Duramax and Blue Def

SDM wrote:
I had to replace both nox sensors at around 40,000 miles. They were covered under warranty. The GM dealer asked what def fluid I was using. Had been using Blue Def from Walmart, he said that Blue def was causing problems with the sensors and recommend either GM or Flying J. Has anyone else had good or bad results?

Nonsense. The Peak Blue DEF meets all the requirements set by GM.

Been using Peak Blue DEF from day one and no issues. 72,000 miles. 2011 Chevy 2500HD CC4X4(LML)

Late
Roger

JustLabs wrote:

SDM wrote:
I had to replace both nox sensors at around 40,000 miles. They were covered under warranty. The GM dealer asked what def fluid I was using. Had been using Blue Def from Walmart, he said that Blue def was causing problems with the sensors and recommend either GM or Flying J. Has anyone else had good or bad results?

Nonsense. The Peak Blue DEF meets all the requirements set by GM.

^^^^This!!

What the dealer told you is COMPLETE BS. Both GM and Ford has been having problems with their sensors. More than likely they are from the same off shore vendor. :R

RADROG wrote:
Been using Peak Blue DEF from day one and no issues. 72,000 miles. 2011 Chevy 2500HD CC4X4(LML)

Late
Roger

PHEW :R !!! makes me feel a whole bunch better! Thanks! I'm using the Wall Mart brand too.

If you were buying it from a guy walking around a truck stop with a jug full of yellow liquid he's selling as Urea, you'd have a problem. All real DEF is made all the same - it's clear with 32.5% Urea and 67.5% deionized water.

+1 been using Blue on/off for 40K miles and no problems. Dealer just wants you to buy their overpriced DEF which likely comes from the same factory. Go figure.

Is you truck by chance a 2011 model? They had a lot of NOx sensor issues on the first year LML trucks and not because of inferior DEF. Simply bad sensors...

When the poor quality DEF message appears, they (GM) didn't provide a drain either. Been there and had to take the truck to the dealer to get the message deleted. The fluid was well within the age requirements also.

Next time ask him to put in writing, on company letter head...and sign it

Better yet, on the work order & sign it

worked on a ram 2500 for a def problem the other day done all the checks on the def fluid ,checked ok called chrysler star asked me if any thing floating in fluid, there was none told me scr converter bad (having problems with early failuer) replaced scr all went ok . But i asked this question only because the fault code i got was for degraded def, the guy used brand from wal-mart chrysler told me all def fluid is the same no matter what brand. But he did tell me what is happing is people have figured out how to beat the system by adding dishwashing soap he didnt know the amount(or he couldnt tell me) that is why he asked me if anything floating in it or if it was slightly cloudy.

99.99% of the time on 2011 GM trucks the "Poor Quality DEF" message is due to faulty NOx sensor and not actually the quality of the DEF. There are countless reports of this over on the Dmax forum. Later model years can also happen but they seem to be in much smaller numbers.