--- title: AdBlue in a Diesel Tank Old Town? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/old-town-wiltshire/ location: Old Town county: Wiltshire latitude: 51.548340 longitude: -1.779480 service: AdBlue in a Diesel Tank updated: 2026-10-02 --- # Why It Happens and How to Avoid It: AdBlue in a Diesel Tank in Old Town Keep the motor and ignition off then phone 0333 366 0103 first — reading can wait if AdBlue is already in the diesel tank. A drain plus a full flush, done just where your vehicle stands in Old Town, is normally what it takes if found before your motor runs. Reading before the event? In that case what follows explains how it comes about and what to stop it happening at all. ## Why does AdBlue in a diesel motor need its own filler? Many modern diesels in North Wroughton, like those in Old Town, carry on two liquids; your engine gets 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 comes with one filler of its own. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. At the petrol pump, the diesel side is topped up constantly. Rarely filled, AdBlue usually comes out of a bottle, poured by someone who has to stop and think which cap it needs. It's in the gap that the slip lives. ## How does AdBlue in your diesel tank occur around Old Town? Three things tend to come together, and carelessness is rarely one of them. To start with, the warning. Low AdBlue brings a message from your car, and running out means limp mode — so a hurried top-up, maybe before work off Grovelands Avenue, or outside The Plough on the way home that evening. Unfamiliar vehicles are second, too. Hire cars, new vehicles and company cars put their fillers in new places, and habit reaches for the cap it used on the old one. A spout-topped bottle finds no obstacle at a diesel filler any more than at an AdBlue one. And so the pour, once begun, keeps on. Okus or the heart of Old Town: it takes the same few seconds either way. ## Telling the AdBlue filler from the diesel filler A couple of seconds is all the checks take — so run through them before you tip anything, on a driveway in Wroughton or a forecourt around Old Town. - The cap. The AdBlue cap is commonly blue, or marked "AdBlue". The diesel cap usually isn't. Read it instead of going by position. - Check the size: the smaller filler neck is, on plenty of vehicles, the AdBlue one. - Open the flap and look for a label — many cars show which belongs in each inlet just there. - The handbook shows which it is if your filler is not next to the diesel cap: the boot, or under the bonnet. - The person who drove the vehicle last. On a hire or company car collected from somewhere like the car park at Swindon, ask before you leave, not when the light comes on. ## Keeping AdBlue out of the diesel tank when you top up A routine for the day the light comes on, wherever in Wiltshire that is. - Stop on level, engine off, with time in hand — never rushing on the side of Bowling Green Lane. - Silly as it sounds, saying "AdBlue" out loud as you unscrew the cap does the trick — once you've found the filler and read the cap. - The two behind one flap? So make sure the lid on your diesel side is still closed ahead of lifting the bottle. - Gently does it, through the bottle's own spout, till it's full or the bottle runs out. - Before you start the vehicle, shut the cap and look a second time that your diesel cap never opened off. Discover during the second or third stage that the bottle went into the diesel tank? That is where you stop. Skip stage five entirely. ## Already put AdBlue in the diesel tank in Old Town? Brief order, then. Top of that: your engine stays unstarted. On many diesels the ignition alone runs the fuel pump, and so don't switch it on. Don't top up with diesel to dilute it: AdBlue does not mix with diesel, it sinks to the bottom of that tank, where your fuel is sucked from. Ask the attendants to help push the car away from the petrol pump if you are on a forecourt — the Harvest Energy, the Texaco or anywhere else. If you are on your own driveway in Old Town, leave the car where it sits. Stop as soon as it is safe then switch off, if the engine has already run. The next exit means the place to leave when you're on the M4, under a mile from Old Town. Tell us about how far it went: a run towards Oxford, under 50 miles away, is a bigger job than a short hop across Old Town. ## When our technicians arrive around Old Town, what takes place? Anywhere your car came to rest, whether by Lethbridge Primary School, near Westlecot Bowls Club or on your own drive, our van comes to it. Both the work and the quote depend on three replies — what liquid, which quantity, and if it has run — so our engineers ask. You hear that price by phone, before anyone heads out. Next: draining, then a full flush of the entire system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own — which is why the flush matters more with AdBlue than with petrol. After the fuel filter has been cleaned — or replaced, if needed — fresh diesel is added, and finally your car is tested. The motor is fired up next and checked to make sure it runs properly, all before our engineers leave. Most jobs are done in roughly half an hour after we arrive, provided your engine hasn't run — and the pumps our engineers use are safe on a live forecourt yet quiet at night beside a house. Paying is on the day, not upfront, and you receive the documents an insurer asks for: an engineer report and a VAT invoice. Before we get there, have a look at your insurance documents; many carry cover for misfuelling. ## About Old Town Old Town is a suburban area in Wiltshire, situated inland at an elevation of 146 metres, with terraced housing being the predominant type of accommodation. Old Town lies approximately 26 miles from Oxford and 71 miles from London, placing it within commuting distance of these major cities. Old Town is surrounded by other nearby places, including Okus, Wichelstowe, and Walcot West, and has a population of around 6330 residents. Old Town forms a distinct community within the wider area, with its own character and amenities. ## AdBlue drains in Old Town and across Wiltshire Old Town is a residential suburb, and the vans that cover it also work the places near it, Wichelstowe and Walcot West among them, across the SN postcode area. A postcode starting SN1 4 gets the van to you fastest. The car remains put. The drain takes place right there, whether a drive, a road near Earth, or a lay-by towards Sunken Garden. Assuming doesn't help at the back of Town Gardens Bowl, on a boundary, or somewhere hard to describe; ring and check. ## Old Town motorists: the short version Before you tip, read the cap. If AdBlue has gone in the diesel tank anyway, leave the car off then ring 0333 366 0103. Petrol in Diesel empties it where it sits, anywhere in Wiltshire.