Preventing AdBlue in a Diesel Tank in Llwynypia: Why It Happens

AdBlue in a diesel motor: two tanks, two fillers

Many modern diesels on the roads around Llwynypia and Blaen Clydach carry two liquids, not one. Diesel goes to your motor. Kept in a tank of its own, AdBlue is fed into your exhaust gas to clean it.

There's a filler on every tank. Some motors put the AdBlue filler in your boot or under the bonnet; plenty of others have both together behind one flap. Filling your diesel side at the pump goes on all the time. Someone who has to stop and think where it goes usually tops up the AdBlue side, from a bottle, and much less frequently. It is in the gap that the error happens.

Which filler is for AdBlue, and which for diesel?

Look at these before pouring, on a forecourt in Llwynypia or a driveway over in Pontygwaith. A few seconds, no more.

• Position misleads; the cap does not. AdBlue caps are often blue or bear the word "AdBlue" — diesel caps normally do not.
• Look at the size: the smaller filler neck is, on many motors, the AdBlue one.
• A label inside your fuel flap often says which fuel goes where, on plenty of cars. Check for it.
• The handbook says which it lives when the filler is not next to your diesel cap: your boot, or under the bonnet.
• Collecting a hire or company car, perhaps at the car park at the nearest station? Check with whoever drove the vehicle last before you set off, rather than once the light comes on.

What occurs when we turn up around Llwynypia

Wherever the vehicle has stopped, whether outside the local primary school, near Tonypandy Methodist Church or at home, our van travels to it. Both the work and the quote rest on three answers — which fluid, what amount, and whether it has run — so we ask. On the phone call itself, you are told the price — before anything else.

Emptying your tank comes next, followed by a thorough flush of your system. More than with petrol, it counts with AdBlue: the crystals build up, certain metals are attacked, and nothing clears out on its own, no matter how long it is left. Once the filter has been flushed — or renewed, where required — clean diesel goes in, and finally the vehicle gets tested. After that our technicians fire it up and confirm it runs correctly before leaving.

Most jobs are done in about half an hour once our engineers get there, as long as the motor has not run — and the pumps we use are fine on a live forecourt yet quiet at night outside a house. Paying happens on the day, not upfront, and you are given the documents an insurer asks for: an engineer report and a VAT invoice. While we travel, take a look at your insurance documents; many include cover for misfuelling.