(08-08-2019 )JKBowman Wrote: Thanks for the reply, Rawze. Hi, Hammerhead.
There's a lot to unpack here, but for brevity sake (I'll try) let me say that I've been following the advice I got from Chamberpains in this old thread.
I had new main bearings rolled in about 40,000 miles ago. At the time my mechanic inspected the DPF for packing and said that it looked good. He also inspected the top end and had a similar positive opinion on that. The owner of the shop literally went on to say, "A rebuild couldn't hurt, but at this point I think I'd just be taking your money." I was skeptical of that, especially given the number of miles, but my Blackstone report was also very positive. Without the money in my pocket for a rebuild and nobody willing to loan more than $15,000 toward it (despite good credit) there wasn't much left to do but keep driving and keep saving - or at least try.
I took her to Kenworth because 1) two independent shops had tried to diagnose the electrical problem with my bunk A/C and failed, 2) an engine light was on again (DEF Pump) and I'd already been in an small Wyoming shop for that, and finally 3) during my most recent tour, which I had just finished, I started to notice a minor coolant leak while not finding anything on the ground. I figured why not get it checked out.
Rawze, I suspect you may be right that taking the truck to KW was a bad business decision. It usually is. But I thought it was logical enough at the time. We were home. They were there. Downtime would be limited. I knew they had the wherewithal to fix my problems.
When the first quote came in, that one smaller than the final, it hit me in the gut but my wife and I both felt like the truck was worth saving. In retrospect, that may have been our biggest error. It may be that we shouldn't have tried to repair anything with anyone. Seriously. Maybe that should have been the end. But life goes on. This is where we are and I have to move forward.
First things first. I can't make any decisions or move forward with plans for anything until I figure out what's going on with this code. If anybody has any info on it, I sure would be thankful.
SPN:3216,FMI:20 = cummins fault code 3748. -> ftertreatment Intake NOx Sensor - Data Not Rational - Drifted High. An offset in the intake nitrogen oxide (NOx) sensor reading has been detected.
I.E.> A bad, leaking, or improperly installed NOx sensor at the back of the turbo... OR someone has replaced it with a fake sensor, or Chinese after-market one. It is basicly complaining that the sensor is not reading ZERO with engine off, during self test ... OR it is not changing at all when engine is revving up and down and under loads.
It will not clear this fault until you get the engine and exhaust 350+-F degrees, drive around a bit under varying conditions, and the self tests that were failing pass their checks again.
