--- title: Littledown: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/littledown-dorset/ location: Littledown county: Dorset latitude: 50.738410 longitude: -1.832090 service: AdBlue in a Diesel Tank updated: 2026-10-17 --- # Littledown: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? If AdBlue is already in your diesel tank, stop reading for a moment: leave your engine and the ignition off then ring 0333 366 0103. In Littledown, catching it before the motor turns normally leaves a drain and a thorough flush on the spot. The rest of this page explains why it takes place and how to make sure it doesn't — handy if you are reading ahead of time. ## Why does AdBlue in a diesel vehicle need its own filler? Diesel goes to the motor — yet many newer diesels driven round Littledown and Townsend carry a second fluid too. The exhaust, not your motor, is where AdBlue goes: dosed into the gas to fresh it, from its own tank. There is a filler on every tank. Some vehicles put the AdBlue filler in the boot or under the bonnet; a lot of others place the two together behind one flap. Filling the diesel side at the petrol pump happens constantly. A driver who has to stop and think where it goes normally tops up the AdBlue side, from a bottle, and much less regularly. The slip lives in that gap. ## AdBlue in your diesel tank around Littledown: how it happens Rarely is it carelessness: usually three things coincide. Haste comes from the warning. The car tells you as AdBlue runs low, and an empty tank puts the vehicle into limp mode — so the top-up gets done quickly, before work on a driveway off Harewood Crescent, or on the way home in the car park at Queens Park Hotel. Next, your hand goes for the cap it would have used on the old motor — because a hire car, a new car or a company car places the fillers where your last one didn't. Third, the spout fits: a diesel filler or AdBlue one, it slides in as readily, and once the pour begins, no part halts it. It's seconds, be it in Holdenhurst or bang in the heart of Littledown. ## Telling the AdBlue filler from your diesel filler A few seconds is all these take — so run through them before you tip anything, on a drive in Boscombe or a forecourt around Littledown. - Blue and marking: an AdBlue cap is commonly blue, or says "AdBlue", where a diesel cap normally doesn't. Go by the cap, not where it sits. - Look at the size: the smaller filler neck is, on plenty of vehicles, the AdBlue one. - Check inside your fuel flap: many cars carry a label there saying which fuel goes where. - The handbook. If the filler isn't by your diesel cap, it's in your boot or under the bonnet, and the handbook says which. - The person who drove the vehicle last. On a hire or company car collected from somewhere like the car park at Pokesdown, ask before you leave, not when the light comes on. ## How to top up without AdBlue in the diesel tank When the light goes on, wherever around Dorset, use this routine. - Stop somewhere level, motor off, with time to spare — never rushing on the side of Harewood Avenue. - Silly as it sounds, speaking "AdBlue" out loud as you unscrew the cap works — after you have located your filler and read the cap. - Leave your diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Using the bottle's own spout, pour slowly — and stop when it is full or the bottle is empty. - Shut the cap, and look again — making sure the diesel filler remained closed throughout. Only then, start the vehicle. Find at stage two or three that it's already gone into the diesel side? So stop right there. Leave out stage five entirely. ## AdBlue in the diesel tank already, around Littledown? Brief order, then. Top of it: the motor stays off. Leave your ignition off as well, because on many diesels it alone runs the pump. Do not top up with diesel to dilute it: AdBlue doesn't mix with diesel, it sinks to the bottom of the tank, where your fuel is sucked from. On a forecourt — Esso, Tesco or any other — the attendants will usually help roll the car clear, if you ask. Your own drive in Littledown is where it stays. Already run? Stop once it's sensible, then switch off. Leave the M27 — under 25 miles out of Littledown — at the next junction. Mileage matters — a short hop across Littledown makes a smaller job than heading under 25 miles to Southampton — so say about how far it went. ## What occurs when our engineers arrive around Littledown Outside Avonwood Primary School, near East Cemetery Chapel or on your own driveway: wherever your car has stopped, our engineers come to it. Which liquid was put in, the amount, and if it ran: our technicians ask because those answers decide the work and price. You hear that quote on the phone, before anyone sets off. Then that tank is cleared and the fuel system flushed thoroughly. More than with petrol, it matters here: crystals form, certain metals are attacked, and none of it washes out on its own, no matter how long it is left. The filter flushed or, if it must be, replaced; fresh diesel in; and then a test of the car. Your engine is started next and checked to make sure it runs properly, all before our engineers head off. If the engine hasn't run, most jobs take about half an hour once we are there, using pumps that are fine on a working forecourt and quiet enough to use outside a house after dark. No money in advance; you settle up that day. At the end, a VAT invoice and the report from the engineer go to you for your insurer. Misfuelling cover is part of many insurance policies — and so use the wait to look at yours. ## About Littledown, briefly Littledown is a coastal suburban area in Dorset, situated near the towns of Holdenhurst and Pokesdown, with Littledown being a predominantly residential community. Littledown has a mix of housing types, but detached homes are the most common, and Littledown is located at a relatively low elevation of 27 metres above sea level. Littledown is close to several nearby hills, including Haddon Hill, and Littledown is within easy reach of the city of Southampton, which is approximately 22 miles away. ## AdBlue drains in Littledown and across Dorset Pokesdown and Haddon Hill are among the towns near Littledown, a residential suburb, that the same teams cover, over BH postcodes. Quickest of all: quote a BH7 7 postcode for the van. The car doesn't need to shift. A drive, a lay-by on the way to Kings Park, a side street near Kings Park Leisure and Learning Centre: we drain it where it sits. Tricky to explain, like the back of MCC Bournemouth? By a county line? Asking beats assuming, and so ring. ## For Littledown motorists, the short version Read the cap before you tip. Petrol in Diesel drains it on the spot, anywhere across Dorset, if AdBlue has gone in the diesel tank all the same — so leave the vehicle off then ring 0333 366 0103.