2010 maxforce 13 will not do passive regen.

Got home a week ago, truck started a regen while driving through my subdivision, I parked it without further driving. Truck was parked for a week while I replaced hp turbo and updated oil line. When finished, I drove her about 50 miles. Today I drove24 miles from my house to the terminal, 33 miles to my pickup, which she started a regen about a mile from my stop, exhaust temp light was on. Dropped my trailer, hooked to another, drove 20 miles and dpf went straight to flashing with alarm. Should I have kept driving in the two earlier events?

 

Sounds like too much stop and go. Every time you go through the gears a little puff of black smoke goes into the DPF. With stop and go the exhaust hardly gets a chance to get up to temp. Regen will be constantly starting and stopping. The only regen light you can drive through is level one, solid light only. If you are at that point and you know you will not be constantly/consistanly on the highway, you should be pulling over and doing a parked.

 

Why does it go straight to flashing with alarm, bypassing first two steps? This is second regen in 200 miles!

 

The DPF filter is in need of cleaning. As I said before oil cloggs them up quick. When she jumps that fast between stages she is not getting the fliter below 3.0 resistance. Basically she will come out of a full regen and a few min later need another. This is the EXACT same thing my truck did when I had to replace the filter.

The ash is at capacity.

 

This sequence of straight to flashing with alarm seem to have started after hp turbo replacement?

 

Its only taking about 15min to complete?

 

The ECM is continuously recalculating soot load and it really doesn't nicely and gradually calculate accumulated soot build up because some engine running conditions produce little exhaust flow, like at low rpms and idle. The only way the ECM can accurately know how full the DPF is when running at sustained highway speeds. It can't see how full the DPF is getting because at stop and go and idling produce too little exhaust flow. During these times the DPF can be getting full , but it has been such a long time since the ECM has seen enough exhaust flow that it just guesses soot load. Now all of a sudden it is seeing very high DPF differential pressures it goes to level 3 right away. DPF diff pressure sensors do go bad, but generally when they fault the pressures they read are not physically possible and will set a code accordingly. I doubt changing your turbo has caused this.

 

Pressure differential sensor could be malfunctioning?

 

The one I drive was doing the same thing....going to Level 3 running 70mph loaded and then it would go away before finding a place to pull over. Finally it went straight to SEL/derate because the IH dealer we lease this unit from just dismissed my concerns so I figured when they had to tow it 150 miles grossing 73k they would be more diligent.

It got out of the shop Friday 13th and so far in two days no issues otber than DPF temp light comes on after running 75 miles loaded and pulling into drop yard to unload. Fingers crossed because this was always the first sign of trouble. I can't believe it would do this 5 out of 6 trips but we'll see how it goes.

 

What did they find?