2014 International ProStar - Heavy DEF Consumption - No Codes

Question

I'm running a 2014 MaxxForce 13 and lately I've noticed I'm filling the DEF tank every single day. Usually, a tank lasts me 3 or 4 days. The weird part is I have no check engine lights, no codes, and no derate. Exhaust doesn't smell like ammonia particularly, and there's no white smoke.

I checked for leaks around the tank and the lines to the doser, but everything is bone dry. I'm confused as to where the fluid is actually going if the computer isn't complaining about high NOx conversion.

GrandmaGeartooth · Accepted Answer

✅ Confirmed fix: Discovered a small crack in the decomposition pipe where the DEF injector mounts. It wasn't leaking out; it was blowing the DEF spray directly onto the hot exhaust and evaporating instantly before it could react with the SCR catalyst. The NOx sensors were still reading 'acceptable' enough to not pull a code, but the pump was working overtime to compensate. Patched the pipe and usage returned to normal.

ShopForemanShane · Answer

Check your coolant levels. Sometime the DEF heater lines leak internally into the tank, but that usually causes a code for quality. If you're physically losing fluid, check the injector nozzle spray pattern.

2014 International ProStar - Heavy DEF Consumption - No Codes

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