Expired AdBlue
Expired AdBlue degrades as urea slowly hydrolyses to ammonia, so the concentration drifts out of specification and the system under-doses. It is one of the cheaper faults to put right — drain, flush and refill. Call 01293 248666.
Urea in solution is not indefinitely stable. It hydrolyses slowly to ammonia and carbon dioxide, and the rate rises sharply with storage temperature — which is why manufacturers quote shelf life against a temperature band rather than a flat date. Fluid stored warm for a long period, or in a part-used container that has been opened repeatedly, drifts below the 32.5% concentration and can also develop elevated biuret. The result is quiet under-dosing rather than any dramatic symptom.
Call 01293 248666 From just £89 call-out fee
Expired AdBlue — the severity verdict
| Severity | Recoverable Normally put right by a drain and flush, provided the engine has not been run. |
|---|---|
| What went where | Expired AdBlue |
| Direction | Into the AdBlue tank |
| Typical cost | £150–£330 typical total, from a £89 call-out |
| Time on site | About 55 minutes |
| Call-out | From just £89 call-out fee |
| Helpline | 01293 248666, 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
- Check the date and the storage conditions on any container you still have.
- Do not top the tank up with more old fluid.
- Call 01293 248666 if the system has already logged a fault.
What a technician actually does
Drain, flush, refill with in-date certified fluid, and clear any stored NOx conversion or fluid-quality codes.
Why this is not the same job as the other direction
This is contamination of the SCR dosing circuit — tank, metering pump, heated lines, dosing injector and potentially the catalyst. It is not the fuel system, and it is not the cheaper job. Anyone quoting a flat drain price for this has not looked at the system.
Common questions
How long does AdBlue last?
Manufacturers quote shelf life against a storage temperature band rather than a single figure — typically around a year at moderate temperatures, less if it has been stored warm. Check the container.
Does freezing ruin it?
No. AdBlue freezes at about −11 °C and thaws back to specification without harm. Vehicle tanks and lines are heated for exactly this reason. Freezing alone does not spoil the fluid.
What are the symptoms of old fluid?
Usually nothing you can feel — a dosing or NOx conversion fault appears, often after several driving cycles.
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
AdBlue in Fuel is a service by Forecourt Assist. 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. Fuel Fixer International is owned by Stockbridge Capital Holdings.
Reference: GOV.UK — MOT emissions rules.
Across the Fuel Fixer network
Every brand above belongs to Fuel Fixer International, owned by Stockbridge Capital Holdings. The directory lives on the operator's own site: forecourtassist.co.uk/network.