--- title: Ash Brake: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/ash-brake-wiltshire/ location: Ash Brake county: Wiltshire latitude: 51.601080 longitude: -1.801790 service: AdBlue in a Diesel Tank updated: 2026-10-22 --- # Why It Happens and How to Prevent It: AdBlue in a Diesel Tank in Ash Brake Keep the motor and ignition off then call 0333 366 0103 now — the rest can wait when AdBlue is already in your diesel tank. Normally, if the motor has not turned, it's drained and thoroughly rinsed where your car is in Ash Brake. Not happened yet? Below, the page covers the reasons it takes place and the how to avoid it altogether. ## AdBlue in a diesel car: two tanks, two fillers Many current diesels on the roads round Ash Brake and Haydon Wick 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 comes with a filler of its own. Plenty of cars have a single flap for the two, whereas some put the AdBlue filler to the boot or under the bonnet. Topping up your diesel side at the petrol pump happens all the time. The AdBlue side is fuelled far less frequently, usually from a bottle, and normally by somebody who has to stop and think where it goes. The error lives in that gap. ## How does AdBlue in the diesel tank take place in Ash Brake? Carelessness seldom causes it. Instead is three things coming up together. Haste comes from the warning. The vehicle warns you as AdBlue runs low, and an empty tank sends it into limp mode — so the top-up gets done in a rush, before work on a drive off Lady Lane, or heading home in the car park at Blunsdon Arms. The old car's filler is where the hand goes — yet a hire car, a new car or a company car keeps the fillers somewhere else. That is a second thing: a new car. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, and so nothing stops the tip once it has started. It's seconds, be it out in Abbey Meads or right in the heart of Ash Brake. ## Which filler is for AdBlue, and which for diesel? Before you pour anything, whether on a drive in Greenmeadow or a forecourt around Ash Brake, check these. They take a few seconds. - The cap. The AdBlue cap is regularly blue, or marked "AdBlue". The diesel cap normally is not. Read it instead of going by where it sits. - The size. On many motors the AdBlue filler neck is the smaller of the two. - Look inside your fuel flap: many vehicles carry a label there showing which fuel goes where. - The handbook shows where it lives when the filler is not next to the diesel cap: the boot, or under the bonnet. - Whoever had it before knows. Ask when you collect a rental or company car — at Swindon's car park, perhaps — rather than once the warning appears. ## Keeping AdBlue out of the diesel tank when you top up On the day the light comes on — anywhere it is around Wiltshire — a simple routine to use. - Turn off after you park — flat ground, engine stopped, and not in a rush by Sandstone Road at the roadside. - Locate the AdBlue filler, check the cap, and say the word "AdBlue" aloud as unscrewing it. It sounds silly. It works. - The two behind one flap? So make sure the lid on the diesel filler stays closed ahead of raising the bottle. - Stop when your tank is topped up or the bottle runs dry; before that, pour gently using the own spout. - Shut the cap, and check once more — making sure your diesel filler stayed shut the whole time. Only then, start the vehicle. Spot at stage two or three that it's already gone into the diesel side? Then stop just there. Step five stays out. ## Put AdBlue in your diesel tank around Ash Brake already? Then the order of things is short. Don't start the motor. Keep the ignition off too, since on plenty of diesels it by itself runs your fuel pump. Topping up with diesel will not thin it: instead, AdBlue drops to the base of the tank, just where the fuel is taken from. At a forecourt — Asda, BP or another — the attendants will normally help roll the car away, when you ask. Your own driveway in Ash Brake is where it should stay. If your engine has already run, stop as soon as it is safe and switch off. Ash Brake lies under 5 miles from the M4; there, use the first exit. Tell us roughly how far it went: a run towards Oxford, under 50 miles away, is a bigger job than a short hop across Ash Brake. ## What happens when our technicians arrive around Ash Brake Outside Bridlewood Primary School, near Groundwell Ridge Roman Site or on your own driveway: wherever your car has stopped, we come to it. The answers settle the work and our quote, and so our engineers ask what went in, roughly how much, and if it has run. Nobody sets off until you have had the price over the phone. After that: a drain, then a full flush of the entire system. Not like petrol, AdBlue forms crystals and attacks some fuel-system metals, and none of it clears away by itself. That is why it matters more. After your filter has been cleaned — or replaced, if required — fresh diesel is added, and finally your vehicle gets tested. Then we start it and check it runs correctly before we go. Using pumps fine on a working forecourt and quiet enough for use outside a house at night, most jobs in which your engine has not run need roughly half an hour after we arrive. No money in advance; you settle up that day. Afterwards, the VAT invoice and the report from the engineer go to you for your insurer. Plenty of insurance policies include misfuelling cover, so it is worth checking yours whilst we're on the way. ## About Ash Brake itself Ash Brake is a suburban area situated on the riverside in Wiltshire, with a mix of housing types but predominantly detached homes. Ash Brake sits at an elevation of 103 metres, within a short drive of nearby places such as Abbey Meads and Blunsdon St Andrew. Ash Brake is located near the city of Oxford, which is approximately 25 miles away, and is also within commuting distance of London, around 72 miles to the east. Ash Brake has a population of around 6949 residents. ## Ash Brake and Wiltshire: AdBlue drains across the area Ash Brake is a residential suburb, and our teams that cover it also work the towns near it, Blunsdon St Andrew and St Andrews Ridge among them, across the SN postcode area. Our van reaches you fastest with a postcode starting SN25 2. Your car stays put. Our technicians drain it where it is — a side street near Made in Swindon, a lay-by on the way to Ash Meadow, a drive. Assuming doesn't help at the back of North Swindon Library, on a boundary, or anywhere awkward to describe; phone and ask. ## The short version for Ash Brake drivers Before you tip, read the cap. Petrol in Diesel drains it on the spot, anywhere in Wiltshire, if AdBlue has gone in your diesel tank anyway — and so leave it off and ring 0333 366 0103.