We are getting check engine light and limp home for the DPF clogged with soot. issue was occurring every 4 to 5 hours of run time, forced regen cleared the code and unit was returned to service. DPF was replaced, we went 500 hours and the issue returned, same code, limp home, forced regen, back in service. The repair tech says the engine needs replacement because at 23,000 hours it has exceeded the manufacturers recommended lifespan. I do not buy it. Any advice on where to go? The year of this machine is a 2018 Thanks
Depends on percentage of blow-by. DPF does not like oil.
Offhand I would say that is a huge number of hours. Does this thing work 2 or 3 shifts continuously since 2018? Does it ever see a good load or does it putt around the yard all the time? Does Ottowa have any advice about it?
Lots of idle time, three shift operation, each load moves about two miles and it must get up to 45 MPH for about a half mile.
I am hoping somebody more knowledgeable will chime in, but we use these on generator engines as well, and we figure that 1 hour roughly equals 35 miles of operation, so 23k hours would roughly equal 800k miles, seems to me like it served its time and now it is time for rebuild/replace, everything inside is probably worn slick, that is why the guy does not want to mess with it, fix one thing and then within a few weeks/months something else will go out and he might get blamed.
I think you covered it.
^ what they said. The CRs are not happy with all that idle time. Keep running it if you can, and it will start breaking rings that are carbon-backed. In farming terms, it has hoed it's row.
Somewhere in that computer there should be a total for the gallons of diesel burned. It would be interesting to see what the average duty cycle has been on this engine. I'd guess its pretty light. 35 mph for gen set engines? Sounds way to low to me even if they are unloaded stand-by. Unless you are running funny frequencies, those are hours at 1800 rpm. There again, fuel consumption would be useful.
Sounds to me like its burning oil and clogging the DPF. I wouldn't be suprised if the cylinder walls were polished smooth.
At 23k hours I would say it will be comprehensively Donald Ducked. Quite frankly I’m surprised that it has lived that long. Usually it’s only big engines that get to that sort of hours. As TH said have someone get into the electronic control and find out how many gallons/litres of fuel it has burned in its life so far.
Have you tried high idle instead of just idling?
The medium duty cummins are famous for having failed injectors which produce too much soot causing the dpf to plug early. Remove the exhaust before it enters the dpf and have someone floor the throttle. There should be a puff of smoke when the engine is revving up then clear at full throttle. Puffs of black or grey while at full throttle point to injector issues or air handling issues. Idling that much I would assume the grid heater is plugged solid with soot as well as the egr components.
Disconnect the crankcase ventilation if possible and measure crankcase pressure. Got an oil sample and analysis. Those hours are very high for that engine. Light load is actually detrimental to a diesel engine. They don't wear out from metal touching metal. The wear is caused by acidic compounds formed from incomplete combustion that settles on the walls of the cylinders. Lots of idling and light work shortens diesel engine life. You basically hit the jackpot on that engine.
^ it's why I caution anyone about buying a work truck out of the Dakota oil fields. Cold weather = too much idling. The miles might be low but if you dig into the display the hours are waaay whacked.
I said that right from the start, percentage of blow-by.
That is a number I have come to, from experience. I can equate the degree of "wore slap out" of a generator engine with the equivalent you would expect to see in a car with x number of miles. Usually the ratio is 35 mph, plus or minus a lot. Probably the fact that it runs for many hours at 1800 and never changes, is helpful.
Your comparison of "wore slap out" from a gen set to road vehicle seems as legitimate as it can get for two vastly different loading schemes.
I imagine it involved a few piles of parts and chickeneye. Wore slap out
We used a factor of 30 between off-highway equipment hours and on-highway engine miles. Like BV it was +/- a factor of quite a bit but it was generally pretty close.
This is the most recent report from the service contractor, this seems like what has been described here. Thank You all for your input. FOUND CODES FOR EXCESSIVE REGENERATION CYCLES AND LOW EGR FLOW REMOVED EGR DIFFERENTIAL PRESSURE SENSOR AND FOUND OILY SOOT ON EGR SIDE, CLEANED PASSAGES AND REINSTALLED SENSOR REMOVED CHARGE PIPE FROM TURBO, NO EVIDENCE OF OIL PRESENT RAN UNIT WITH OIL FILL CAP REMOVED, UNIT SMOKES THROUGH FILLER HOLE DUE TO COMBUSTION BLOWBY SUSPECT EXCESSIVE CYLINDER WEAR CAUSING INEFFICENT COMBUSTION AND EXCESS ENGINE SOOT PRODUCTION EXCESS SOOT PRODUCTION IS CLOGGING EGR COOLER AND CAUSING EXCESSIVE REGENERATION CYCLES TO CLEAR SOOT FROM DPF ENGINE HAS 23437HR, USEFUL LIFE EXPECTANCY IS AROUND 25K HOURS ENGINE IS NEAR END OF USEFUL LIFE AND NEEDS REPLACEMENT
Any oil field they all leave their trucks idling even in the summer, even not when cold. I've had conversations with a lot of people on how hard that is and nobody cares because it's not their truck. If anyone leaves one of my trucks idling all day they will be out the door that night.
This spotter has 9778 hours on it in the last two years, our cost per hour to maintain it is $17.21. If I do the math it is costing us $1613.00 per week to maintain this spotter. we want to replace this spotter the problem is how do we get through the 4 month lead time without having to replace the engine?
You do what you have to do. If it doesn't make it, then you replace the engine. It isn't rocket science and if you are the mechanic, it isn't your money to have to worry about.
Well colour me surprised - not.....
An ISB6.7 should flag the ECM for excess crankcase pressure. I know mine will, as will my ISX. While I've never seen it done on Cummins, my Duramax engines allow me to see injector balance rates. It has to be possible on Cummins, too. Balance rates off indicate poor injector performance, normally seen as over fueling. That would definitely lead to frequent, excessive regenerations.