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Hello,
What are the typical scenario’s that a Dpf or Scr would fail,i could imagine a low load cruising condition would cause the dpf to clog and regen the system more then if the vehicle was under a high load condition most of its life.Iam sure there’s alot of different scenarios to consider but any input or articles to read on this issue is appreciated.
ThanksThe DPF traps soot and the worst-case operating regime for a Diesel engine creating soot is rapid acceleration. This is because when the “gas pedal” is depressed rapidly, the engine controller lets the engine run richer than normal for a short while to let the turbo spool-up as quickly as possible. In the old days, you would actually see black smoke at the tailpipe; today the engine doesn’t go that rich (and the DPF traps any soot), but these increasing load transients create the most soot of any operating regime for a modern Diesel engine. So to minimize the frequency of regenerating the DPF, try to do your acceleration as smoothly and gently as possible. Avoid stabbing the throttle pedal. The other way to avoid actual regeneration is to drive at very high power levels for an extended period of time to get the exhaust hot enough to passively regenerate the trap. Driving up a long grade at high speed should do it. Low load cruising should be pretty easy on the DPF because the soot output of the engine should be quite low. The downside of light loads is that the catalysts cool off and none of the soot is burned-off.
When a DPF regenerates it burns the soot off, but the soot leaves a little bit of ash behind and eventually the DPF will have to be cleaned or the engine back-pressure (from the ash clogging the DPF) will hurt performance and fuel economy.
The SCR catalyst should never clog up, but the SCR system uses an injector (like a fuel injector) to spray the Diesel Emissions Fluid (DEF) on the SCR catalyst substrate. This consumes the stored NOx emissions. The most unreliable part of the SCR system is going to be the injector and pump because it has to exist in a relatively harsh environment. NOx accumulation tends to be roughly proportional to engine power level.
Ok wow I wouldn’t of thought that interesting,I’ve been looking at diesel trucks to purchase like a 2018 ram 2500 people on those forums were saying to completely remove the system which can carry a hefty fine but increases reliability ,or some were suggesting that a aftermarket tuner with the system in place would make the truck more reliable.i just couldn’t imagine how a aftermarket company through tuning could make the system more reliable.i just want the truck to run and not worry about it I was thinking maybe going pre 2008 just so I could ditch the entire dpf,scr problems.
You can’t really get away with removing the emissions systems in states with inspection laws and with vehicles with OBD-2 that will light the Check Engine light. I am not a big fan of the aftermarket tuning companies because they typically allow lots of smoke in their calibrations. You can get better performance with some of these aftermarket cals. The SCR systems went into production around 2010. In general, I would not buy a modified used Diesel truck.
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