--- title: Explained: AdBlue in a Diesel Tank Portadown canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/portadown-county-armagh/ location: Portadown county: County Armagh latitude: 54.421030 longitude: -6.458240 service: AdBlue in a Diesel Tank updated: 2026-10-20 --- # Portadown: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? AdBlue already in your diesel tank? Then set this page aside a moment, keep your ignition and engine off, and phone 0333 366 0103. Normally, if your motor hasn't turned, it's drained and thoroughly rinsed where your vehicle sits around Portadown. Nothing happened yet? Below, the page covers the reasons it occurs and the ways to prevent it altogether. ## Two fillers, two tanks: AdBlue in a diesel motor Diesel feeds your engine — yet plenty of current diesels seen around Portadown and Broomhill hold another liquid as well. AdBlue goes to your 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. Plenty of motors have a single flap for both, while others put the AdBlue filler to your boot or under the bonnet. At the pump, the diesel side gets filled all the time. Seldom filled, AdBlue usually comes from a bottle, tipped by someone who must stop and think what filler it needs. Mistakes happen in that gap between them. ## How AdBlue in the diesel tank happens in Portadown Rarely is it carelessness: normally three things coincide. The warning comes first. As AdBlue runs low your car tells you, and if it runs out completely, your vehicle goes into limp mode. So the top-up is done in a hurry: on a drive off Heugh Road before work, or in the car park outside the pub in the village on the way home. Then the vehicle is unfamiliar. A hire car, a new vehicle or a company car puts the fillers where your last one did not, and the hand gets to for the cap it would have used on the old one. Third, the bottle fits: diesel filler or AdBlue one, it goes in as readily, and after the tip begins, nothing stops it. It takes a few seconds, be it out in Drumnacanvy or bang in the centre of Portadown. ## Telling the AdBlue filler from your diesel filler Look at these first, at a forecourt around Portadown or a drive out in Craigavon. Seconds, that's all. - Colour and marking: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap usually doesn't. Trust the cap, not where it sits. - Look at the size: the smaller neck is, on many vehicles, the AdBlue one. - Open the flap and check for a label — many vehicles show what goes in which filler right there. - In the boot or under the bonnet: that is where your filler is if it's not by your diesel cap, and the handbook tells you which. - Collecting a hire or company car, perhaps at the car park outside the nearest station? Check with the person who drove the car last before you set off, not once the light comes on. ## Keeping AdBlue out of the diesel tank when you top up For the day the light appears — wherever you are around County Armagh — a simple routine to use. - Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of South Crescent. - Locate the AdBlue filler, read the cap, and say the name "AdBlue" out loud while unscrewing it. It sounds silly. It does the trick. - The diesel cap remains on. When the two share a flap, confirm it is shut before lifting the bottle. - Using the bottle's own spout, pour slowly — and stop when it is full or the bottle is empty. - Before starting the car, close the cap and check a second time that the diesel cap was never opened off. Stop there if you find, at step two or three, that you've already poured into the diesel side. Never go on to step five. ## Already put AdBlue in the diesel tank in Portadown? Don't start your engine: that's how the short order of things starts. On plenty of diesels the ignition alone runs the fuel pump, and so don't switch the vehicle on. Diluting it with more diesel fails, since AdBlue sinks to the bottom instead of mixing — and that is where your fuel is drawn from. If you're on a forecourt, whether it is the the nearest petrol station or the another forecourt nearby, ask the attendants to help push your car away from the pump. Leave it where it is if you're on your own drive in Portadown. If the engine has already run, stop as soon as it is safe then switch off. Leave the M77 — over 50 miles out of Portadown — at the next junction. Roughly how far did it go? Crossing Portadown is smaller work than a trip of under 10 miles towards Armagh, and so say. ## Portadown: what happens when we arrive Wherever the car has stopped, whether outside the local primary school, near the centre or at home, the van comes to it. The replies determine this work and our quote, so we ask what got in, roughly how much, and whether it has run. Nobody heads out before you have had the quote over the phone. Next: a drain, then a thorough flush of the whole system. 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. Testing comes last: before that, fresh diesel goes in, and your filter is flushed or changed if necessary. Next our engineers start the car and make sure it runs smoothly before leaving. Unstarted cars usually need a half-hour job after the moment we arrive. The equipment is safe on a busy filling station, and hushed enough for a driveway after dark. The insurer will ask for an engineer's report and your VAT invoice, and you get both at the end. Payment is on the day, with no deposit. Plenty of insurance policies include misfuelling cover, so it's worth checking yours whilst we are on the way. ## About Portadown itself Portadown is a significant inland town situated in County Armagh, Northern Ireland. It lies on the banks of the River Bann, roughly southwest of Belfast. The town forms part of a larger urban area that includes nearby Craigavon and Lurgan. Portadown is nestled in the northern part of the county, making it a notable settlement in the region. ## Portadown and County Armagh: AdBlue drains across the area As a town, Portadown shares its vans surrounding areas — Scotch Street, Derryhale — all the way through BT postcodes and the surrounding area beyond. Quickest of all: quote a BT62 4 postcode for our van. Moving your car is not needed. The drain takes place on the spot, whether a drive, a street near a street just off the centre, or a layby on the way to the green space at the edge of the village. Assuming doesn't help behind the far end of the built-up part, close to a border, or somewhere awkward to pin down; ring and check. ## Portadown people: the short version Pour nothing until you've read the cap. Petrol in Diesel empties it on the spot, anywhere around County Armagh, if AdBlue has gone in your diesel tank anyway — and so leave the vehicle off then phone 0333 366 0103.