DRILLMASTER – Maintaining Emissions Compliant Engines — Part 2
February 10, 2011The October 2008 issue of Trenchless Technology included an article discussing the role fluids play in the proper operation and maintenance of newer emissions compliant engines. As stated then, proper care of these engines still starts with the simple things such as fluids. This article covers how the use of those fluids may have changed since 2008.
Fuel: Diesel fuel remains the fluid most likely taken for granted. Poor quality fuel causes issues ranging from reduced power and filter plugging to injector and piston failure. Users should always follow the fuel recommendations in their operator’s manual, which will usually include a reference to ASTM D975 specifications. Fuel purchased from reputable sources should easily meet these specifications. The risk of contamination in such fuel is also reduced. Finally, users should take care to avoid introducing contaminants during storage and handling plus use their fuel in a timely manner.
Fuel sulfur content: Sulfur content continues as an important characteristic of diesel fuel. Since mid-2010, diesel fuel refined for off-road use meets the same sulfur specifications as on-road fuel, 15 parts per million or less. This fuel is called ultra low sulfur diesel, or ULSD. Two emissions reduction technologies, diesel particulate filters (DPFs) and cooled exhaust gas recirculation (EGR), are sensitive to fuel sulfur content.
Most, if not all, on-road trucks built since 2007 have both technologies. Off-road, some engines began using EGR in 2006 and many larger (above 174 hp) engines will employ both EGR and DPFs starting in 2011. Using higher sulfur fuels, such as those intended for marine or locomotive use, may cause DPF or EGR system failure and result in expensive repairs.
Diesel exhaust fluid: The term diesel exhaust fluid, or DEF, refers to a particular solution of water and urea. An emissions technology called selective catalytic reduction (abbreviated SCR) consumes DEF as it reduces certain exhaust pollutants. Many 2010 and later on-road trucks, as well as some 2011 off-road engines use this technology. While new to the United States and Canada, Europeans have successfully used DEF for several years calling it by a trade name, AdBlue. Users must refill with DEF on a regular basis but, depending on tank size, not as frequently as fuel. Fluid consumption is expected to be 2 to 5 percent of diesel fuel. With high water content, DEF freezes around 15 F (-9 C). Properly constructed tanks are rugged enough to handle frozen fluid and include heaters to insure complete system function shortly after start up.
During off-season storage of SCR equipped trucks or equipment, DEF may evaporate and leave troublesome residues in tanks. To avoid this issue, users may consider draining their DEF tanks before placing such products in long term storage. Lastly, since urea is corrosive, users should take care when filling their tanks and wipe up any spills. As always, truck and equipment owners and users should read and follow the instructions in their operator’s manual.
Lube oil: The American Petroleum Institute’s (API) highest service category for diesel engine lube oil remains CJ-4. API introduced CJ-4 in 2006 to meet the needs of emissions compliant engines using DPFs and ULSD. At that time, off-road fuel sulfur limits were greater than ULSD and some off-road engine manufacturers recommended shorter oil drain intervals if using CJ-4 with those fuels. With last year’s change mandating ULSD for off-road use, users of those engines can now service their lube oil at the normal interval when using CJ-4. Users should always follow the lube oil recommendations in their owner’s manual.
Conclusion: The service requirements for diesel engines meeting the latest emissions regulations are very similar to those for their predecessors. Diesel exhaust fluid adds a maintenance and consumable item for some engines. But, by simply following their truck, equipment or engine manufacturers’ operation and service recommendations, owners and operators can be confident their engines will give them many hours of reliable service.
David Campbell is design team manager with engines and emissions compliance at The Charles Machine Works Inc. All Drillmaster Reports are reviewed by the Drillmaster Advisory Board: Frank Canon, Baroid Industrial Drilling Products; Richard Levings, The Charles Machine Works Inc.; Ron Lowe, Myers-Aplex, a Pentair Pump Co.; Tod Michael, Vermeer Corp. and Trevor Young, Tulsa Rig Iron.