Coolant in the AdBlue tank
Coolant in the AdBlue tank means glycol in the dosing circuit. Glycol does not decompose to ammonia and it leaves a sticky residue through the pump and injector. Do not run the engine — call 01295 380724.
Ethylene or propylene glycol mixes readily with water, which sounds helpful and is not: it means the contamination distributes through the entire fluid volume rather than sitting as a layer you can drain off the bottom. Glycol is also thermally stable in the wrong way — dosed into a hot exhaust it does not break down cleanly to ammonia, it leaves deposits, and the corrosion inhibitor package adds its own residue at the injector tip.
Call 01295 380724 From just £89 call-out fee
Coolant in the AdBlue tank — the severity verdict
| Severity | Component risk Frequently needs SCR component work rather than a drain. Quoted before a technician travels. |
|---|---|
| What went where | Coolant in the AdBlue tank |
| Direction | Into the AdBlue tank |
| Typical cost | £280–£780 typical total, from a £89 call-out |
| Time on site | About 100 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 start the engine.
- Do not add AdBlue — because glycol mixes, dilution genuinely does not help here.
- Call 01295 380724.
What a technician actually does
Drain, repeat demineralised water flushing to chase the miscible contamination, AUS 32 flush, injector inspection, refill and code clearing. Injector or pump replacement quoted separately if the deposits are already established.
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
Coolant is water-based. Is that not better?
It is worse in one specific way: because glycol mixes with water, it spreads through the whole tank volume instead of settling where it can be drained off.
Will the dosing injector need replacing?
It is the component most at risk, because deposits form at the hot tip. Whether it needs replacing is assessed, not assumed, and quoted before the work.
Could this trigger the countdown?
Yes. Failed NOx conversion is what the system is watching for, and it leads into the same regulatory inducement sequence as an empty tank.
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
Work booked through AdBlue in Fuel is carried out by Fuel Fixer Ltd, company no 08520551, registered at Fairway House, Portland Road, East Grinstead, RH19 4ET, trading as Forecourt Assist and part of Fuel Fixer International, which is owned by Stockbridge Capital Holdings.
Reference: Selective catalytic reduction (Wikipedia).
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.