Aftermarket

Stay Ahead of Trouble on EGR Engines

There are few prescribed maintenance procedures for exhaust gas recirculation systems, but a watchful eye can prevent a small problem from getting worse.

February 2014, TruckingInfo.com - Feature

by Jim Park, Equipment Editor - Also by this author

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While most of the early problems have been engineered out of the exhaust gas recirculation systems on today’s clean diesel engines, corroded coolers, stuck valves and other problems still plague owners of older equipment.

EGR valves live in a very hostile environment.
EGR valves live in a very hostile environment.

Unfortunately, there’s not much you can do in terms of scheduled preventive maintenance to keep those systems working. Keeping a close eye out for telltale signs of impending failure, however, can help keep repair cost down by scheduling the event rather than being surprised by it.

“Vehicle performance, fuel efficiency and frequency of active regenerations are good status indicators,” says Roy Horton, Mack’s powertrain product marketing manager. “Adhering to a regular maintenance schedule and addressing issues as soon as they arise are vital for preventing damage to the vehicle.”

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With EGR coolers, for example, external leaks were not reliable indicators of an internal failure. Instead, Mark Ulrich, director of customer support for Cummins’ Engine Business Unit, suggests paying attention to top-up coolant.

“Fleets should be monitoring coolant consumption,” he says. “If they find they are adding, say, half a gallon of coolant per week, but there are no external leaks, that’s a good indication of an EGR cooler with an internal leak.”

Simple DPF maintenance goes a long way toward preventing expensive on-road service calls.
Simple DPF maintenance goes a long way toward preventing expensive on-road service calls.

Ulrich also says elevated sodium and potassium levels in the oil are indicative of coolant contamination that could be coming in through the EGR system.

According to Mike Dowling, an accredited technician trainer on Detroit’s on-highway diesel engines working with Clarke Power Services in St. Louis, the early EGR coolers were “fix as fail” items, and clues to a failure were not particularly easy to spot in advance.

“We tell our techs to watch for white residue at the outlet end of the cooler,” he says. “You wouldn’t necessarily be able to see a coolant leak, but burnt coolant leaves a white residue – the supplemental coolant additive – that’s visible. Once you have the cooler off the engine, you could physically test it and blow it out to remove the exhaust residue, but that’s after the fact.”

In shell-and-tube coolers like Cummins used, Ulrich says, one of the weak spots turned out to be the interface where the tubes are welded into the header plate.

“It was simply a fatigue cycle induced by the expansion and contraction of the components as the hot exhaust gas flowed through the cooler,” he says. “We changed how we flowed coolant through there and we also made some dimensional and material changes.”

John Moore, Volvo Trucks powertrain product manager, says failures seen in early EGR valves are behind the industry now, with changes in materials and design.

Contemporary engine designs improved on past weak points, and thereby reduced the number of failures.
Contemporary engine designs improved on past weak points, and thereby reduced the number of failures.

“Exhaust gas recirculation in diesel engines reintroduces exhaust soot that not only can corrode valves and coolers when condensation occurs, but can also make them stick open or closed due to excessive build-up of gummy deposits,” he says. “These failures are not as common today due to changes in component design, along with ultra-low sulfur diesel fuel as the only option for fueling. That greatly reduces the corrosion and deposit buildup.”

Ken Pickett, a customer support rep at Clarke Power Services’ Wentzville, Mo., facility, notes that EGR cooler failures were often precursors to an EGR valve failure.
“If you could put a lifespan on a cooler, you might be able to predict when they might fail and pull them before they do,” he says. “If you’ve had a cooler fail, chances are the valve won’t be far behind it.”

EPA-2007-emissions engines also saw some problems with the diesel particulate filters.

Navistar spokesperson Elissa Maurer told HDT that proper lubricant is vital to the longevity of these DPFs.

“On top of the regens, the DPF will probably require a physical cleaning sometime over its life, but using the right oils can prevent premature contamination,” she says. “Customers should follow recommended maintenance schedules for their vocation.”

These bits of advice and historical context do not necessarily apply to all engine brands, of course. They are specific to certain manufacturers, but can sometimes be applied generally.

With that in mind, truck owners can still stay out of deep trouble by watching the engine for changes in oil or coolant consumption, fuel mileage and performance.  

“An increase in active DPF regenerations on pre-SCR trucks can indicate that the filter needs service,” Moore points out.

“Owners can help prevent progressive damage to their aftertreatment systems through proper maintenance according to published intervals. If the EGR cooling system has performance issues, trouble codes will be present. Do not ignore them. Have the system fixed immediately to avoid more costly repairs,” Moore says.

While the diagnostic capability of contemporary engines is vastly improved over early models, owners should pay attention to the signals they are getting from the blinking lights on the dashboard. When a fault appears, pay attention to it.  

“The fault codes are historical, and all the faults are flagged,” says Clarke’s Dowling. “But good old-fashioned changes in performance or fluid consumption are still good indicators that something has changed. Don’t ignore them, either.”         

Comments

  1. 1. Tim [ February 12, 2014 @ 06:23AM ]

    What is considered normal regens? How many miles or hours are considered common on the Cummins engines this story was referring to?

  2. 2. BB [ February 12, 2014 @ 06:57AM ]

    We have 14 each 2010 Cummins ISX485's in our fleet of 80 trucks, they have more downtime than the rest of our fleet put together. 6 of them have needed complete rebuilds before 450,000 miles (carbon packing). ALL have had had at least 2 EGR coolers and 2 turbo's replaced, some as many as 4.
    When they get to around 4-500,000 miles, the Cummin's techs cannot keep them running over a couple of weeks at a time.

    I REALLY hope the new SCR motors are better, but I really just believe not enough miles have been accumulated yet (still too new) to show the problems. We only have 1 ea. 2012 (ISX w/ SCR) with about 315,000 miles, but it has already been in the shop way too much the last 4 months with about $20,000 spent on motor work.

  3. 3. Jim [ February 15, 2014 @ 08:34AM ]

    Normal engine regenerations should occur without you even noticing oftentimes. Their frequency will depend upon your driving style. If you're all highway, you won't require as many as if you're doing all in town driving .

  4. 4. Jesse [ February 15, 2014 @ 09:03AM ]

    We are generally talking about post 2006 DPF engines here, right? I've got a 2006 ISX with just the EGR/no DPF and the thing is bullet proof. I have had no MAJOR problems with any components related to the engine. 780,550 miles on it. Getting 6.25mpg in a regional operation hauling at gross 80% of the time. Am I lucky, or running on borrowed time?

  5. 5. BB [ February 20, 2014 @ 06:18AM ]

    Jesse,
    My comments only relate to DPF equipped motors (usually 08 trucks with 07 engines and newer). The DPF increases exhaust backpressure and this forces more and more exhaust gases, heat, etc. into the motor. All the parts and pieces that attempts to make this nightmare work seem to overwhelm both the engine and the Cummins techs that try to keep them running.

    You have a good setup, no worries!

  6. 6. Jesus [ February 20, 2014 @ 09:35PM ]

    I recently bought a VOLVO 08 that has already the DPF system. In the past, I used to lease a VOLVO 2012 and had thousands of issues with the REGEN process; now, Im scared as hell just by thinking to go through this funny party again. My truck has 631000 miles on it already and has a cummins ISX; is there any way to find out if the truck went through the proper mantainance when it comes to a REGEN issue?
    Thanks in advance for any advice
    Jesus Cruz

  7. 7. Cliff Downing [ March 01, 2014 @ 09:00AM ]

    When and if the OEM's find a way to drop EGR altogether and rely solely on SCR and DPF, a lot of problems, cost, downtime will be greatly reduced. You just can't feed either a living organism or an engine it's own feces and expect good results.

  8. 8. Nussbaum [ March 04, 2014 @ 04:13AM ]

    I have a 2009 Kenworth with a cummins and have had nothing but problems. At 65,000 miles the turbo went and DPF filter. at 75,000 miles the air compressor went due to carbon build up. At 170,000 the EGR Cooler went taking out the turbo and the DPF filter. A week later it was back in for ALL the injectors. In the last 45-days the truck cost me $ 17,000. This truck is down for repairs 75% more than its twin that is 2007 vintage.

  9. 9. catpower [ August 03, 2014 @ 12:26PM ]

    Cummins Isx what a joke

  10. 10. Debbie [ September 06, 2014 @ 12:35PM ]

    We bought our truck new 2009 Volvo with 485 Cummins ISX. We have had nothing but issues with our regen system since we got the truck. At just 7,000 miles we need a new particular filter. Then again at about 100,000 miles. At just over 330,000 miles the EGR Valve, EGR Cooler, Filter and Turbo we relplace. Six months later Turbo was replace again. With less than 100,000 miles we needed new compressor. We are on our 3rd one of those. The ERG Cooler failded within 130,000 miles. We have replace the 7th injector so many times I have lost track. We are on our 4th particulater filter. Just 2 months ago we had the filter cleaned. We have had and are still having problems with the system an NO ONE csn fix it or tell us ehat to do. All the techs just stab in the dark In 2013 we spent over $13,000 on the regen system. Our recurring problem since the last EGR Cooler failed is the truck will regen every 75 to 225 miles. If we are lucky we will go 300 miles without regening. But thst is so rare! I have talked to Cummins they said to stay away from Bio Diesel! We do our best but dometimes we have no choise. The above article even says ULSD is the only option. But yet the government is forcing Bio Diesel. hat do we do & WHO CAN FIX OUR TRUVK?

  11. 11. Douglas [ October 01, 2014 @ 05:56PM ]

    Debbie you may have a carbon packed engine. If you are having to regen that often the next time you have it serviced have them pull either the number 6 or number 1 injector and have them scope the cylinder. If the cylinder liners are polished, I.e. They have lost their cross hatch then you will need an inframe rebuild. Also have them check to see if you have fault code 3375 or 1921. If you have either one of them they will always point to having a rebuild through cummins eds. Hope this helps.

 

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