Diesel engines are standard in many workhorse vehicles, including both heavy-duty and light-duty trucks. You can find these engines doing the hard work due to their power and reliability. This latter advantage also means that many businesses still operate fleets of fairly old diesel vehicles, many of which have spent years or even decades on the road.
Keeping old vehicles in service makes plenty of sense from a business perspective, but it also requires your operators and maintenance teams to remain vigilant. While you should never ignore a problem on any fleet vehicle, these three repairs are especially critical on older diesel engines with many miles and years under their belts.
1. Overheating Problems
A faulty cooling system can bring down any internal combustion engine. If your diesel runs too hot, the lubricating properties of your oil will begin to fail, friction will increase, and internal parts may even warp. Typical causes of overheating on diesel engines are the same as for any motor: cooling leaks, faulty water pumps, bad thermostats, and so on.
However, clogged fuel injectors are one overheating problem that's unique to diesel engines. Unlike a gas engine, a diesel engine controls the amount of fuel that enters the combustion chambers to alter its torque. Any issue with fuel delivery can impact the combustion cycle, potentially causing your engine to overheat even with an otherwise functional cooling system.
2. Lack of Lubrication
No engine can survive for long without lubrication, but an older diesel may be especially vulnerable to minor fluctuations in oil level. As engines age, the internal parts tend to wear down, making them more susceptible to issues resulting from poor lubrication. These problems can also occur due to infrequent or poor oil change habits.
If you're maintaining a fleet of older diesel vehicles, never ignore signs of oil loss. Any leak can progress rapidly, potentially going from relatively slow and minor to catastrophic. Repairing leaking hoses, gaskets, and other sources of oil loss can be one of the best ways to ensure your fleet vehicles last for as long as possible.
3. Water Separator/Fuel Filter Issues
Unlike gasoline, diesel tends to pick up a lot of moisture. Even if you don't leave your vehicles to sit for long, water may be present in the fuel. As a result, diesel engines typically include a water separator near the fuel filter to collect water and allow it to drain. These items require periodic maintenance, and too much water in the fuel can cause damage to your engine.
With older vehicles, it's critical to check the fuel filter housing and water separator occasionally. The housing requires replacement if there's any sign of corrosion, and it's usually a good idea to check for damage elsewhere in the fuel system. Water can quickly kill any diesel engine, so these repairs are essential to keeping an older fleet of diesel vehicles on the road.
Contact a local auto shop to ask about diesel truck repair services.