Whiteholme: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It?

Why does AdBlue in a diesel car need its own filler?

Many newer diesels on the roads about Whiteholme and Norbreck carry two liquids, not one. Diesel goes to the engine. AdBlue's own tank keeps it, and from there it goes to the exhaust, where spraying cleans the gas.

Each tank comes with one filler of its own. Under one flap, next to each other: that is the arrangement on many vehicles. Elsewhere, AdBlue's filler is beneath the bonnet or in the boot instead. Filling your diesel side at the pump goes on constantly. The AdBlue side is fuelled far less often, usually from a bottle, and normally by a person who has to stop and think where it goes. That gap is where the mistake lives.

How to tell the AdBlue filler from the diesel one

A couple of seconds is all the checks take — so check them before you tip anything, on a driveway in Bispham or a forecourt around Whiteholme.

• The cap. The AdBlue cap is frequently blue, or marked "AdBlue". The diesel cap usually isn't. Read it instead of going by where it sits.
• On many cars, the size tells: AdBlue gets the smaller filler neck.
• Look inside your fuel flap: many cars have a label there saying which fuel goes where.
• Cannot find it beside your diesel inlet? In that case check beneath the bonnet or in your boot — the handbook will say which.
• Check with the person who drove it last — before you leave, not when the light comes on — if you pick up a hire or company car from somewhere like the car park at Poulton-Le-Fylde.

What occurs when our engineers get there around Whiteholme

Anywhere your car has stopped, be it outside Anchorsholme Primary Academy, near Sevenoaks Community Centre or at home, the van travels to it. Those answers decide this work and our price, and so our engineers ask what was put in, roughly how much, and whether it's run. You hear that quote on the phone, before anybody sets off.

Next: draining, then a thorough flush of the entire system. With AdBlue that counts more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own. The filter is cleaned, or replaced where it needs to be; clean diesel goes in; and the vehicle is tested. Then our technicians start the engine and make sure it runs correctly before we go.

Most jobs are done in about half an hour once we get there, as long as your motor hasn't run — and the pumps our engineers use are fine on a live forecourt yet quiet after dark outside a house. Nothing upfront; you settle up that day. Afterwards, a VAT invoice and the report from the engineer are handed to you for the insurer. Many insurance policies include misfuelling cover, so it is worth checking yours while we're on the way.