--- title: Coedpoeth: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/coedpoeth-wrexham/ location: Coedpoeth county: Wrexham latitude: 53.052570 longitude: -3.068840 service: AdBlue in a Diesel Tank updated: 2026-10-17 --- # Avoiding AdBlue in a Diesel Tank in Coedpoeth: Why It Occurs If AdBlue is already in your diesel tank, stop reading for a moment: leave your engine and the ignition off then call 0333 366 0103. A drain plus a thorough flush, carried out right where your vehicle stands in Coedpoeth, is normally all it needs when found before the engine runs. The rest of this page explains why it takes place and how to make sure it does not — useful if you're reading ahead of time. ## AdBlue in a diesel motor, and its separate tank Many modern diesels on the roads around Coedpoeth and The Wern carry two liquids, not one. Diesel goes to your motor. Your exhaust, not your engine, is where AdBlue ends up: dosed into the gas to fresh them, from a separate tank. There's a filler on every tank. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in your boot or under the bonnet. Diesel gets filled on each filling station call-out, week in, week out. Far less commonly, the AdBlue side is filled — normally from a bottle, by a person thinking about where it goes. The mistake grows in the gap between the two. ## How does AdBlue in the diesel tank occur in Coedpoeth? Three things tend to line up, and carelessness is rarely one of them. Hurry follows from the warning. Your car tells you as AdBlue runs low, and a dry tank puts the vehicle into limp mode — so the top-up happens in a rush, before work on a drive off Heol Maelor, or on the way home in the car park at Five Crosses Inn. Then the vehicle is unfamiliar. A hire car, a new car or a company car puts the fillers where your last one did not, and the hand hits for the cap it would have used on the old one. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, so nothing stops the pour once it has started. It's seconds, whether out in Talwrn or right in the centre of Coedpoeth. ## How to tell the AdBlue filler from the diesel one Before you pour anything, whether on a drive in New Brighton or a forecourt around Coedpoeth, check these. They take a few seconds. - Where it sits misleads; the cap doesn't. AdBlue ones tend to be blue or bear the word "AdBlue" — diesel ones normally do not. - On many motors, the size tells: AdBlue gets the smaller filler neck. - The flap. Look inside the fuel flap for a label. Plenty of motors say there which fuel goes where. - The handbook. If your filler isn't by the diesel cap, it is in the boot or under the bonnet, and the handbook says which. - Picking up a hire or company car, say at the car park outside Gwersyllt? Check with whoever drove it last before you set off, rather than when the light goes on. ## Topping up AdBlue without it reaching your diesel tank A routine for the day the light comes on, wherever in Wrexham that is. - Switch off after you park — flat ground, engine off, and not in a rush by High Street on the verge. - Locate the AdBlue filler, read the cap, and say the name "AdBlue" aloud as you unscrew it. It sounds daft. It does the trick. - Leave the diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Gently does it, through the bottle's own spout, till it's full or the bottle runs out. - Close the cap and check again. Make sure the diesel cap was never opened. Only then start your car. Spot at stage two or three that it has already gone into your diesel side? So stop just there. Stage five stays off limits. ## Already put AdBlue in your diesel tank around Coedpoeth? Then the order of things is short. Don't start the engine. The fuel pump runs on many diesels as soon as your ignition is switched on — so leave it off. Don't top up with diesel to thin it: AdBlue does not mix with diesel, it sinks to the bottom of the tank, where the fuel is drawn from. The attendants at Asda, Esso or any forecourt will usually lend a hand pushing your car clear if you ask. Leave it where it is if you are on your own driveway around Coedpoeth. Stop as soon as it is safe and switch off, if the engine has already run. On the M53, under 15 miles from Coedpoeth, that means the next junction. Tell us about how far it went: a run towards Wrexham, under 5 miles away, is a bigger job than a short hop across Coedpoeth. ## Our arrival in Coedpoeth, and what takes place next By the local primary school, near The Salvation Army - Coedpoeth or on your own drive: wherever the car has stopped, our technicians come to it. Our engineers ask what was put in, roughly how much, and whether it's run, because the replies determine the work and our price. Nobody heads out until you've had our quote over the phone. Then the tank is emptied and the system flushed thoroughly. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own — which is why the flush matters more with AdBlue than with petrol. A test is last: before that, fresh diesel goes in, and your filter is flushed or replaced as needed. We do not go until it has been started and is running properly. Most jobs are done in about half an hour after our engineers get there, provided your motor hasn't run — and the pumps our engineers use are safe on a busy forecourt and quiet after dark outside a house. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. It's worth checking your policy as the van travels to you: misfuelling cover comes with plenty of policies. ## About Coedpoeth and where it is Coedpoeth is a village situated on the banks of a river in northeast Wales, approximately 3 miles from Wrexham. Coedpoeth sits at an elevation of 241 metres, overlooking the surrounding countryside. Coedpoeth has a mix of housing types, but semi-detached homes are the most common. Coedpoeth is located near other small villages, including Talwrn and Bryngwyn. ## AdBlue drains around Coedpoeth, and Wrexham beyond Coedpoeth is a village, and the vans that cover it also work the places near it, Bryngwyn and The Smelt among them, across the LL postcode area. Quickest of all: quote a LL11 3 postcode to our van. Your car stays put. Draining happens right there, be it a drive, a street by Coedpoeth Parish Hall, or a lay-by towards Memorial Park. If you are near a boundary, or somewhere hard to describe like the back of Coedpoeth War Memorial, ring and ask rather than guessing. ## For Coedpoeth people, the short version Always, the cap; after that, the tip. If AdBlue has gone in your diesel tank all the same, leave the car off then ring 0333 366 0103. Petrol in Diesel drains it where it waits, anywhere around Wrexham.