Truck Topics

2007 Truck Emissions Maintenance

At this point in the development of engines compliant with 2007 emissions requirements, manufacturers have generally been forthcoming about them. While many are expressing concerns about cost and performance, the subject of overall maintenance seems to raise fewer eyebrows than longevity issues, the price and availability of ultra low sulfur diesel and new oil, and care of the newly added after treatment device, the diesel particulate filter, to name a few concerns. To be sure, emissions standards have upped the ante. In ’04, NOx limits were lowered from 4.0 to 2.0 g/bhp-hr. In ‘’07 NOx threshold will be a measly .20 g/bhp-hr.

But while engine manufacturers have tweaked their existing EGR systems and added after treatment, the diesel tech’s job has not gotten appreciably more difficult nor time consuming, except as regards the diesel particulate filter, which  will require a little under two hours to remove from the truck, clean and put back on. A mask and rubber gloves is needed for this job and the filtered ash disposed of. There are no environmental regulations yet about disposal. Bill Linder, industry manager for agriculture and construction at SPX Service Solutions, says the detritus from the cleaning process amounts to “kitty litter with a little zinc,” and believes most shops will dispose of it in a landfill with the exception of those facilities in California.

IN THE CAN

The unit is held in place by v-clamps and is easily removed, although its weight, about a hundred pounds, will require some muscle. Operators should be aware of clamps and check them periodically since the entire after treatment unit’s weight, about 180 pounds, creates significant drag on fixtures. Volvo offers two placements for its “can”, one frame mounted unit behind the fuel tank on the passenger side, the other mounted behind the cab. The frame mounted unit is best removed with the help of a transmission jack. The back of cab unit is removed with a rolling unit that clamps to the can.  Maintenance costs for both types will be around $150. Volvo’s new D11, D13, and D16 engines use cooled EGR with the added catalyst and diesel particulate filter, making its ’07 effort much like other engine manufacturers. Volvo’s new engines will have longer oil drain intervals.

It should be noted that after treatment devices can cause exhaust temperatures to rise, creating a possible hazard when the unit must be handled. Manufacturers have said they will provide methods to lock out this active regeneration when it poses a danger. At Volvo, for example, the driver can postpone the active regeneration process if it will occur at a time during operations that is not desirable. Familiarity with this possibility and the lock out procedure is advisable. Besides t when service is being done, some drivers may decide to postpone this event until after climbing Fancy Gap or Donner’s.

In consideration of these factors, some will opt to use swing units rather than incur time losses, particularly if the DPF is being cleaned outside a typical preventive maintenance event. An outsource may do the whole job or simply pick up the filter and return it after it has been cleaned. Steve Ashburn, a 2007 product support consultant for Cat, says Cat’s DPF can be serviced without removing it from the truck, which will save some time and aggravation but means a swing unit is a necessity if time is to be saved.

COSTS, INTERVALS, OIL AND FUEL

Some costs, like new oil and DPF cleaning are, at least in some cases, negated by the need for reduced oil capacity. This is the case with Mack’s new MP7 and MP 8 engines, and Mercedes MB diesels marketed by Detroit. A decision to use third party DPF cleaners rather than purchase the DPF cleaning unit at a cost of $6000 to $8000, can save smaller fleets money in the long run. Eventually, however, the cost of outsourcing will pass the cost of the machine. Chuck Blake, technical sales support specialist at Detroit Diesel, foresees a yearly up tick in greenbacks somewhere in the range of $350 to $400 in total maintenance expense if cleaning of the DPF is necessitated by mileage accumulated. Blake notes a DPF integrated properly into the system may mean a cleaning may not be necessary for two to three years, depending upon mileage.

Blake also thinks, ”the basic no brainer oil change remains at the 15,000 mile interval,” adding that no oil analysis is necessary at this level of service if CJ-4 oil and ultra low sulfur fuel is used consistently. “Mixing use of pre-’07 and ’07 oil and fuel will make oil analysis more necessary.” Blake added. For example, engines that continue to use CI-4 or other pre-’07 formulations will carry more ash, making analysis at extended intervals a more necessary precaution. Given availability of ultra low sulfur diesel, another EPA mandate, and new CI-4 oils, operators who use both rather than a mix of old and new, will be ahead of the game. Use of today’s diesel in engines with catalyzed DPFs will cause the catalyst to be contaminated and it will have to be replaced after having died slowly. This is an unwarrantable event and the cost will be borne by the truck owner. ULSD is supposed to be available nationwide by October 15, 2006. 

As shown above, the ’07 solution includes the addition of after treatment in engines where there was none and the addition of a diesel particulate filter in those already sporting an oxidation catalyst. Blake notes that oxidation catalysts burn soot but do not burn ash. Unburned soot from the oxidation catalyst, and ash, which does not burn, are collected by DPFs. This makes it necessary for those using pre’07 oils to clean DPFs more frequently. Typical intervals for fully up to snuff operation should be between 150,000 and 400,000 miles, according to Blake.

After treatment devices have occasioned a great deal of worry among fleet maintenance executives while engine manufacturers continue to pooh pooh the notion they are a big deal. Most engine guys concur with Blake about the 150,000 mile cleaning interval. The EPA requires filters to run at least 100,000 miles before they need cleaning. Dave McKenna, Mack’s power train products manager, adds that a 400,000 mile trade cycle will require only one more DPF cleaning after the 150,000 mile interval.

In light of issues surrounding DPF maintenance, some experts believe a cottage industry may develop. McKenna thinks entrepreneurs interested in outfitting a pickup with the $6,000 to $8,000 cleaner could provide service to fleets. The supposition is these entrepreneurs would troll the fleet waters for likely fish, offering a service fleets have opted to outsource. One can envision vast administrative snafus in the scheduling of such service, particularly among larger fleets, causing some to go for broke and buy their own equipment. The real problem might be coordinating regular preventive maintenance schedules with DPF maintenance given the questions still afloat as to how to administer this new maintenance requirement. 

However, Tom Newby, director of field maintenance at Old Dominion Freight Lines, says he currently does oil changes every 90 days to meet California standards. He says Old Dominion will try to align DPF service with preventive maintenance but sees no difficulty since “manufacturers will try to get 300,000 miles between DPF services, so coordinating preventive maintenance and DPF service shouldn’t be a problem.” Newby will begin testing Cat C-13 engines in April on his current PM schedule. He does not foresee any real problems maintaining the ’07 engines.

WISDOM FROM THE ENGINE GUYS

Cummins literature indicates only that their Cummins particulate filter maintenance will have to be performed by a Cummins approved cleaning method. “Cummins will allow filters to be exchanged between vehicles or the customer may choose to use a recon exchange,” according to Cummins. Standard oil change intervals are unchanged and all fuel, coolant, and lube filters will be the same.

The only added requirement for maintenance will be a Fleetguard coalescing filter fitted to the crankcase ventilation system.  This filter will have to be replaced every third or fourth oil change. Cummins says it is “working to ensure that the ash cleaning interval for the diesel particulate filter occurs during an engine or vehicle maintenance interval.” In essence this means that factors including duty cycle, oil consumption and oil type are being considered in the particulate filter maintenance interval algorithm. Cummins remains committed to its standard heavy duty engine technology, EVRT, and the G-2 fuel injection system as well as cooled EGR.

Ashburn says Cat’s basic service intervals, typically 30,000 miles for the C13 and C15 remain unchanged. Cat has extended its ACERT technology with clean gas induction, a process that takes cleaned air out of the DPF, returning it to the engine through a 2.5 inch pipe. Cat does not see any added maintenance issues connected to this system except that engines rated above 500 will have two DPFs rather than one. The closed crankcase ventilation system required by new emissions standards and fitted to all engines has a pop off filter that is replaceable every 100,000 miles. Some manufacturers are using washable filters in the crankcase ventilation system rather than a replaceable device.

Over at Mack, McKenna says oil change intervals will be stretched from the current 25,000 miles for heavy duty on highway applications to somewhere between 30,000 and 45,000 miles depending upon duty cycle. “The 45,000 mile interval is a strictly on highway number for trucks averaging over 6.2 miles per gallon running more than 100,000 miles per year,” McKenna says. Trucks averaging below 6 mpg and running less than 100,000 miles a year in extreme service like peddle runs will need to adhere to the 30,000 mile limit.

There is a reduced need for one maintenance procedure in particular in Mack’s new “clean sheet” engines, the MP7 and MP8, according to McKenna. “ There will be two thirds less need for valve settings over the life of these vehicles,” he says. “This is true because the engines are now single overhead cam as opposed to overhead valve engines.”

Mack is one engine manufacturer that does not support washing the DPF. Indeed, some DPFs, like Mack’s, cannot be washed. Blake notes that washing extends the time interval necessary between cleanings and is thus more effective than the typical vacuum method, “and will probably be more expensive.” Mack’s solution to crankcase breather filtration is a small centrifugal filter that returns vapor as condensate to the sump, and is not atypical among its ’07 brethren. McKenna says it takes five minutes to clean and need only be done every third oil change.

CLEANING THE CAN

SPX Service Solutions makes the air cleaning solutions for DPF cleaning. This technology was developed in conjunction with Cat, which holds a number of patents on various components. SPX developed the cleaning process and appears to be the first and most prominent manufacturer for this device. Bill Linder says four engine manufacturers have bought the machine for testing already. And while OE’s will determine which product to use, SPX is poised for robust sales. SPX also designed and builds a DPF handler of the sort used by Volvo to remove its back of cab mounted canister.

The cleaner is a mobile unit designed to make the work as quick and simple as possible. “We used the idea that the job should be as much like an oil change as possible,” says Linder. While the machine itself can be used for any filter, there are adapters specific to each style of after treatment canister. Linder notes SPX hopes the next generation of technology will permit more canister types to remain on the truck while being serviced.

A filter’s cleanliness is measured by the amount of pressure drop found when the unit is tested by the technician. Linder notes that SPX’s machine has shown cleaning allows pressure to remain at about 95 per cent compared to a new filter. Probably the most difficult part of the tech’s job is insuring the proper fit of the adapter.  Proper fit insures the air that does the cleaning is pulsing properly. Air is pulsed rather than streamed because pulsing more efficiently breaks down the coagulated fingers of ash that form as ash collects.

Proper cleaning also requires the DPF to be checked through a built-in program on the machine’s monitor, then cleaned. Some engine manufacturers are suggesting the DPF be baked before being cleaned. This will turn any soot to ash and insure that proper purging of the DPF results.