--- title: Northend: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/northend-essex-cb11-4/ location: Northend county: Essex latitude: 52.033170 longitude: 0.215860 service: AdBlue in a Diesel Tank updated: 2026-10-19 --- # Northend: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? AdBlue already in your diesel tank? Then set this page down a moment, leave the ignition and engine off, and ring 0333 366 0103. Around Northend, finding it before the engine runs normally means draining and a full flush where it stands. The rest of this page explains why it takes place and how to ensure it doesn't — useful if you're reading ahead of time. ## AdBlue in a diesel vehicle, and its separate tank Many modern diesels on the roads around Northend and Little Chesterford carry two liquids, not one. Diesel goes to the motor. Kept in a tank of its own, AdBlue is sprayed into the exhaust gas to clean it. Different tanks, separate fillers. Under one flap, next to each other: that's the arrangement on a lot of cars. On others, AdBlue's filler sits beneath the bonnet or in the boot instead. At the petrol pump, your diesel side gets filled all the time. Seldom filled, AdBlue usually comes out of a bottle, tipped by someone who has to stop and think which filler to use. That gap is where the slip lives. ## How AdBlue in your diesel tank occurs around Northend It's seldom carelessness. Three things tend to line up. On a drive off North End before work, or in the car park at Queen's Head on the way home: that is where the hurried top-up happens. What is the reason for the rush? As AdBlue gets low the vehicle warns you, and once it's empty, limp mode follows. Then the car is unfamiliar. A hire car, a new car or a company car puts the fillers where your last one didn't, and your hand gets to for the cap it would have used on the old one. A spouted bottle meets no obstacle at a diesel filler no more than at an AdBlue one. So the tip, once begun, keeps on. It's seconds, be it in Littlebury or bang in the centre of Northend. ## How to tell the AdBlue filler from the diesel one Be it a Northend forecourt or a driveway out in Catmere End, spend a few seconds over these before anything goes in. - Colour and lettering: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap normally doesn't. Trust the cap, not where it sits. - On many vehicles, the size tells: AdBlue has the smaller filler neck. - The flap. Look inside the fuel flap for a label. Plenty of vehicles say there which fuel goes where. - In your boot or under the bonnet: that's where the filler sits if it is not by the diesel cap, and the handbook says which. - The person who drove the car last. On a hire or company car collected from somewhere like the car park outside Audley End, 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 Essex that is. - Not in a rush on the side of Walden Road, not on a slope, not with the engine running: park then switch off properly. - Locate the AdBlue filler, read the cap, and say the word "AdBlue" out loud while you unscrew it. It sounds silly. It does the trick. - The two behind a single flap? Then confirm the cap on your diesel filler is still shut before 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, close the cap and look a second time that your diesel cap never opened off. Stop there if you find, at step two or three, that you've already poured into the diesel side. Do not go on to stage five. ## Put AdBlue in the diesel tank in Northend already? Do not start the engine: that's where the short order of things begins. Don't switch your ignition on; on many diesels that alone runs the fuel pump. Filling up with diesel will not weaken it: rather than mixing, AdBlue drops to the base of your tank, right where fuel is drawn from. At a forecourt — Tesco, Gulf or another — the attendants will normally help roll the car clear, if you ask. If you're on your own drive in Northend, leave the car where it sits. Already started? Pull over when it's sensible, then switch off. The next exit is where to come off when you're on the M11, under 3 miles from Northend. Tell us about how far it went: a run towards Cambridge, under 15 miles away, is a bigger job than a short hop across Northend. ## Northend: what happens when we arrive Our van reaches the vehicle anywhere it has come to rest — your own drive, near Littlebury Village Hall, or outside St Mary's Church of England Voluntary Aided Primary School. Both the work and our quote depend on three answers — which fluid, what quantity, and if it has run — so our technicians ask. During the phone call itself, you are told our quote — before dispatch. Draining your tank comes next, then a thorough flush of the fuel system. With AdBlue that matters 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 last: before that, clean diesel goes in, and your filter is flushed or changed if necessary. Before we go, our technicians start it and check that it's running properly. Using pumps fine on a working forecourt and quiet enough to use outside a house at night, most jobs in which the engine hasn't run need about half an hour after we are there. Nothing in advance; you settle up on the day. Afterwards, the VAT invoice and the report from the engineer go to you for the insurer. Many insurance policies include misfuelling cover, so it is worth checking yours while we're on the way. ## About Northend and where it is Northend is a small hamlet situated on the riverside in Essex, with an elevation of around 45 metres. Northend lies near the cities of Cambridge and Saffron Walden, and is also close to the villages of Littlebury and Audley End. Northend has a population of approximately 605 people and is characterised by predominantly detached housing. Northend is located 39.2 miles from London, making it a rural retreat within commuting distance of the capital. ## AdBlue drains around Northend, and Essex beyond Being a rural hamlet, Northend has the same vans as nearby areas — Audley End, Saffron Walden — all the way across CB postcodes and the wider area beyond. Quickest of all: quote a CB11 4 postcode to our van. Your car stays where it is. A drive, a lay-by on the way to Littlebury Recreation Ground, a side street close to Holy Trinity, Littlebury: our engineers drain the vehicle where it is. Tricky to pin down, like the back of Springwood column? By a border? Checking is better than guessing, so ring. ## Northend drivers: the short version Pour nothing till you have read the cap. AdBlue in your diesel tank after all? Leave the car off then call 0333 366 0103; Petrol in Diesel empties it where it stands, across Essex.