So my 2011 Volvo is not auto regenning. I started to tear into it a bit to see if I could find a problem. Low and behold, I find my exhaust is #### near plugged completely. No check engine lights, but I can tell its down on power a bit. Anyway, I am assuming this problem is either a faulty doser valve, or an air leak somewhere. any insights?
No. This is a clogged up def injector that is squirting instead spraying. Also if your temp sensor is not working right it will cause the system to over inject def.
Mine did that all the time. Takes a Crystal sublimation regen to get all that crap out. Its like concrete in there.
Build up like that is normal, just not to that extent. The normal build up is cleared out by doing a regen with crystal sublimation. You can't do it yourself unless you have Premium Tech Tool. It runs a regen at a hotter temp than normal and for about an hour and a half to vaporize all that. Of course you have an excessive amount that wouldn't clear after one regen anyway.
Otr performance sells a module that does the Crystal sub regen. Also resets a bunch of other stuff too. I recommend adding it to your tool box.
This is the reason for the heat blanket over the bellows that Volvo added to the scr trucks. Idling causes this buildup especially in cold weather. It would greatly benefit the emissions system if the entire canister and piping were blanketed. Heat keeps all this type of stuff from happening and helps the passive regen. I have added a turbo blanket on mine but have always wanted to try blanketing the canister and the flex pipe from turbo as well.
