Dpf temps

[Soulreaver0102]

(01-04-2020 )JimT Wrote:  So I just cleared up my own dpf issues. found a bad egr valve. for me it was causing exhaust temps to be too low resulting in occasional grey/blue smoke only while it tried to active regen. it also would cause the regen to end prematurely, which resulted in the "too frequent regen" code.

One other thing to check if you are smelling fuel during regen is the exhaust bellows connecting the back of the doser to the rest of the exhaust. they flex and wear out and when mine went this past summer it resulted in the same fuel smell you mentioned.

from that last picture you posted it looks like your getting a lot of incomplete regens. This was one of my problems prior to replacing the egr valve and doing the egr tune up. If the valve is still good and sensors are new then check to see if there's any wiring problems. broken, dirty or corroded wires and connections could lead to bad sensor readings that halt the regen in progress.

for me, finally replacing the EGR valve (after an EGR tune-up and new bellows) is what got things regenning properly. and no, I never had any egr related codes to tip me off either.

side notes:

EGR valve.
When I inspected the EGR valve i first noticed excessive soot coming out of the weep hole on the back side. Quickserv says some soot is normal, but this looked excessive. next when looking inside both sides had a fine, dry and thin layer of soot build-up and the valve appeared to be closed. disregarding the instructions in quickserv/insite I LIGHTLY pushed the valve open. it had almost no resistance and did not close at all. It also left a trail in the soot build-up that hadn't been there before.

Doser.
6 months ago I removed and cleaned the dpf doser. build-up wasn't bad but I noticed the thermal isolator was thin and compressed in to a hard disc. cleaned off the doser but didn't replace the thermal isolator at the time (didn't have one on hand). fast forward to now, pulled the doser 6 months later and it was caked up with soot pretty good. this time I replaced the isolator and the new one was twice as thick and less dense than the old one was. I suspect that it's condition contributed to the rapid build-up in only 6 months. lesson learned: regularly check the doser for build-up, regardless of how new it might be. (my doser had been replaced 18 months ago when i bought the truck)

I appreciate it. That will be my next move for sure.