AdBlue Crystallisation (Urea Deposits)

Deposits often appear around the dosing injector, the filler neck or line connections. Crystals can block the dosing injector or the exhaust mixer. Leaks, very short trips and low exhaust temperatures encourage it. Small deposits at the filler can be wiped off with warm water. Deposits in the exhaust are removed by workshops.

AdBlue is a urea solution in water; when the water evaporates, urea remains as solid crystals.

Never add water, additives or substitutes to AdBlue; use only fluid meeting the ISO 22241 standard. A blocked dosing system can trigger warnings and, if ignored, a countdown that prevents restarting.