How To Troubleshoot Engine Problems in Commercial Trucks

Since the engine is a critical part of any vehicle, it is always a great idea to make sure everything runs smoothly. If you are out on the road and notice your vehicle acting strangely, there are a few signs that will let you know if there is a problem with the engine. Usually, engine problems are not as scary as they seem. Most of the time, one problem will cause a plethora of symptoms that are easy to fix. Using the tips below, you can learn how to troubleshoot engine problems in commercial trucks.

Starting the Engine

One of the most noticeable signs of an engine problem is when the vehicle is either hard to start or will not start at all. There are a few issues that could cause this symptom. The first problem is clogged fuel filters. If dirt and other debris clog the fuel filter, it prevents the necessary amount of fuel from reaching the engine. After a long and bumpy ride, the connections to the starter can become loose. Remember to ensure that everything is connected correctly. Also, the batteries should be inspected as well to make sure they are operating properly.


An overheating engine is dangerous because it not only damages the engine, but it also harms other components of the vehicle, such as the pistons, crankshaft, and more. If you notice the engine overheating, the first step you need to do is stop driving and turn the engine off so it can cool down. Then, you can check the radiator for any airflow blockages. Usually, the failure of the cooling system causes an overheating engine. Sometimes, the cooling system is working but cannot keep up with the hot temperature outside, especially in the summer. If this happens, then you should gear down while driving to make it easier on the vehicle.

Colored Smoke

An excessive amount of smoke from any vehicle is rarely a good sign. You can diagnose the issue depending on the different colors of the smoke. For instance, dirty air filters or an insufficient fuel supply are both issues that cause black smoke. Weak engine compression is a common cause of white smoke, and worn valves, cylinders, and piston rings produce blue smoke.

Power Problems

Another sign to remember while learning how to troubleshoot engine problems in commercial trucks is a decrease in power. If you notice it is more difficult for the truck to drive up a steep hill or start in the morning, this is typically an indicator of a blockage somewhere in the engine. A clogged fuel system, dirty fuel filters, and broken fuel injectors are all common causes of power problems.

Sitting Oil

After sitting out in the parking lot for a while, the oil in the truck begins to thin out and acquire air bubbles. While this may not seem like a big deal, the thin oil can cause friction and rust, and both can cause extreme damage to many parts of the engine. Over time, the oxygenated oil can turn into a thick, unpleasant sludge that clogs up the engine. To avoid these issues, be sure to turn on the vehicle regularly, especially if it has been sitting in the parking lot for a long time.

Unusual Noise

Diesel engines are loud, but any unusual sounds tend to stand out. If you hear a knocking sound or if the regular noise from the engine becomes inconsistent, that is usually an indication of an engine issue. Since it is hard to determine the issue by sound alone, you may need to do a bit of inspecting to find the problem. If you are having problems with the oil, this could cause noise in the engine. Since the friction increases with the thin oil mentioned above, the noise emitted from the engine also increases. Also, engine bearings that suffer from wear and tear can cause a distinct knocking noise that is easy to identify.


Water is one of your engine’s worst enemies. Humidity in the fuel lines causes all kinds of problems, such as bacteria in your fuel tank, rusting the metal components of the engine and creating rust particles that clog fuel filters. The best way to prevent these problems is to be aware. For example, on any rainy days, make sure that all openings to the fuel tank are covered, especially when you stop to refuel.

Fuel Contamination

Unfortunately, it is very easy for diesel fuel to become contaminated. Glycol, debris, dirt, and more are all contaminants that cause engine problems. These tend to sneak into the fuel through broken seals and caps, and even occur in stored fuel that sits in a container for a long period of time. To avoid damaging the fuel pump, make sure the fuel you put in your vehicle is clean.

Additional Issues

Even though it can be tempting to ignore that check-engine light, even the smallest problems with the engine tend to snowball into larger issues. For example, an unresolved engine issue causes wear and tear on the entire vehicle. The breaks may begin to malfunction, the accelerator, and other aspects of the vehicle due to the engine issues. For this reason, it is important to fix any engine problems as soon as possible so you can drive safely.

Regular Maintenance

The best way to fix engine problems is to prevent them. Regular maintenance will protect your vehicle and keep the engine in pristine condition. Changing out worn parts, consistent inspections, and making sure the vehicle runs smoothly are all parts of regular maintenance. For your vehicles, it is a great idea to keep a few diesel engine overhaul kits on hand so you always have access to vital replacement parts.

To summarize, the engine issue signs to remember are difficulty starting the engine, overheating, colored smoke, power problems, friction, and rust caused by oil, unusual noises, humidity, fuel contamination, and additional issues. If you notice any of these symptoms in your vehicle, be sure to inspect your engine without delay.How To Troubleshoot Engine Problems in Commercial Trucks

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