96bulldogpower Posted December 18, 2024 Share Posted December 18, 2024 Hey guys looking for help again on this one. Dealing with a 2012 granite with the mp7. The problem started when the dash requested a regen “SOON”. I tried to regen the truck with the dash switch and it would only raise the idle and drop after 3 seconds. I hooked it up to PTT and discovered spn3675 fmi7 for a fault on the turbo bypass valve. I diagnosed a faulty valve, replaced it and verified its function then it allowed me to properly start a regen. When it first started a regen the truck blew HEAVY gray smoke for a while, the regen lasted just over an hour when it was interrupted by the low fuel light. I quit that day and tried again today, filled the truck with fuel and tried another regen. Now the dash says regen “REQUIRED” I allowed it to regen and it lasted over 2.5 hours with no signs of stopping, I stopped the regen because I had to be out of the yard by a certain time. No codes are present, egt’s while regening are around 750° at their highest, differential pressure has now dropped to about .03-.06 but it still blows a little gray smoke while it’s in regen, on jpro it says soot level is at 48% and I can’t get it to drop, also truck is in low derate. I’m not sure how to proceed, anyone have any tips on what to do or check? I’ll attach a pic of my jpro screen. Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/ Share on other sites More sharing options...
fjh Posted December 18, 2024 Share Posted December 18, 2024 Not a guru on this however It sounds like you have a crack in the dPF there should not be any smoke! Think you need to pull it and inspect! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-564222 Share on other sites More sharing options...
steeler Posted December 19, 2024 Share Posted December 19, 2024 Exhaust temp is not high enough, and 260 degrees before cat? That can't be right.. When I have whacky exhaust temps I'm looking at 7th injector, face plugged cat, temp sensors... Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-564261 Share on other sites More sharing options...
The Heinz Posted December 19, 2024 Share Posted December 19, 2024 On 12/19/2024 at 2:35 AM, steeler said: Exhaust temp is not high enough, and 260 degrees before cat? That can't be right.. When I have whacky exhaust temps I'm looking at 7th injector, face plugged cat, temp sensors... Expand I just saw that, goes from 713° EGT to 260° at the DOC inlet, then up to 666° after DOC? Can't help but wonder if it's the temp sensor. Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-564268 Share on other sites More sharing options...
fjh Posted December 19, 2024 Share Posted December 19, 2024 fuel pressure cam be another issue with these ! how ever the smoke is not a good thing! the face plug idea is valid but usually a crack with this! Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-564273 Share on other sites More sharing options...
Popular Post 96bulldogpower Posted Thursday at 01:50 PM Author Popular Post Share Posted Thursday at 01:50 PM Sorry guys I’ve been absent from the site for a while, just wanted to follow up on my findings. a little background on the truck, we bought the truck originally inop from auction. Found it to have a bad PCM so we replaced it and the truck ran great. Fast forward a couple of months into service and we had this issue happen. The truck could never complete a regen. We eventually got the truck back to our shop where we could properly diagnose it. We removed the dpf to inspect it and found our problem, it had been hollowed out, the old pcm was deleted and we had no clue. We replaced all emissions components and reset parameters on PTT and life has been good since. Just figured this info could help someone in the future, if your truck never finishes its regens and all else looks good, take a look physically into your dpf. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-577055 Share on other sites More sharing options...
steeler Posted Friday at 08:58 PM Share Posted Friday at 08:58 PM I ran across one like that, hollowed out, but not deleted.... Go figure lol Quote Link to comment https://www.bigmacktrucks.com/topic/74876-2012-mp7-regen-will-never-end/#findComment-577118 Share on other sites More sharing options...
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