Common Problems Faced by Diesel Engines
Common Problems Faced by Diesel Engines

Most commonly repaired diesel engine issues

It is the right time to own a light commercial vehicle for your small business, and if would be even better if you have your vehicle powered by a diesel engine. Because diesel is cheaper than any other fuel across the board and it gives more mileage at the same time. The diesel engine is an economical choice and at the same time production of some extra power is always a good thing. It is also important to mention here that diesel engines are not unbeatable like any other vehicles on the market, they have their own issues and problems.

If a diesel engine is not properly maintained or serviced, it can cause several issues either internal problems or the external issues. An improperly serviced diesel engine can potentially cause issues with the internal combustion system and can easily ruin the entire system. This may result in having to get the whole unit replaced by a reconditioned or used engine.

Following are some of the most commonly reported and repaired problems faced by diesel engines.

1. Oxidized Oil

There were many issues reported and repaired in the past term on our member garages and the engine re-conditioners, but we have selected the most ignored but equally dangerous 11 problems that diesel engines usually face. Engine oil oxidization always saw sitting at the top spot in this race of problem and issues.

Engine oil oxidization or even the transmission oil oxidization usually occurs when diesel engines remain at rest for more than a season or even during the season change times. The oxidization issues arise when air gets into the oil sumps or oil storage and remains in there for more than a season. The air in the oil sumps or oil storage creates bubbles in the oil and these air bubbles further interfere with the lubrication process and play a vital role to ruin everything that needs lubrication. These air pockets or air bubbles cause rust and friction by rupturing the thin oil layers between the moving parts. Results arise in the form of damaged and faltering engine or engine components failure.

In case of oil oxidization, technically, oil is not dirty or even not completed its life, but its chemistry has been changed, and the composition of the chemicals has been destroyed by the air and chemical reactions. Now it needs to be changed at first convenience, most probably before you use your vehicle again.

2. Humidity Reactions

As mentioned in the first problem where the engine oil oxidization can cause harmful results to the engine, water is also equally dangerous if it finds its way into the combustion system. Water in any part of the engine where it shouldn’t be there can create serious issues and problems. Water proves to be one of the most dangerous elements when it mixes with the lubricants. Water contaminates the engine oil and creates a separate layer along with oil layers between the parts, and it causes serious rusts between the parts.

The question is how water can enter into the system? It is not that technical but an easy thing. If a diesel-powered vehicle is parked for too long in a humid and precipitous environment, the hydration starts working and this way water enters into the oil storage and can cause the engine to knock badly. Water in the oil attacks the additives and kill the composition of chemicals and further increases the oxidization risk factor. When it enters into the main lubrication process, it definitely leads to the severe problems and massive damages e.g. crankshaft failure.

3. Black Exhaust

This is what you can say the habit of a diesel engine that it exhibits more excessive smoke than other traditional vehicles. If you are driving behind any big lorry with a diesel engine, after some distance you will definitely feel some black suits covering your windscreen and front parts of the vehicle. You will start feeling an unpleasant odor soon, and this can stink up the cabin. Most of the times, hard to breathe inside of your cabin even you are behind a diesel vehicle.

Although this is nothing to mention that the condition will likely be slapped with fines and charges for ignoring the clean air ordinance but do remember that the diesel engines are black by birth.

The excessive black smoke on the exhaust pipes usually causes the bad and imbalanced air to fuel mixture ratios. Technically, diesel engines emit black smoke when they eat more fuel than there is not enough air available in the system. The reasons for decreased air in the system or increased fuel in the system can be many, e.g. a faulty injector, diesel pump, air filter and EGR Valves can be the causes. On the other hand, if you have a turbocharged engine, a faulty turbocharger can also be the root cause of the black smoke.

4. Hard Starting

Diesel engines are not like the petrol engines as they do not use any spark ignition system or plugs or electric wiring to start the combustion. They simply use the air compression to burn the fuel. In the cold season, usually, diesel engines face difficult starting times and could not start in a normal flow as they do in warmer conditions. Usually, this happens due to low compression or the fuel delivery issues. Normally, diesel engines take a bit longer cranking while starting up in the winter season, which is according to the experts, absolutely normal. But at the same time, if the diesel engine is taking even longer on cranking and not igniting up, this situation indicates some serious issues. Now it is time to get things checked by a professional engine mechanic to keep the things flowing safe and smooth. When a diesel engine starts taking longer cranking times on startup, it starts eating the battery power more swiftly as the starter motor needs battery power to crank the engine. Keep an eye on your battery pack if it gives sufficient power to the starter motor.

5. Lack of Power

You would be amazed to know that diesel engines are more powerful and torquey motors than the petrol engines. This is the reason why diesel engines used all over the heavy machinery and in your light commercial Ford Transit 2.4 liter TDI van. But everything goes faded when a driver feels that its diesel engine is not producing enough power. Usually, the lack of power issues arises and noticed on the starting of the engine or at the peak accelerations. A sudden dip in the power delivery usually causes by the bad or dirty fuel filters, blocked or clogged fuel delivery lines, throttle linkage, lower or excessive lubrication, bad or faulty fuel injectors and the fuel pump. Failing to get enough or up to the mark power could be caused by any of the stated components.

6. Failing Lead-Acid Storage Batteries

Yes, this is true that the lead-acid batteries are the most useful components in a diesel engine and they play a vital role in starting the engine. Lead acid batteries give power to the starter motor, and the electric starter motor cranks the engine through flywheel to ignite the engine. If the battery pack malfunctions, it doesn’t provide enough power to the starter motor. Resultantly, the starter motor fails to start the engine. Improper engine cranking causes imbalanced compression ratio that influences the engine starting system badly. Thus the lead-acid batteries are also in the top repairs.

7. Defective Glow Plug

Diesel engines are different from petrol engines, and they also have different ignition procedure. Petrol engines use ignition coils and spark plugs to ignite the system, however, in the diesel engines, the system uses the air compression method to ignite the engine. They do not have any source of spark to ignite the fuel and air mixture in the cylinders. The diesel engines use glow plugs to ignite the air and fuel mixture through high resistance heating elements. These elements work like the heating elements in the stove coils or in the toasters. When glow plugs gone badly, they left the diesel engines irresponsive and almost impossible to start especially in the cold weather.

8. Contaminated Fuel

Diesel is relatively a viscous fuel than petrol or any other fuels, e.g., ethanol. Light fuels, e.g., petrol or ethanol hardly become contaminated, but on the other hand, diesel because of being more viscous easily becomes contaminate and cause problems in the diesel engines.

There are different types of contaminations usually found in the diesel fuel but most commonly reported four contaminations include, glycol, dilution, soot, and water. These four fuel contaminations are very dangerous to the engine, and if any of these contaminants penetrate into the engine fuel pump or diesel injectors, they can damage them seriously and lead to major disruptions.

9. Higher Compression Ratio

Normally, an average diesel engine has a compression ratio of 20:1, however, an average petrol engine has a compression ratio of 8:1. This massive difference between compression ratios makes the diesel engine more powerful, ultra-efficient, smooth and torquey at the same time. At the same time, this situation can also lead to the problems, e.g., it can lead the engine to knock more than usual and undesirable fuel burning patterns. Ultra-high compression can also lead to the fuel injector issues. Diesel injectors are one of the costly and precision components and play a significant role in the power generation and efficiency of the engine.

10. Noise

It is a reality that the diesel engines are normally noisier than the petrol counterparts and noise from these engines can be something significant to identify the problems. The noise can be something significant to identify the issues with the engine at the same time. As we know that the diesel engines are louder than other engines by birth, but their sound always comes in a harmonious track. Which although louder than others but sounds pretty at the same time. If you notice any inconsistent or unusual soundtrack coming from the diesel engine, or you feel that the engine is knocking or something sounds like a rattle than these signs are the indications of any issues arising in the engine. It might be a sign of any problem with the diesel injectors, or there is something wrong with the compression balance. All these issues can easily reduce the power coming from the engine.

11. Wrong Weight Viscosity

Correct grade engine oil is one of the most important factors behind the performance of an engine, but in the case of diesel engines, this factor becomes even crucial. Bad grade oil in the diesel engines can create hard start problems because of incorrect weight viscosity of the engine oil lubrication. The oil viscosity in the diesel engine oils is relatively higher if compared to the petrol engines. It is observed that the majority of the drivers and vehicle owners choose incorrect engine oils with wrong viscosity ratios when replacing their vehicle oil. The first time people use high weight heavy viscosity oil for their engines and the next time they use single weight low viscosity oil for their engines and then forget to shift back on the multi-viscosity engine oil during the winter season. It simply cost them money, and they got their vehicle engine ruined and spoilt before the end of its actual life. So, it is always recommended that always use the multi-viscosity engine oils forever to avoid any risk of engine damage.

It is also recommended that when there is anything wrong with your diesel engine, it is the best solution to look into these 11 most common repairs to save money and time. Drivers can take good care of their vehicles by performing timely and routine maintenance of their vehicles. With the help of timely and routine maintenance, you can save your vehicle from big issues. It is also recommended that you must report all your engine issues to an expert mechanic who specializes in diesel engine care and maintenance.