Why AdBlue crystallises
AdBlue is about one-third urea dissolved in water. When it evaporates — at the injector tip in hot exhaust, at a weeping joint, or in a system that has stood unused — the urea is left behind as hard white deposits.
Short journeys, stop-start delivery work, vehicles that stand for weeks (motorhomes especially) and small leaks all make it worse.
Signs your system is crystallised
- White crust around the AdBlue injector on the exhaust
- White deposits around the filler neck, pump or tank connections
- SCR efficiency or dosing faults such as P20EE or P20E8
- A countdown or warning that returns soon after being cleared
What we check and how the job works
We read the fault memory, run a dosing quantity test, check pump pressure build and inspect the injector and lines. Where the injector is only blocked, cleaning and re-testing it is often enough.
If a component has been damaged — a cracked injector, a failed pump — we show you the test result first. Send the registration and dashboard message by WhatsApp to get started.
Keep reading