Three Common Problems With Diesel Engines

If you run a commercial fleet, then odds are good that some or even all of your vehicles use diesel engines. The high peak torque at low engine speed makes diesels well suited to heavy-duty usage when getting a load moving is more important than peak power. The fuel efficiency offered by diesel engines is a great reason for their popularity in commercial fleets as well.

This doesn't mean that diesels are without their fair share of problems, however, and any fleet where vehicles are kept for the long-term is likely to require repairs sooner or later. Here are just three problems that are common on diesel vehicles.

Fuel Injector Failures

The fuel injection systems on diesel engines tend to be even more vulnerable to contamination issues then those found on traditional gasoline engines. While bad fuel injectors will eventually stop your vehicles dead in their tracks, the initial symptoms may not be obvious. Initial symptoms may include difficulty starting the engines or reduced fuel economy. As the problem gets worse, the actual performance of the vehicle will degrade and eventually serious symptoms such as misfires or hesitation will be plainly obvious.

Fuel Delivery Issues

While fuel injectors may be a common problem on many diesel engines, issues can pop up elsewhere in the fuel delivery system. This can include an old or clogged fuel filter or a failing fuel pump. These items are responsible for actually delivering the fuel to the injectors, so a failure in either case is likely to have similar symptoms. A fuel pump that fails entirely will eventually stop your vehicle from starting at all. As with fuel injector problems, these issues are often caused by contamination within the fuel supply or fuel tank. If you suspect that any of your vehicles have been using contaminated diesel, it may be a good idea to run some diesel fuel injector cleaner through the system and then immediately replace the fuel filter.

Dirty, Smoke Exhaust

Modern diesel engines run clean and the days of black smoke–belching monsters are long past. If your diesel vehicle's exhaust is leaving a trail of smoke behind it, then something has gone wrong. Black smoke on a diesel engine usually indicates that some amount of fuel is entering the combustion chamber without burning. Unlike regular gasoline engines, diesel engines take in as much air as possible with each stroke and only the fuel is controlled by the throttle position. When your exhaust emits black smoke, it means that more fuel is entering the combustion chamber than can be burned efficiently.

There are a number of possible causes for this, including leaky injectors. A restriction in the air intake system can be a possible cause as well, since the reduced amount of air that is entering the combustion chamber will in turn reduce the amount of fuel that can be burned successfully.  

Contact a company that offers diesel repair services to learn more.