Blocked AdBlue injector
AdBlue injector blocked — a blocked AdBlue dosing injector shows up as a dosing pressure fault and failed NOx conversion. Deposits at a hot spray tip rarely clear themselves. Cleaning is attempted first; replacement is quoted before it is done. Call 01295 380724.
The dosing injector meters a fine mist into the exhaust ahead of the catalyst, through a small orifice, at exhaust temperature. Anything that is not pure AUS 32 — mineral from tap water, metal impurity from uncertified fluid, insolubles from a dirty funnel — deposits there. So does urea itself, if the system repeatedly stops mid-cycle on short journeys. Once the spray pattern is disturbed the system either over-pressures or fails its conversion check, and logs a fault.
Call 01295 380724 From just £89 call-out fee
AdBlue injector blocked — the severity verdict
| Severity | Component risk Frequently needs SCR component work rather than a drain. Quoted before a technician travels. |
|---|---|
| What went where | Blocked AdBlue injector |
| Direction | SCR system fault |
| Typical cost | £180–£650 typical total, from a £89 call-out |
| Time on site | About 90 minutes |
| Call-out | From just £89 call-out fee |
| Helpline | 01295 380724, 24 hours |
£89 is the call-out. An AdBlue tank drain and flush is quoted on the phone before a technician travels. If the SCR system needs component replacement — dosing injector, pump, tank or catalyst — that is separate, and you will be told before any work starts. If this is a job we cannot fix at the roadside, we will tell you that on the phone rather than after we arrive.
What to do right now
- Do not keep clearing the code and driving — the dosing fault is protecting the catalyst.
- Have the fluid quality checked before anyone quotes for a part.
- Call 01295 380724.
What a technician actually does
Dosing pressure tested live, injector removed and inspected, cleaned where the deposits allow it, replaced where they do not — with the replacement cost stated and agreed before the part is ordered — and the spray and pressure verified afterwards.
Why this is not the same job as the other direction
This is an SCR system fault rather than a wrong fill, so the first job is reading the codes rather than guessing at a part. The same dashboard message covers a bottle of fluid and a catalyst.
Common questions
Can a blocked AdBlue injector be cleaned?
Sometimes, depending on the deposit and how long it has been building. Cleaning is attempted before replacement is proposed, and you are told which you are paying for.
Why did it block?
Most often fluid that was not certified ISO 22241, water that was not demineralised, or a contaminated container. Occasionally a pattern of short journeys.
Is this covered by the £89 call-out?
£89 is the call-out. The diagnosis and any drain are quoted on the phone; an injector replacement is a separate cost and you will know it before any work starts.
What customers say
4.8 out of 5 from 2,190 Trustpilot reviews. What reviewers mention most is that the technician stayed calm and professional with a driver who was embarrassed and stressed, and that somebody arrived when they said they would.
The most common criticism is price. People do not expect a wrong-fluid job to cost what it costs, and that is a fair complaint to publish rather than bury. The answer is the From just £89 call-out fee, a quote given on the phone before a technician travels, and being told when a job cannot be done at the roadside rather than after somebody has arrived and charged for the visit.
Related AdBlue problems
Start from a symptom instead
Where we cover
Who you are dealing with
This site is published by Forecourt Assist, which operates AdBlue in Fuel. Forecourt Assist is a trading name of Fuel Fixer Ltd, company no 08520551, registered at Fairway House, Portland Road, East Grinstead, RH19 4ET, a company of Fuel Fixer International. The group, Fuel Fixer International, is owned by Stockbridge Capital Holdings.
Reference: Selective catalytic reduction (Wikipedia).
Across the Fuel Fixer network
AdBlue in Fuel is a service by Forecourt Assist, a brand of Fuel Fixer International, owned by Stockbridge Capital Holdings. The full group directory is at forecourtassist.co.uk/network.