EGR Diesels: Critical Care Counts
This is not a good time to take chances with your lube program.
Doug Condra
President/Publisher
Those new exhaust gas recirculation engines, foisted upon the industry last fall by an Environmental Protection Agency eager to punish U.S. diesel builders, are receiving mixed reviews from the field.
Concerns that EGR engines would suffer a variety of ills because of higher heat and other factors have, in fact, materialized for some fleets. For others it's so far, so good.
For the latter that's a good thing, but it could change for them, too. There are relatively few of the new diesels in fleet use, and they haven't been in operation very long.
The bigger question is, how will they hold up over three years, four years, five years? Nobody can say. What is for sure is that how they are maintained can make them or—literally—break them.
According to the experts, an EGR engine's life-span will largely revolve around lubrication. Not much new about that, but these engines are apt to be a lot more sensitive to when oil and filters are changed, and the type of oil used. The new CI-4 oils, with better performance at high temperatures and potential for longer drain intervals, are a must (see The New Oils, page 90).
Some EGR engine sumps are bigger, requiring as much as 25% more oil. Recirculating exhaust gases, as required by the EPA regulation, means it generates a lot more combustion soot in the crankcase oil than a non-EGR powerplant. All that, despite a larger, more efficient filtering system.
Soot-laden oil can quickly wear down engine components. Plugged filters and oxidation that changes the viscosity of the oil will accelerate soot formation. That combination could make all those early fears for EGR engines become a nightmarish reality.
One established maintenance practice is to lengthen or shorten oil change intervals based on field oil analysis. An engine that cruises a lot, for example, isn't likely to need its oil changed as frequently as one in severe, dirty service.
That practice is being discouraged in EGR engines, at least for starters. It appears that the best way to begin an oil change program is to strictly follow the engine manufacturer's recommendations until you get to know how the EGR engines are going to behave for you.
You can do that by using electronic engine analysis to collect the important performance data. Then you can determine whether it's wise to extend the oil and filter change interval.
In the meantime, if you're running EGR engines, it's probably not a good idea for your maintenance department to boldly go where manufacturers say you shouldn't.
