I have been following a thread recently on duramaxforum.com which is following people that have had DEF problems with their 2011 and newer chevy duramax trucks. I happen to be one of them. My truck is in the shop for the second time, first time they replaced the NOX sensor. 300 miles later it is back in for DEF issues and I won't know something til next week. I was wondering how wide spread it was because it is a 36 page thread and growing on duramaxforum. I would like to hear from anyone on here that has the DEF version Duramax and whether or not you have had any problems. I was thinking maybe we could post here what your year your DEF duramax is and whether you have had problems or not, and the mileage of such problems or hopefully the mileage of trucks with no problems. I am trying to figure out if I should keep this truck or not.ThanksI absolutely love this truck except when it breaks down!2011 duramax 24k CEL NOX sensor replaced300 miles later back in shop for DEF issue

A freinds kept going to the shop for def problems they finaly figured out he was getting bad def fluid

newman fulltimer wrote:A freinds kept going to the shop for def problems they finaly figured out he was getting bad def fluidI hope that is the real issue, from what I have read that's what they say in the beginning and it goes downhill from there.

Haven't had any problems yet with our 2012, but we only have a little over 11,000 in 1 1/2 years. I will keep a lookout for problems now that you have brought it up.

Had 44,000 Mi.+ on ours no problems?oh! was a 2011.There is a update that was run ours.

We purchased a 2013 3500 last spring. It now has 11K miles, no DEF issues.

Chevy Duramax DEF issues | Good Sam Community

Julie951
Explorer
Jun 14, 2024
I have a 2023 Chevy duramax and my truck is at 12,500 miles and in shop cause the def sensor just went out
- Grit_dog
  Navigator
  Jun 21, 2024
  Guessing no one that replied 19 years ago cares.
  - naturist
    Nomad
    Aug 12, 2024
    Just guessing that those prescient enough to have replied ten years before the original post would have also anticipated Julie951's post.
Dayle1
Explorer II
Jan 16, 2014
My truck has less than 1400 miles on it, so haven't added DEF yet. But there has also been a lot of discussion about the shelf life of DEF. Based on the last 10 yrs of driving, I average about 8k miles per year and a full DEF tank might last me 7 months. Seems to me, why worry about the shelf life of an unopened jug and then let the fluid sit in the DEF tank for 6 months? So, I don't plan on filling it unless I'm headed out on a long trip. Otherwise, I will just add a gal. whenever the warning message appears. Time will tell.
nevadanick
Explorer
Jan 15, 2014
There was a bulletin issued for these trucks that said to add 3 gal of def when the dic said you have 1000 mi left so as not to overfill. This is what i do except i never get a 1000 mi warning instead its around 300 that i get the warning.
dave17352
Explorer
Jan 15, 2014
Well thank goodness it wasn't the DEF that made my CEL come on for the third time in a few hundred miles. The dealer just called and said it was a transmission code!! They will be working on it tomorrow morning. I will be interested to see what that is about.
hoopers
Explorer
Jan 15, 2014
N-Trouble wrote:
hoopers wrote:
2011 chevy, 35,000 miles.

One problem I have found, when filling up the DEF tank, is that its hard to get the last gallon or so of DEF into the tank, as it has trouble getting the air out of the tank, as the fluid is being poured in.

Try filling next time while parked on an incline. The filler and breather tubes are located on the front of the tank.

Thanks for the heads-up. Will try that next time.
N-Trouble
Explorer
Jan 15, 2014
hoopers wrote:
2011 chevy, 35,000 miles.

One problem I have found, when filling up the DEF tank, is that its hard to get the last gallon or so of DEF into the tank, as it has trouble getting the air out of the tank, as the fluid is being poured in.

Try filling next time while parked on an incline. The filler and breather tubes are located on the front of the tank.
campingken
Explorer
Jan 15, 2014
Reading things like this does cause me to think that our next truck will be a gasser. It would be terrible to spend $50,000+ on a truck that can tow most anything only to end up sitting parked on the side of the road.
gmcsmoke
Explorer
Jan 15, 2014
you're only supposed to add 5 gallons to an empty DEF tank. It needs to have room to freeze and 4500 miles is about right for 5 gallons of urea; usage is 1-1.25% of fuel used.
hoopers
Explorer
Jan 15, 2014
2011 chevy, 35,000 miles.

Several DEF issues:

-replaced sprayer nozzle
-multiple reprograms attempting to make my def last longer than 1200 miles. Dealer claims one must fill the whole tank up completely, or it doesn't reset itself correctly, whatever that means.
It seems to be fixed now, though I only get 4500 miles on my def tank. Decided not to worry about it anymore.

One problem I have found, when filling up the DEF tank, is that its hard to get the last gallon or so of DEF into the tank, as it has trouble getting the air out of the tank, as the fluid is being poured in.
Dadoffourgirls
Explorer
Jan 15, 2014
Click on my profile for my picture.