With all of the research I've done it seems most simple to clean DEF metering valve and add more DEF fluid first and see what happens.
That is the best DIY shot.
Don't know where you are wrt Memphis, but Memphis Autoworks (
https://www.bimrs.org/profiles/MemphisMW.html) is listed on
www.bimrs.org, and several other BMW shops are listed on
www.bimmershops.com -
https://www.bimmershops.com/search?q=tn
You seem to have relatively low miles, so it's not likely to be one of the more expensive problems (NOx, DEF tanks, SCR Catalyst). These problems are usually solvable for less than $1K, often less (the metering valve is around $500 or so to replace.)
It might also be the active tank's heater, which is repairable in the 328d (not in older models.)[/QUOTE]
THANK YOU for the link regarding the SCR system. I'm on mobile currently but later this afternoon I'll be around a computer and will download and study and potentially have more questions regarding what I understand/don't understand.
I'm glad I'm at least on the right page regarding my DIY fix. Question is, I cannot find and literature telling me where the metering valve is. I do not have the repair manual, but am ordering one... what did I say about hindsight? LOL So in the meantime I've found two forums regarding the metering valve but neither specified what vehicle. One said the metering valve is located on top of one of the DEF tanks and can be accessed from the trunk. The other I didn't quite understand as they said something about it being visible via engine bay, sort of near positive terminal. The trunk one makes more sense and I'll go look for it tonight, but would you have any guidance regarding location? Perhaps it's in the PDF you sent and this question will answer itself.
You mentioned the more expensive problems being solved for less than $1k. Where at? The independent shops? This is a genuine question. All of my researching has scarred me regarding pricing for the emissions system. I had read multiple scenarios where the car went to BMW and they just threw parts at it until they found the issue and the owner walked away with a $3k - $4k bill. I understand and respect that this isn't a cheap car, but there has to be more logic to it than that. I remember reading about one poor guy who had spent $3,800 at BMW and ended up just taking it for a tune and delete to solve the issue.
So that leads me to - during a potentially convoluted repair, how do you become your car's and your wallet'a best advocate? I assume thorough shop research, but do you discuss with the shop your budget restrictions and that part replacement needs to be as precise as possible? This is the first car I've owned that I may potentially need to bring to a shop so that's why I'm asking these dumb questions. Everything I've ever owned before were simple gasoline engines with nothing fancy and we've always just done the work ourselves. This is why I don't even know a good mechanic.. and like I said, I'm kicking myself for that.
That being said, thank you so much for that link to the BMW mechanics! There are actually a few within an hour of me, so I'll start doing some research to see who seems reputable and honest.
Thank you so much!
Here's another most likely painfully ignorant question - let's say I clean the metering valve, maybe even flush the tanks, and refill with DEF fluid and that does fix the issue. With the car remove the 200 mile 'til no start count down on its own or do I need to clear the codes? I don't currently have a code reader compatible with this BMW (so many lessons learned in such a short timeframe LOL) so I take it to my local auto parts store to read the codes and potentially clear them. When it threw these codes he tried clearing but they are "permanent" codes. There's another word for what they are but I just can't think of it. Essentially it was explained to me by another BMW enthusiast that the car runs 3 checks regarding nitrogen levels, and upon the 3rd pass if levels are still incorrect it throws the code and the code remains until the sensors detect normal levels. That being said, if I try to DIY the old girl and it does fix it, could the car potentially reset the codes on its own after 10 or so miles of driving? Or will I need to go get the codes cleared and potentially, if I fixed the issue, the codes will be clearable? I could potentially find this out myself but I do like to know what to expect, especially since joy riding to find out if I fixed something or not is extremely intimidating when I only have 160 miles 'til no start and I'd hate to have to tow the car to a repair shop down the road if this doesn't fix the issue. I truly wish there was a way to disable that count down so I didn't feel so pressured in my decision making! But oh well. Any thoughts or resources is super appreciated and thank you again.
So. Many. Lessons. Learned. Such is life, I guess!