Hate to tell you all, but this problem never ends. My sprinter has been in the shop 10 times for the DEF system.
Everyone whom is guessing ‘bad def” or “old def” caused the problem are completely wrong and really shouldn’t be “guessing” on a
forum on an important issue like this. The issue is a defective design from
Mercedes. Period. Guess where my Sprinter is right now? In the shop having $3,000. Worth of DEF work
done, following $3,500. And $2,200. In DEF repairs and all of the days when it was under warranty. Every time I’m
in a Mercedes shop, waiting to spend thousands to replace def parts, again, I meet others who are there
for the same reason. I’ve also met those who blew their engines by trying to bypass the system.
So, this problem is a defective design. No one did anything to make their systems break. And, people
who are sharing “guilt” by guessing what we did to break our systems are really not helping.
So, if you don’t know what you are talking about, please don’t “guess.”
You add nothing to the discussion by guessing and blaming whatever or whomever.
Mercedes should replace all these but that would cost billions. So, we owners suffer.