Regen (Regeneration) is when the DPF (Diesel Particular Filter/Exhaust Filter) is cleaning it's self. There are two type of regens
1st is Passive. Your truck is always doing this. But temps must be hot enough to be effective. Maintaining RPMs above 1500 is ideal.
2nd is Active. When your truck is dumping raw fuel during the exhaust stroke on cylinders 7 & 8 making the exhaust gases hotter effectively burning the soot in the DPF. Truck performance is limited during this time. Some guess by 50-100HP and exhaust gasses can exceed 1300F. When my truck regens, I can feel it immediately.
Stop and go traffic is not good for the regen process. The lower exhaust temps allow the DPF to clog faster requiring more active regens. Note each time you do regen. The distance between regens should be between 250-600 miles and could last from 1-20 miles all dependent on the state of the DPF. If your regening much more than that or for longer distances then you may have a problem. * The numbers I added are "soft" numbers as every truck is different.
The wrong type of oil can also cause DPF failure. Stick with CJ-4 rated oil as your truck was designed to use..
Do you have oil in the tail pipe? Could be turbo seals, burnt valve, piston rings...
Last edited by DisposableHero; 09-20-2013 at 11:13 AM.