Would you get it fixed?

naturist wrote:
DEF has nothing whatever to do with the DPF and the need or frequency of regenerations.
...............

That’s not quite accurate. There is an indirect relationship between DEF usage and DPF regen frequency. The pre-DEF Diesels that had DPF’s used a lot more EGR to cool the combustion temperatures, and control oxides of nitrogen. The downside to cooling the combustion temperatures is............more particulates for the DPF to catch. By using DEF as the primary means to control oxides of nitrogen, less EGR is needed, the combustion temperature can be maintained higher, fewer particulates are produced, and fewer regens are needed.

I owned one of those pre-DEF diesel trucks, and the most it ever went between regens was about 200 miles. Most of the time it was less than that, and sometimes a lot less. Like every 75 miles or so. My current truck’s miles between regens has slowly climbed since new to over 400 miles between regens. In fact it just recently went 500 miles between regens for the first time that I’m aware of, and started to regen even though the soot load was about 85%.

:):)

I was thinking something was wrong with the truck but today the DPF % full started rising and went from 5% to 30% over about 200 km so I guess the DPF is likely working properly. I don't know about the DEF.... maybe because it was so cold here all winter the DEF started out frozen and by the time it thawed the trip was over.

Unless you start losing fuel economy, power or a trouble code shows up I would just keep driving.

Most of the time the DEF gauges aren't very linear. In 10k miles of driving this year I went through 3 2.5 gallon boxes of DEF with my Duramax (starting full). I notice that I burn more on shorter trips or when towing.

My super duty has towed almost every mile. I poured in the 3rd 2.5 gal jug of DEF last week at 5,800 miles.

time2roll wrote:
Unless you start losing fuel economy, power or a trouble code shows up I would just keep driving.

This.

Without any diagnostic codes being thrown the mechanics are not going to have a clue what's wrong or how to fix it.

mkirsch wrote:

time2roll wrote:
Unless you start losing fuel economy, power or a trouble code shows up I would just keep driving.

This.

Without any diagnostic codes being thrown the mechanics are not going to have a clue what's wrong or how to fix it.

You're right and I think there is nothing wrong with it. I had my truck parked outside all winter and we had a very cold winter this past year. If the DEF was frozen at the beginning of each trip and if by the time the def tank thawed the the trip was about over it would explain why I didn't use much def. I turned my auto regen off and eventually my DPF % full started to climb. Once it hit 5% it didn't actually take all that long to reach 60% full. At 60% full I turned the auto regen back on and it immediately went into a regen. The regen cycle lasts for quite awhile longer after the % full gauge says 0%. So I think what was happening is that after completely cleaning DPF the 500 mile mandatory regen would take place even though the gauge was still reading 0% full.

Keep in mind most dealers will refill your DEF tank when you get an oil change, maybe that’s what is happening?

I did my own service. The last time the dpf did a regen was 336 km ago. Although the dpf % full screen got down to zero the burn may have got interrupted shortly after so it may not have actually burned completely clean. Anyway the dpf is already up to 40% after 336 km. It seems as though the engine might have been producing very little soot over the extreme cold weather we experienced this past winter. I don't know if that could make sense?