Will '07 Engines Cause More Headaches for Your Techs?

Service technicians who work on your medium- and heavy-duty vehicles will need some additional training as you add '07 trucks to your fleet. "Training will be key to getting a 2007 truck back on the road," says Steve Ashburn, 2007 service readiness manager, Caterpillar.

In the case of Caterpillar engines, there are new systems that need to be learned. "They will need to know and understand the three new systems that Caterpillar has added to meet the 2007 emissions: Clean Gas Inductions (CGI), Caterpillar Regenerations System (CRS) and the diesel particulate filter (DPF)," says Ashburn. "We are providing various training opportunities for technicians to learn about these new systems, including video (Tech Tips), WebEx (on-demand training via the web) and hands-on, both in Peoria and in the field during the first quarter 2007."

Mack recently unveiled its MP family of engines, which will serve as its platform to meet emissions regulations into the future. "Service technicians are already familiar with two of the key technologies featured in these engines: exhaust gas recirculation (EGR) — a version of which is used in our '04-certified ASET engines — and the V-MAC IV electronics system," says David McKenna, Mack powertrain products marketing manager. "The only additional technology for 2007 is a DPF."

Similarly, Cummins will be adding a DPF with its existing engine line. "Cummins 2007 engines will meet the stringent U.S. EPA 2007 standards for on-highway trucks by integrating the Cummins Particulate Filter with its current cooled EGR engine technology," says Cyndi Nigh, Cummins. "Using a stable engine architecture assures customers that the Cummins engine they purchase in 2007 will basically be the same engine they are operating today — and gives them confidence in the performance, reliability and durability of their 2007 Cummins engine."

Larry Dutko, general manager of the EPA '07 project, Freightliner, says the DPF and the engine really work together as a system. "The engine plays a big part in how the filter works. In fact, the filter is now almost part of the engine because the two have to work together. It is more engine-related than the particulate filter, which surprises a lot of people because there is a big awareness of the particulate filter," he notes. "So on the engine side, Detroit Diesel technicians are going through all of the schooling they need right now and introduction to the engine changes."

After-treatment fears unfounded

Early rumors of maintenance-intensive particulate filters — which replace the muffler — have proven unfounded. These particulate filters actually promise long service intervals and rather short downtime for cleaning.

"We are predicting a minimum of 150,000 miles or 4,500 engine hours for the first ash cleaning," says McKenna. "The interval should be greater for the second cleaning."

These devices will require very little attention from the operator or the technician. "The DPF is a self-managing device that collects or traps soot particles and has the ability to passively using existing hot exhaust gas during normal duty cycles, and to actively regenerate (self clean) upon ECU demand," says McKenna. "The only manual intervention will be to clean out the collected residual ash."

It is impossible to predict exactly when the DPF will need to be cleaned. "Cleaning intervals will depend on a number of factors, including duty cycle, oil consumption and type of oil used. The exact interval will vary by application," Nigh explains. "We expect the interval for a typical vocational application to be approximately 200,000 miles or 6,500 hours."

"This is not going to be a high-maintenance item at all," says Dutko. "The particulate filter has no moving parts. That's what is nice about it. It sits there. You add heat to it. It oxidizes the soot and it collects the ash."

Cleaning the DPF will require a specialized tool. "They are mostly air pulsing machines," says Dutko. The DPF is removed and placed in the air pulsing tool for approximately 15 minutes. The air pulses then loosen the ash so it can be removed. This takes roughly 30 minutes. So the whole process can be done during a normal PM.

"The design target for cleaning is 30 minutes or less, not including removal and installation time from the vehicle," says Nigh. "Cummins will allow filters to be exchanged between vehicles, or customers may choose to use a recon exchange. The particulate filter is the only component of the Cummins Particulate Filter system that will require service."

The cost of DPF cleaning tools, coupled with the infrequent demand for cleaning, means most customers will not be able to justify the purchase of these tools. "They are all in about that same $10,000 to $12,000 range," says Dutko. This will leave the cleaning to the dealer network.

Mack has also addressed this issue by offering a DPF exchange program. "We anticipate initially the core exchange program through Re-Mack will be the common path until economies of scale dictate local cleaning and repair," says McKenna.

Handling of the ash after it is removed from the DPF depends on your location. "Every repair shop will have to consult its local ordinances to determine if the ash is considered hazardous material and how it should be handled," says Ashburn. "There are no federal guidelines. Some states do have guidelines."

Crankcase ventilation changes

"Crankcase gases will be included in emission measurements for the first time in 2007 engines," says Nigh. This has led to crankcase ventilation systems that prevent oil residue associated with engine blowby gas from escaping.

There are a couple of different approaches being used: closed crankcase ventilation and high-efficiency ventilation systems with coalescing filters. "Caterpillar will be using open crankcase ventilation on our heavy-duty C15 and C13 engines, and closed crankcase ventilation on our medium-range C9 and C7 engines," says Ashburn.

The engines with open crankcase ventilation will be fitted with filters. "The filter on the C15 and C13 will need to be replaced every third oil change (90,000 miles)," says Ashburn.

"The coalescing filter system, made by Cummins Filtration, will offer the additional benefit of eliminating oil drips," adds Nigh. "A simple, low-cost filter replacement is required every fourth or fifth oil drain."

Access to the engine has not been hampered by the new ventilation plumbing. "The piping required for these systems has not made access to other components any more difficult," says Ashburn.

And these systems keep the oil where it is needed. "The oil separator is taking the oil out of the combustion stream and running it back to the oil pan," says Dutko.

In some cases, this has positive benefits. For instance, the '04 Detroit Diesel Series 60 had a normal oil consumption rate of a quart every 3,000 miles. "Now it is a quart every 10,000 miles," says Dutko. "You use much less oil in the '07 engines." And the closed-crankcase system is maintenance free.

Mack's crankcase ventilation system incorporates a coalescing filter. "The coalescing filter is a maintenance-free device," says McKenna.

Oil and fuel usage restricted

"Another major issue will be use of the correct fuel and oil," says Ashburn. "Fifteen parts per million ultra-low-sulfur diesel fuel is required (by most manufacturers) along with CJ-4 oil. (See article on page 48.) The primary reason is because of the low ash formulation of the oil. It is the ash from the oil that fills the diesel particulate filter."

In a few cases, CI-4 oil may be acceptable. "With Cummins 2007 engines, customers will be able to use either CJ-4 or the current CI-4 oil," says Nigh. "The performance and durability of Cummins 2007 engines is assured with both oils." But use of CJ-4 oils assures that customers will see no change in maintenance.

The higher ash of the CI-4 oils could lead to the DPF plugging more rapidly. "The new oil (CJ-4) has 1% ash, or less," says Dutko. "Current oils that are used today are about 1.3% ash. So there is 30% more ash in today's oils. If you don't use the low-ash oil, the service interval for your filter will increase by about 30%."

Mack requires CJ-4 oil that also meets its internal specification, Mack EO-O. This is a very low ash lube oil. "The previous oil formulas (CI-4/EO-N) had a high ash content to counter the acid loads encountered with the lube oil as a byproduct of combustion," says McKenna. "This is no longer necessary. With the requirement of the new 15-ppm ULSD fuel to meet the 2007 regulations, the sulfur content has been reduced by some 97%. Therefore, the acid loads will be reduced."

Oil drain intervals are expected to remain unchanged with the CJ-4 oil when used with ULSD fuel. "At Mack, we are increasing the heavy-duty vocational lube oil drain intervals to 300 hours and up to 30,000 highway miles," says McKenna.

Not a big change

The maintenance requirements for the '07 diesel engines have been a major concern for many in the industry. Right now, it appears the concerns were unfounded. There will be some changes and technicians will need to learn the new electrical systems. However, the uptime of the trucks should remain intact.

Of course, there is a cost associated with the new hardware. "The increased cost of this new technology has already been announced by most OEMs in their EPA07 engine escalators," says Dutko. "But serviceability and maintenance issues should hopefully be a non-event for most of our customers."

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