Diesel Particulate Filter

The Diesel Engine

In 1897, Rudolf Diesel developed a high-compression engine that went on to carry his name.

Diesel Engines function by compressing air into the engine’s cylinder.  Such intensifies the air’s temperature to such a high degree, it ignites the diesel fuel in the combustion chamber.  Diesel engines operate differently than other engines, which are spark ignited and use spark plugs and run on gasoline.

Diesel engines are very reliable, last longer than gas engines, and are more cost effective to run.  Mostly large, 18-wheeled trucks, which transport goods and products, use Diesel Engines.  Other vehicles and machinery that use Diesel Engines include:

  • Construction Equipment and Vehicles
  • Cargo and Cruise Ships
  • Trains and Locomotives
  • Buses
  • Generators

Diesel engines, however, release chemicals and compounds (i.e. pollutants) into the air. In 2007, pursuant to Environmental Protection Agency Regulations, diesel engine manufacturers began adding Diesel Particulate Filters (DPF) to exhaust systems.   DPFs decrease nitrogen oxides and eradicate the distinctive diesel odor.  In 2010, manufacturers added urea, which further advanced combustion proficiency.

Diesel Particulate Filter

How the Diesel Particulate Filter Works

As the truck engine runs, the engine injects fuel into the exhaust stream. The filter seizes dust, soot, and diesel particles and keeps them from being released from the exhaust pipe.

What Can Go Wrong

When fuel goes through certain chemical processes, the reactions produces heat and converts soot into ash, which can pile up, affecting the filters.  Failures of valves, fuel injectors, coolers, and/or the turbocharger can also clog the filter with coolant, raw diesel, and oil.  When contaminates reach a particular level, the filters can clog. If that happens, exhaust flow becomes obstructed and interferes with proper engine function.

DPF Regeneration

When Diesel Particulate Filters are clogged, the engine needs to be regenerated or cleaned.  This is done two ways:  automatically or manually.

  • Automatic Regeneration: there are two kinds:
  • Passive Regeneration: when a mostly constantly working wheel loader reduces the amount of particulate matter before it builds up.
  • Active Regeneration: when the system’s computer recognizes the problem and begins a course of action that injects diesel fuel into the engine’s cylinders. The heat eventually reduces the particulate in the DPF to ash.
  • Manual Regeneration: a light will come on the truck’s dashboard, notifying the driver that they need to initiate manual regeneration.  In order to avoid costly damage and prevent any further problems, it is imperative that the driver immediately begins the regeneration process.  They have no choice, really, for if the driver takes no action and keeps on driving, an alarm will sound and, ultimately, the engine will go into “limp-home mode,” wherein the power and RPMs are so reduced, the operation is impossible.

The Manual Regeneration Process takes around forty-five minutes to an hour. Trucks have a button that the drivers need to activate in order to begin the process.  The driver must first, however:

  • Drive and park in a well-ventilated area. Outside is the best place.  But, not on grass or any other place that could catch fire as the filter gets hot.
  • Place the truck in neutral
  • Activate the hand brake
  • Press and hold the DPF button for a few seconds
  • Leave all pedals alone

Downsides to DPFs

Of course, a Diesel Particulate Filter protects our health, the animals, and the environment.  And, that’s great.  The downsides include the potential damages to an engine should they not be maintained.  Plus, they cost about $5,000.  A reconditioned Diesel Particulate Filter works just as good, however, cost half that amount and is a great alternative. For more information please do not hesitate to contact us.