Shelf life of DEF fluid
I've read that DEF fluid doesn't have a very long shelf life so I was wondering about the fluid that's left in the coach tank during winter storage. Will it be okay for 3-5 months of storage or does...
Forum Discussion
Norskeman wrote:
Temp(deg F), life expectancy
32, Infinite
50, 75 Years
68, 11 Years
86, 23 Months
95, 10 Months
104, 4 Months
122, 1 Month
140, 1 Week.
I'm suspicious of the life at higher temps (95+). it wouldn't be hard to end up where the temp is 122 or higher much of the time if your in a desert climate especially driving during the heat of the day, and then park in an asphalt drive exposed to the sun.
And with GM they purge the def line whenever the engine shut down. you can hear the pump going on shutdown. probably to keep heat exposure down, and they also state that is to prevent any freeze damage in the lines. IIRC there is a heater to thaw out the DEF if it does freeze.
