Best Practices

Tier IV Engine Maintenance Tips

Tier IV engines were developed to reduce the amount of particulates and nitrogen oxides entering our air from construction equipment and other machines. They were developed so that engines would meet the emissions in the more stringent EPA standards, while providing better fuel efficiency and performance than their predecessors.

Types of Tier IV engines

There are two primary types of systems that allow engines to be Tier IV compliant, Cooled Exhaust Gas Recirculation (CEGR) and Selective Catalytic Reduction (SCR).

CEGR – this system uses an exhaust gas recirculation cooler (EGR) to lower the combustion temperature by mixing fresh air with exhaust gas. Particulates are then trapped by a diesel particulate filter (DPF) to prevent them from entering the air. The remaining emissions are N2 and CO2, both harmless gases.

SCR – Selective Catalytic Reduction injects a liquid reductant agent known as diesel exhaust fluid (DEF) through a special catalyst into the exhaust stream of the engine. This process starts a chemical reaction that converts nitrogen oxide into nitrogen and water, both harmless gases.

Choose low sulfur diesel fuel

Both the EPA and the Tier IV engines themselves require ultra low sulfur diesel (ULSD), which contains only 15 parts per million of sulfur. Using non-ULSD fuel may cause serious damage to your fuel system, DPF system, or exhaust after treatment system, as well as lead to possible fines or penalties from the EPA. Ultra low sulfur diesel is available at fueling stations across the country.

Use the right oil for Tier IV engines

The transition to Tier IV engines has changed the type of engine oil your new machines should use. It is now recommended to use CJ4 oils, as they are designed specifically to work with aftertreatment systems while maintaining expected performance and service intervals.

Using older or incorrect oil may cause costly damage to your equipment's emissions components. To avoid accidentally using older types of oil with new machines, we recommend switching all your equipment, Tier IV and otherwise, to CJ4 oils. They won't hurt the older machines and having only one type of oil will prevent confusion.

Be sure to check your owner's manual to see if your engine has a crankcase ventilation filter. If it fails, over time, the engine will experience excessive wear and be prone to oil leaks from the pressure build up. Due to the high pressures in the crankcase, oil mist, particulate matter and water escaping past the piston rings and piston ring gaps can travel throughout the engine, causing many different problems.

DPF maintenance tips

Most diesel particulate filters are designed to last for a minimum of 3,000 to 3,500 hours. The DPF is cleaned using a regeneration process that occurs while the filter is on the machine. When it comes time to change out the filter, the majority of machines have it positioned for easy access to facilitate service. Check your owner's manual to find its exact location on your specific piece of equipment.

DEF maintenance tips

Refilling the diesel exhaust fluid tank should be incorporated into a regular maintenance or refueling routine. Machines that use DEF will have a DEF gauge and a warning signal when the fluid level is low, similar to a fuel gauge. Always be proactive about checking diesel exhaust fluid levels and change the supply module filter at the interval required by the manufacturer.

Questions about Tier IV engine technology or maintenance? Contact Kelbe today.