser mountings for looseness or cracks.

Check the vibration damper for cracks, bulges, shifting, or damage.

Watch out for unusual sounds and basic warning signs that indicate the need for repairs, such as fuel contamination, oil oxidation, or a black exhaust problem.

How to extend the service time of diesel engines:

Choose the right fuel. Use the best quality you can afford and fill the tank instead of just using a few liters.

Allow the engine to cool after each trip. Putting it into neutral when you get to the last stop will help keep the turbo in top condition.

Maintain a moderate revolutions per minute (RPM). Prevents damage to the engine and protects the transmission from vibration.

Keep your diesel filter properly clean.