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

AdBlue in a diesel vehicle: two tanks, two fillers

Plenty of current diesels on the roads about Peebles and Kings Muir carry two liquids, not one. Diesel goes to the engine. AdBlue goes to the exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own.

Each tank has its own filler. Under one flap, side by side: that's the arrangement on a lot of vehicles. On others, AdBlue's filler is beneath the bonnet or in the boot instead. At the petrol pump, your diesel side gets filled all the time. The AdBlue side is topped up far less often, usually from a bottle, and normally by somebody who has to stop and think where it goes. It is in the gap that the error happens.

Which filler is for AdBlue, and which for diesel?

Before you tip anything, whether on a drive in Kings Meadows or a forecourt in Peebles, check these. They take a few seconds.

• The cap. The AdBlue cap is frequently blue, or marked "AdBlue". The diesel cap normally is not. Read it instead of going by where it sits.
• The size. On plenty of cars the AdBlue filler neck is the smaller of the two.
• The flap. Look inside the fuel flap for a label. Plenty of cars say there which fuel goes where.
• In your boot or under the bonnet: that is where the filler is if it's not by your diesel cap, and the handbook tells you which.
• Ask the person who drove it last — before you leave, not when the light comes on — when you collect a hire or company car from somewhere like the car park outside the nearest station.

What occurs when our technicians get there in Peebles

Anywhere the vehicle came to rest, whether outside the local primary school, beside Eastgate Theatre and Arts Centre or on your own drive, the van comes to it. Both the work and our price rest on three replies — which liquid, which amount, and if it has run — so our technicians ask. No one heads out until you've had the price over the phone.

The system is then rinsed thoroughly, once the tank is cleared. Much more than with petrol, it counts with AdBlue: the crystals build up, certain metals are attacked, and none of it clears out on its own, however long it sits. The filter is flushed, or replaced where it needs to be; clean diesel goes in; and the vehicle is tested. After that our technicians fire it up and make sure it runs smoothly before we go.

If your motor hasn't run, the majority of jobs take about half an hour once we are there, using pumps that are fine on a working forecourt and quiet enough to use outside a house after dark. Payment is on the day, not upfront, and you are given the documents your insurer wants: an engineer's report and a VAT invoice. Many insurance policies include misfuelling cover, so it's worth checking yours whilst we're on the way.