--- title: Christchurch: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/christchurch-dorset/ location: Christchurch county: Dorset latitude: 50.738370 longitude: -1.781810 service: AdBlue in a Diesel Tank updated: 2026-10-21 --- # Preventing AdBlue in a Diesel Tank in Christchurch: Why It Happens AdBlue already in your diesel tank? In that case put this page aside for now, keep the ignition and engine off, then ring 0333 366 0103. A drain plus a full flush, done just where the vehicle sits around Christchurch, is usually what it takes if caught before your engine runs. Reading in advance? In that case the rest covers how it happens and how to prevent it ever happening. ## Why does AdBlue in a diesel motor need its own filler? Plenty of newer diesels on the roads around Christchurch and Wick carry two liquids, not one. Diesel goes to the engine. Stored in a tank of its own, AdBlue is sprayed into the exhaust stream to clean it. Each tank has its own filler. Under one flap, side by side: that's the layout on many vehicles. On others, AdBlue's filler is beneath the bonnet or in your boot instead. Diesel goes in at every filling station call-out, again and again. Far less commonly, the AdBlue side gets topped up — mostly from a bottle, by a person working out where it goes. That gap is where the error lives. ## How AdBlue in the diesel tank happens around Christchurch Rarely is it carelessness: usually three things coincide. The warning comes first. As AdBlue runs low your car tells you, and if it runs out completely, your vehicle drops into limp mode. So the top-up is done in a hurry: on a driveway off Fairfield before work, or in the car park at The Railway on the way home. Then, the hand goes for the cap it would have used on the old car — since a rental car, a new motor or a company car puts the fillers where your last one didn't. No part stops the tip after it has started, because a bottle with a spout goes into a diesel filler as readily as an AdBlue one. The bottle fits. Whether it takes place in Fairmile or the middle of Christchurch, it is the same few seconds. ## How to tell the AdBlue filler from the diesel one A couple of seconds is all the checks take — so run through them before you pour anything, on a driveway in Burton or a forecourt around Christchurch. - Read the cap instead of going by position: AdBlue caps are regularly blue or marked "AdBlue", and diesel caps normally are not. - The size. On plenty of vehicles the AdBlue filler neck is the smaller of the two. - Look inside your fuel flap: plenty of vehicles have a label there saying which fuel goes where. - The handbook shows which it lives when the filler is not next to your diesel cap: your boot, or under the bonnet. - Picking up a hire or company car, say at the car park at the nearest station? Check with the person who drove it last before leaving, not when the light comes on. ## Topping up AdBlue without it reaching the diesel tank A routine for the day the light comes on, wherever in Dorset that is. - Not in a rush on the side of Twynham Avenue, not on a slope, not with the engine running: park then switch off first. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds silly and it works. - Leave the diesel cap on. If both sit under one flap, check the diesel cap is still closed before you lift the bottle. - Gently does it, through the bottle's own spout, until it's full or the bottle runs out. - Close the cap, then check once more — making sure your diesel filler stayed shut the whole time. Only then, start the car. Discover during the second or third stage that AdBlue went into the wrong tank? That is where you stop. Skip step five entirely. ## Put AdBlue in the diesel tank around Christchurch already? Do not start your motor: that's where the short order of things begins. On many diesels your ignition alone runs the fuel pump, and so don't switch it on. Topping up with diesel won't dilute it: rather than mixing, AdBlue sinks to the bottom of your tank, just where fuel is taken from. If you're on a forecourt, whether it is the Shell or the Murco, ask the staff to help push the car away from the pump. Leave it where it is if you are on your own driveway in Christchurch. Where your motor has run already, stop safely and turn the car off. On the M27, under 15 miles from Christchurch, that means the next junction. Distance counts — a quick hop across Christchurch is a smaller job than heading under 25 miles to Southampton — so tell us about how far it went. ## Our arrival around Christchurch, and what happens next Our technicians come to the vehicle wherever it has stopped, whether that is outside Christchurch Infant School, near The Salvation Army - Christchurch or on your own drive. Both the work and our quote rest on three answers — which liquid, which quantity, and if it's run — so we ask. Nobody sets off before you've heard the price by phone. Your system is then purged thoroughly, after the tank is cleared. Unlike petrol, AdBlue leaves crystals and attacks some fuel-system metals, and none of it washes out unaided. Hence it counts more. After the fuel filter is cleaned — or renewed, where needed — fresh diesel goes in, and then your vehicle gets tested. The motor is fired up next and tested to be sure it runs smoothly, all before our engineers go. Unrun cars usually mean a half-hour visit after the moment we arrive. The equipment is fine on a busy filling station, and hushed enough for a residential street late at night. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Misfuelling cover is included in many insurance policies — and so make use of the wait to look at yours. ## About Christchurch, for a moment Christchurch is a coastal town in Dorset, situated on the south coast of England, with a low elevation of around 5 metres above sea level. Christchurch lies near the cities of Southampton and Bournemouth, and is close to smaller communities such as Fairmile, Tuckton, and Purewell. Christchurch has a population of approximately 18,569 people, and is characterised by predominantly detached housing. Christchurch is also within commuting distance of larger cities, being around 89 miles from London. ## AdBlue drains around Christchurch, and Dorset beyond Christchurch is a coastal town, and our teams that cover it also work the places around it, Tuckton and Purewell among them, across the BH postcode area. Quickest of all: give a BH23 1 postcode to our van. The car doesn't need to move. Draining takes place on the spot, be it a driveway, a street near Christchurch Baptist Church, or a lay-by on the way to New Zealand Gardens. Guessing won't help behind Druitt Hall, close to a border, or anywhere hard to describe; phone and ask. ## The short version for Christchurch motorists Read the cap before you pour. If AdBlue has gone in the diesel tank all the same, leave the vehicle off and phone 0333 366 0103. Petrol in Diesel clears it where it stands, anywhere across Dorset.