Threaded Mode | Linear Mode

RO285 · 03-24-2026, **(Subject: Trucks that sit with emissions intact )**

Forgive me if this topic has been covered. I looked but did not find anything specifically about this.

I've recently purchased a 2013 Freightliner M2 112 tractor with an ISL9 with very low miles, less than 24k, as an upgrade to an old 1987 truck. It's going to spend a lot of time just sitting, 3k miles a year maybe, and I am interested in how bad that is for the emissions system, specifically the def system. I have a pseudo mechanic telling me this thing will cost me as much as I paid for it in repairs if it isn't run hard and often. What kind of damage does sitting do to the emissions system and how might I mitigate it? If the truck is going to need repair for just sitting in a barn it might be for sale soon.

My thoughts were to keep the def pretty low in the tank to help keep it fresh. Other than that I'm not sure what can be done or if it is even a real issue. Appreciate your thoughts

hookliftpete · 03-24-2026, **(Subject: Trucks that sit with emissions intact )**

He is more or less correct. Run it at min monthly to avoid lot rot, if you are up to it get it demandated.

Rawze · 03-24-2026, **(Subject: Trucks that sit with emissions intact )**

The DEF system is the issue. It dries and crystalizes... and keeping the tank low for it is a death sentence.. as the inside walls of the tank, and therefore filters, injector, everything downstream etc.. will end up with crystallization clogging issues.

Keeping the tank absolutely full and topped off when it sits to help prevent drying inside the tank walls.

If I owned it then I would also run a 10% mix of some modern top brand of 80/90 gear lube in the engine oil system to prevent dry starts as well, but that is just me.

Same thing with the fuel system. Every time the windshield fogs up,. so does the inside of the fuel tanks. Keeping them topped off to full will prevent moisture buildup on the inner walls of the tanks, and therefore far less chance of algae buildup.

RO285 · 03-26-2026, **(Subject: Trucks that sit with emissions intact )**

I appreciate your thoughts on this. I was thinking the def "goes bad" not that the solution becomes more concentrated due to evaporation. I know this is mainly an ISX forum but can you point me to someone who can educate me on the demandate option for an ISL?

Rawze · 03-26-2026, **(Subject: Trucks that sit with emissions intact )**

(03-26-2026 )RO285 Wrote: ...can you point me to someone who can educate me on the demandate option for an ISL?

info: https://rawze.com/forums/showthread.php?...5#pid72945