Heavy-Duty Diesel Engine Maintenance

This page last reviewed September 9, 2013

Maintenance For a Diesel Engine With a DPF

Owners and operators of diesel vehicles and equipment must follow good engine maintenance practices, in particular with engines that are equipped with DPF.  Installation of a DPF to control emissions does not in any way mean engine maintenance can be reduced or neglected.  Rather, proper engine maintenance is a key part of staying in compliance with the ARB's in-use diesel fleet regulations and is critical to ensuring that a vehicle equipped with a DPF continues to operate without problems. Improper care of your engine and retrofit device can lead to:
    -  Expensive repairs and replacement parts
    -  Voided warranty
    -  Engine malfunction or breakdown
    -  Non-compliance with air pollution laws

Protect your investment by understanding the needs of your new system.

What could happen if the engine is in poor condition?
The DPF captures soot from the engine and can mask engine problems that were formerly detectable by observing exhaust smoke characteristics.  This is why keeping the engine in a proper state of maintenance is critical.  A poorly-maintained engine produces more soot, leading to plugging or more frequent cleanings which can prevent the DPF from performing at its verified level.  Also, it can cause damage to the retrofit and the engine if ignored.  Reducing soot from your engine reduces filter plugging and cleaning. 

What are some methods of maintenance I can use?
Proper engine maintenance is necessary for compliance with ARB regulations.  Some methods of maintenance include:

Fuel injectors: Repair and replace at intervals required by the engine manufacturer’s maintenance schedule. Worn fuel injectors can lead to excessive fueling and more soot generation and accumulation in the filter.  Fix worn hydraulic injectors to stop lube oil leaks into the fuel.

Air filters: Replace at intervals required by the engine manufacturer.  Dirty air filters reduce air flow to the engine leading to more soot generation.

Turbo chargers: Check turbo charger for proper operation and excessive wear.  Turbo chargers that do not produce sufficient air or have leaking seals lead to more soot or the presence of lube oil in the exhaust.

Fuel filter: Replace at prescribed intervals.  Look for the presence of lube oil in the fuel filter during regularly scheduled maintenance.  A blackening of the filter may indicate that oil from the crank case is mixing with the fuel due to a leaky injector or worn seals.

Fuel: Periodically inspect fuel in the on-board fuel tank for signs of lube oil contamination (black in color). Inspection should be done prior to refueling.  A blackening of the fuel may indicate mixing of crank case oil with the fuel.

Coolant: Monitor your coolant consumption by keeping a log of the coolant added to the engine.  Coolant leakage can poison the DPF catalyst leading to filter plugging.

Lube oil: Change the lube oil at mileage intervals indicated by the engine manufacturer and its track usage. Some of the components in lube oil can collect in the DPF leading to filter plugging. Therefore, it is important to ensure that the engine is not consuming lube oil at a rate higher than recommended by the engine manufacturer.  If the lube oil consumption exceeds specifications, the engine must be repaired.  Increased lube oil consumption also leads to increased ash load, resulting in more frequent cleanings.  The ash is not destroyed by regeneration process that breaks down the soot.  The result is an increase in retrofit device cleaning frequency which is costly and involves downtime.  Low ash (CJ-4) lube oil is recommended by many manufacturers to reduce additional ash build up.

· Track lube oil usage by keeping a log of how much oil is added to the engine between oil changes.  

· Never put clean or used lube oil, additives, or alternative diesel fuels that are not authorized by the retrofit device manufacturer in the fuel tank.

· Use low ash lube oil (CJ-4).

 Additional Information on Retrofit Device Maintenance