--- title: AdBlue in a Diesel Tank Wallisdown: Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/wallisdown-dorset/ location: Wallisdown county: Dorset latitude: 50.748760 longitude: -1.922600 service: AdBlue in a Diesel Tank updated: 2026-10-22 --- # Wallisdown: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? Pause here a minute when your diesel tank already holds AdBlue in it: ignition off, engine off, and ring 0333 366 0103. In Wallisdown, finding it before the engine runs usually leaves a drain and a full flush on the spot. If you're reading before it has happened, the remainder of this page is about why it occurs and how to make sure it does not. ## AdBlue in a diesel motor, and its separate tank Not one liquid but two: that's what many modern diesels around Wallisdown and Rossmore run, with diesel for the engine. Your exhaust, not your engine, is where AdBlue goes: sprayed into the fumes to fresh them, from its own tank. Every tank comes with one filler of its own. Plenty of vehicles have a single flap for both, while some put the AdBlue filler to your boot or under the bonnet. The diesel side is filled at the petrol pump all the time. Much less regularly, the AdBlue side is filled — mostly from a bottle, by a person thinking about where it goes. The mistake grows in that gap between the two. ## AdBlue in your diesel tank around Wallisdown: how it takes place Rarely is it carelessness: usually three things coincide. Hurry comes from the warning. The vehicle tells you as AdBlue runs low, and an empty tank puts it into limp mode — so the top-up gets done in a rush, before work on a driveway off Raleigh Road, or heading home in the car park outside Kings Arms. The old car's cap is where your hand goes — yet a rental car, a new vehicle or a company car keeps the fillers elsewhere. That's a second thing: a strange vehicle. No part stops the pour once it has started, since a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. The same few seconds settle it, in the middle of Wallisdown or out in Turbary Common. ## How to tell the AdBlue filler from the diesel one Check these before pouring, on a forecourt in Wallisdown or a drive out in Bourne Valley. Seconds, no more. - Check the cap rather than going by position: AdBlue caps are often blue or marked "AdBlue", and diesel ones usually are not. - On many cars, the size tells: AdBlue gets the smaller filler neck. - Look inside the fuel flap: many vehicles have a label there showing which fuel goes where. - 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. - Ask the person who drove it last — before you leave, not when the light comes on — when you pick up a hire or company car from somewhere like the car park at Branksome. ## Keeping AdBlue out of the diesel tank when you top up Anywhere in Dorset the light comes on, this is a routine for the day. - Not in a rush on the side of Frobisher Avenue, not on a slope, not with your engine running: park then switch off first. - Say "AdBlue" out loud as you unscrew the cap, after finding the AdBlue filler and reading it. Daft, perhaps, yet it does the trick. - Both behind one flap? Then make sure the cap on your diesel side stays shut ahead of raising the bottle. - Using the bottle's own spout, tip slowly — and stop when it's full or the bottle is empty. - Before starting your car, shut the cap and look again that the diesel cap never opened off. Discover at the second or third stage that the bottle went in the diesel filler? That's where you stop. Step five is off limits. ## Put AdBlue in your diesel tank around Wallisdown already? What follows is a short order of things, starting with no starting your engine. The fuel pump runs on many diesels the moment your ignition is switched on — so leave it off. Do not top up with diesel to thin it: AdBlue doesn't mix with diesel, it sinks to the bottom of your tank, where your fuel is sucked from. Ask the attendants to help push your car clear of the petrol pump if you are at a forecourt — the BP, the Sainsbury's or somewhere else. On your own drive around Wallisdown? Then the car remains where it is. If your motor has already run, stop as soon as it is safe then switch off. On the M27, under 25 miles from Wallisdown, that means the next exit. Tell us about how far it went: a run towards Salisbury, under 25 miles away, is a bigger job than a short hop across Wallisdown. ## When we arrive around Wallisdown, what occurs? Outside Manorside Academy, near St Saviour or on your own driveway: wherever your car has stopped, we come to it. What fluid got in, the quantity, and if it ran: our technicians ask because those replies set both work and price. You get that price on the phone, before anyone sets off. The system is then flushed thoroughly, once your tank is emptied. With AdBlue that counts 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. A test comes at the end: before that, clean diesel is added, and the filter is cleaned or changed if necessary. We do not leave until it has been started and is running smoothly. Most jobs are finished in about half an hour once our engineers arrive, provided the motor hasn't run — and the pumps we use are fine on a busy forecourt yet quiet at night outside a house. Payment is on the day, not upfront, and you are given the documents an insurer wants: an engineer report and a VAT invoice. Before we get there, have a look at your insurance documents; plenty carry cover for misfuelling. ## About Wallisdown itself Wallisdown is a suburban area in Dorset, situated near the coast and characterised by detached housing. Wallisdown sits at an elevation of 56 metres, overlooking the surrounding landscape. Wallisdown is located near Turbary Common and other nearby places such as Alderney and West Howe, and is within commuting distance of Salisbury. Wallisdown has a population of approximately 3945 residents. ## AdBlue drains about Wallisdown, and Dorset beyond As a residential suburb, Wallisdown has the same vans as nearby places — Alderney, West Howe — all the way across BH postcodes and the wider area beyond. Fastest of all: give a BH12 5 postcode for the van. Moving the vehicle is not necessary. Wherever it sits — beside TeamSport Bournemouth, on a lay-by en route to Turbary Common Local Nature Reserve, on a drive — that is where it is emptied. If you're close to a border, or somewhere hard to explain like the back of TK Maxx, ring and ask rather than assuming. ## Wallisdown motorists: the short version Read the cap before you tip. Still AdBlue in your diesel tank? Petrol in Diesel can empty it where it stands, anywhere in Dorset: switch it off then phone 0333 366 0103.