One of the most important aspects of fleet management is reliability. Diesel truck reliability ensures that goods are transported and delivered promptly and provides managers with relative financial security as their drivers travel. Though every fleet manager regards regular maintenance as incredibly important, the demanding transportation requirements that this job entails may cause a diesel engine to suffer from extended use. If left unchecked, this can endanger your drivers and business alike. The mechanics here at Certified Diesel Solutions want to ensure that the trucks in your fleet are running as smoothly, safely, and efficiently as possible. That’s why we’ve compiled a list of some of the warning signs that accompany a possible diesel disaster, and how best to avoid, as well as fix, the possible issue at hand.

What Are Warning Signs of Diesel Engine Failure?

One of the key components that keep your diesel truck running is the engine. It is notably one of the most complex aspects of the machine and includes many moving parts that are incredibly delicate in nature. It includes such parts as the battery, the alternator, the transmission, and many more. Luckily, technology has advanced enough that your car or truck will usually alert you when one of these parts is not working the way it should, but there are other signs to pay attention to if you feel that your truck is not operating properly. 

Ignition Issues:

If your truck is having a difficult time starting, this is an obvious issue to be concerned with. This can occur for any number of reasons. One of the more common reasons that your truck won’t start is low compression. Low compression occurs in diesel engines when a key part of the engine, such as the valves, pistons, or camshaft. If any one of these parts is leaky or worn down, it can throw off the finely tuned diesel engine. Diesel engines rely on combustion power to operate properly. Because of this, air pressure is intensely important to the smooth inner workings of the engine. If one of the key engine components begins to leak air, it can prevent your vehicle from starting.

There are many different reasons why your diesel engine may have trouble starting. Vehicles can be incredibly sensitive to changes in weather or air pressure, or the fuel delivery system may be malfunctioning. The fuel used in diesel engines may even be growing bacteria that don’t allow for an operating engine. Another section of this article will outline possible reasons for a loss of engine power that include the alternator and transmission. Because the reasons for a faulty ignition seem rather endless, it is best to bring your truck in to be looked at by a mechanic if you are experiencing this issue.

Smoke Coming From Your Exhaust:

Smoke emitting from any vehicle is never a good sign, but especially not from your diesel truck. Several different kinds of smoke can be released if your truck is in desperate need of repair. Smoke can range in color, from blue to white, to black. Here is what each type of smoke can indicate:

  • Blue or Gray Smoke: Blue and gray-colored smoke usually indicates that your engine is burning oil. This is usually accompanied by a burnt oil smell when accelerating. If your oil light turns on, assume that the engine needs to be shut off immediately.
  • White Smoke: There are two main types of white diesel smoke to pay attention to. If thin, white smoke is emitting from your truck, this usually indicates condensation and should be nothing to worry about. However, if thicker smoke seems to be coming from underneath the hood of your truck or from your exhaust, this indicates that your engine is burning coolant. This can be caused by a blown gasket, a damaged cylinder head, or even a cracked engine block. Thick white smoke could also suggest that diesel fuel is passing through the engine without being burned. Either one of these issues is serious and should be looked at by a mechanic immediately
  • Black Smoke: This type of smoke is usually referred to as “rolling coal.” Though sometimes diesel truck owners can make modifications to their engines to purposely emit black smoke, if a large amount of unintended smoke escapes your exhaust, it could indicate a large problem. Possible causes for black smoke include incorrect air to fuel ratio, a worn turbocharger, too much carbon buildup in the combustion chamber, and much more.

No matter what color of smoke you see a trusted diesel mechanic is sure to know how best to address the situation at hand.

Poor Gas Mileage:

Another indicator of a possible diesel disaster is poor gas mileage. There is nothing more heartbreaking for a truck driver than watching that little needle fall to “empty” faster than it should. Diesel fuel is expensive and cannot be wasted. If the gas mileage on your vehicle is significantly worse than normal, you could have a large problem on your hands.

Poor gas mileage can indicate wear or dirt on the fuel injectors, misfiring spark plugs, or a faulty exhaust system. Any of these issues can lead to greater internal damages if not addressed properly and promptly.

Excessive Engine Noises:

Odd noises coming from inside your diesel engine are never a good sign. It’s any truck driver’s worst nightmare to be chugging down the highway and suddenly notice a cacophony of noises accompanying a once peaceful drive. Different sounds could indicate a variety of issues. Here are a few of the most common sounds to look out for when driving:

  • Clunking or Knocking: This could indicate that there is damage to the main or rod bearings within your engine. These bearings are connected to the pistons, meaning that when these bearings are worn or out of alignment, the pistons and other rods begin to knock against each other, creating this noise.
  • Rattling: This noise coming from your engine is usually caused by an air and fuel mixture that is ignited prematurely. It is called “pre-ignition” and can cause other types of damage to your vehicle. The other parts that can be affected by pre-ignition include the rods, pistons, and connecting valves that keep your engine running smoothly.
  • Timing Chain: The distinctive rattle of a chain can sometimes be heard coming from your diesel truck. This is related to your truck’s timing chain, which helps to ensure that the engine’s valves open and close at the proper time so that exhaust can be released. When it gets cold outside, this rattling can be louder and more aggressive, whereas when it’s hot, it is usually quieter. Usually, the timing chain can be easily tightened, but if this doesn’t stop the rattling, it could be time to replace the chain altogether.

Whatever the noise may be, it’s always good to get your diesel truck regularly looked at by a mechanic to ensure that these common problems don’t become more serious.

Possible Causes for Diesel Engine Power Loss:

With the strenuous use of your diesel engine, there are certain components that will be subject to wear and tear over time. Though this is the case, the power of this engine is vital. If you are noticing an issue with your power as you climb steep hills, or begin to notice various electrical failures, you could be experiencing the effects of a damaged alternator, a faulty transmission, or a worn turbocharger.

Alternator Concerns:

If you are experiencing significant power failure in your engine, it could be an indication of alternator failure. The alternator is the part of your engine that provides power to the battery, allowing it to function properly and keep all its electrical accessories in working order. If your alternator requires repairs, here are just a few of the key warning signs:

  • Stalling or Having Trouble Starting: If your engine regularly stalls when you turn the key into the ignition, it is likely that alternator failure has occurred. Since the alternator is responsible for charging the battery and igniting the spark plugs that fuel the engine, it is the one aspect of the engine that allows the vehicle to start. If your vehicle is stalling, this means that the alternator problem is relatively advanced and that you should have a mechanic take a look at it as soon as possible.
  • Strange Noises: Most vehicles make a variety of noises. While some are normal and harmless, there are some that signal a need for immediate attention. The usual noises included in alternator failure are a high-pitched whining or a deep growling caused by the alternator pulley being shifted out of alignment. These noises can be startling but can be fixed with a simple trip to a mechanic.
  • Electrical Failures: Both your headlights and other electrical systems can begin to malfunction if your alternator is failing. If your headlights are unusually bright or dim, this can show that your alternator is in need of replacement. This is because, without the alternator, the battery cannot supply the headlights of your vehicle with consistent voltage, resulting in unusual malfunctions. Other electrical systems such as the radio, dashboard lights, air conditioning, and power locks can begin to fail as well as the alternator goes out.

Visit the Certified Diesel Solutions “news and events” page for more information about alternator failure.

Faulty Transmission:

Another aspect of your truck’s engine that can cause a loss of power is a faulty transmission. Your diesel engine’s transmission is responsible for turning the alternator power into torque. Torque is essentially the force that creates engine power. This is essential to keep your engine running at an efficient speed. Here are some of the key signs that your transmission may be failing you:

  • Difficulty Shifting Gears: If your diesel truck’s gears are getting stuck or simply taking too long to shift, this is a clear sign that the transmission in your truck may be failing. Slow shifting gears indicate imbalanced transmission pressures. If left unresolved, the slipping of these gears can leave your vehicle entirely inoperable. Check to see if your transmission filter is dirty, as this can often be the reason why your transmission fails. If this does not solve the problem, seeing a certified diesel mechanic can be helpful.
  • Smells: As interesting as it may sound, you can sometimes smell if your transmission is out of whack! Faulty transmissions are usually accompanied by a strong burning scent, due to the fact that your transmission fluid may be breaking down. The breakdown of transmission fluid can occur due to the age of the fluid or that the fluid isn’t properly lubricating the transmission itself. If you notice this, take it to a mechanic immediately.
  • Vibrations: If you notice that your diesel truck begins to vibrate excessively when shifting gears, especially on bumpy roads, this could be a clear sign of an ailing transmission. In this case, a certified mechanic will have to recalibrate your clutch or replace it entirely.

Get Your Diesel Engine Checked Routinely by A Diesel Mechanic

Any one of these warning signs of a diesel disaster can be easily avoided by scheduling regular maintenance checkups for your diesel vehicle. There are few things worse than being slammed with deliveries as one of your trucks malfunctions, possibly leaving your driver stranded on the side of the road. Luckily, the team of professional mechanics at Certified Diesel Solutions is here to help you avoid any and all roadside inconveniences.

Since 2009, Certified Diesel Solutions has been offering top-of-the-line service to the tractor-trailer owners and fleet managers of the Knoxville area. We stand ready to fix any diesel-related concerns you may have by working with the latest and greatest in repair tools and diagnostics equipment. We understand that time and money are of the essence when working in the rigging industry, so we also provide preventative maintenance checks to ensure that your rigs stay on the road. Personal relationships and trust are the names of our game, and we pride ourselves in the connections that we’ve been able to form from consistently providing reliable service. So, if you ever find yourself in what feels like the middle of a diesel disaster, or simply require a routine maintenance company, visit our website or call us at 865-964-6598.