--- title: Explained: AdBlue in a Diesel Tank Killywool canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/killywool-county-londonderry/ location: Killywool county: County Londonderry latitude: 55.013000 longitude: -7.103000 service: AdBlue in a Diesel Tank updated: 2026-10-22 --- # Killywool: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? AdBlue already in your diesel tank? In that case set this page aside a moment, leave the ignition and engine off, and call 0333 366 0103. Around Killywool, finding it before your motor turns normally means a drain and a full flush on the spot. Not happened yet? Below, the page covers the reasons it occurs and the how to prevent it for good. ## AdBlue in a diesel motor: two tanks, two fillers Many modern diesels around Ballykelly, as well as Killywool, run on two fluids; your engine takes just your diesel. AdBlue goes to the exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Every tank has one filler of its own. Under one flap, next to each other: that's the arrangement on many vehicles. Elsewhere, AdBlue's filler sits under the bonnet or in your boot instead. The diesel side is fuelled at the pump all the time. A driver who has to stop and work out where it goes normally fills the AdBlue side, from a bottle, and much less commonly. That gap is where the slip lives. ## Killywool: how AdBlue in your diesel tank takes place Carelessness rarely causes it. What does is three things lining up together. To start with, the warning. Low AdBlue brings a message from the car, and letting it run dry means limp mode — so a rushed top-up, perhaps before work off Crown Street, or outside the pub in the village on the way home that evening. The old car's filler is where your hand goes — but a rental car, a new car or a company car puts the fillers somewhere else. That is a second thing: an unfamiliar vehicle. A spout-topped bottle finds no obstacle at a diesel filler any more than at an AdBlue one. And so the tip, after started, keeps on. The same few seconds settle it, in the middle of Killywool or out in Greysteel. ## Which filler is for AdBlue, and which for diesel? Whether a Killywool forecourt or a drive over in Lettershendoney, spend a couple of seconds on these before anything is poured in. - Position misleads; the cap does not. AdBlue caps tend to be blue or carry the name "AdBlue" — diesel ones usually don't. - Look at the size: the smaller neck is, on plenty of motors, the AdBlue one. - Open the flap and check for a label — many cars show what goes in each filler just there. - The handbook. If your filler is not by your diesel cap, it's in your boot or under the bonnet, and the handbook says which. - The person who drove the car last. On a hire or company car collected from somewhere like the car park at the nearest station, ask before you leave, not when the light comes on. ## AdBlue top-ups that never reach the diesel tank A routine for the day the light comes on, wherever in County Londonderry that is. - Not in a rush on the side of Crom Street, not on a slope, not with your engine running: park then switch off first. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it works. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave the car on. - Using the bottle's own spout, pour slowly — and stop when it is full or the bottle is empty. - Only then, start the car: close the cap, check again, and make sure the diesel cap was never opened. Spot at step two or three that it's already gone into your diesel side? So stop just there. Don't go on to step five. ## Killywool: already put AdBlue in your diesel tank? Brief list, then. First: the motor remains unstarted. Leave the ignition off too, because on many diesels switching it on by itself runs the pump. Do not top up with diesel to dilute it: AdBlue doesn't mix with diesel, it sinks to the bottom of that tank, where the fuel is sucked from. Ask the staff to help roll your car clear of the petrol pump if you are on a forecourt — the the nearest petrol station, the another forecourt nearby or anywhere else. At home around Killywool? So your car stays where it is. Already run? Pull over once it's safe, then switch off. Killywool sits over 50 miles from the M77; there, use the next exit. Mileage counts — a quick hop across Killywool is a smaller job than driving under 10 miles to Derry — so say about how far it went. ## Killywool: what happens when we get there Our van comes to the vehicle wherever it has come to rest — your own driveway, near the centre, or by the local primary school. What liquid went in, the amount, and if it ran: our technicians ask because the replies decide the work and quote. You get that price on the phone, before anybody heads out. The system is then flushed thoroughly, after your tank is cleared. With AdBlue that matters 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 fuel filter is cleaned, or replaced where it needs to be; clean diesel goes in; and the vehicle is tested. We do not go until it has been started and is running properly. Most jobs are done in about half an hour once our technicians get there, as long as your engine hasn't run — and the pumps our technicians use are fine on a busy forecourt and quiet after dark outside a house. Paying is on the day, not upfront, and you are given the paperwork your insurer wants: an engineer report and a VAT invoice. Plenty of insurance policies include misfuelling cover, and so it's worth checking yours while we are on the way. ## About Killywool, for a moment Killywool is a small coastal locality in County Londonderry, situated near the city of Derry and overlooking the surrounding countryside from an elevation of 143 metres. Killywool is characterised by its predominantly detached housing stock and is close to nearby places such as Greysteel, Glack, and Eglinton. Killywool has a population of around 640 people and is located approximately 8 miles from Derry, making it a commuter base for the city. ## AdBlue drains around Killywool and across County Londonderry Killywool is a coastal area, and the vans that cover it also work the towns near it, Glack and Eglinton among them, across the BT postcode area. A postcode starting BT47 3 gets the van to you fastest. The vehicle remains where it is. We drain it where it is — a side street near a street just off the centre, a lay-by on the way to the green space at the edge of the village, a driveway. If you are near a boundary, or somewhere hard to describe like the back of the far end of the built-up part, ring and ask instead of assuming. ## Killywool drivers: the short version Tip no AdBlue till you've read the cap. AdBlue in the diesel tank regardless? Leave it switched off then phone 0333 366 0103; Petrol in Diesel empties it where it stands, across County Londonderry.