--- title: AdBlue in a Diesel Tank Great Shelford? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/great-shelford-cambridgeshire/ location: Great Shelford county: Cambridgeshire latitude: 52.150350 longitude: 0.135760 service: AdBlue in a Diesel Tank updated: 2026-10-22 --- # Great Shelford: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? AdBlue already in the diesel tank? In that case set this page aside for now, leave the ignition and motor off, and call 0333 366 0103. A drain plus a thorough flush, done just where the vehicle stands around Great Shelford, is normally what it needs if found before the engine runs. The rest of this page covers why it happens and how to make sure it doesn't — handy if you are reading ahead of time. ## Two fillers, two tanks: AdBlue in a diesel vehicle Not one fluid but two: that's how many newer diesels near Great Shelford and Hauxton carry, with diesel for the engine. The exhaust, not the motor, is where AdBlue goes: dosed into the fumes to clean them, from its own tank. Each tank comes with one filler of its own. Plenty of motors have a single flap for both, whereas others put the AdBlue filler to the boot or under the bonnet. At the petrol pump, your diesel side gets filled constantly. Far less commonly, the AdBlue side gets filled — normally from a bottle, by someone thinking about where it goes. It's in that gap that the error happens. ## How does AdBlue in your diesel tank take place in Great Shelford? Carelessness seldom causes it. What does is three things lining up at once. Hurry follows from the warning. The vehicle warns you as AdBlue runs low, and a dry tank puts the vehicle into limp mode — so the top-up happens quickly, before work on a drive off Tunwells Lane, or on the way home in the car park outside The Plough. Unfamiliar cars are next, as well. Rentals, new motors and company motors put their fillers differently, and habit reaches for the cap it used on the old one. Lastly, the spout fits: diesel filler or AdBlue one, it slides in as readily, and once the tip begins, no part halts it. Freestones Corner or the middle of Great Shelford: it takes the same few seconds in both. ## How to tell the AdBlue filler from the diesel one Before you tip anything, whether on a driveway in Trumpington or a forecourt around Great Shelford, check these. They take a few seconds. - The cap. The AdBlue cap is commonly blue, or marked "AdBlue". Your diesel cap usually is not. Read it instead of going by where it sits. - On many cars, the size tells: AdBlue has the smaller filler neck. - Look inside the fuel flap: plenty of vehicles have a label there showing which fuel goes where. - The handbook. If your filler is not by the diesel cap, it's in the boot or under the bonnet, and the handbook says which. - Whoever had it before will know. Check when you pick up a rental or company car — from Shelford's car park, say — not once the warning appears. ## Topping up AdBlue without it reaching your diesel tank Anywhere around Cambridgeshire the light comes on, here is a routine for the day. - Park and switch off. Not on a slope, not with your motor running, and not in a rush on the side of High Green. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it does the trick. - Leave the diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Finish once the tank is topped up or the bottle is empty; before that, tip gently through the own spout. - Close the cap and check again. Make sure your diesel cap was never opened. Only then start your car. Discover during the second or third step that the bottle went into the diesel tank? That is where you stop. Never carry on to stage five. ## AdBlue in the diesel tank already, around Great Shelford? Short order, then. First: the engine stays off. Don't switch your ignition on; on many diesels that alone runs the fuel pump. AdBlue does not mix with diesel — it sinks to the bottom of the tank, where the fuel is pulled from — so don't top up with diesel to thin it. The staff at Esso, Shell or another forecourt will normally lend a hand pushing the car clear when you ask. If you're on your own driveway around Great Shelford, leave it where it stands. Stop as soon as it is safe then switch off, if your engine has already run. On the M11, under 3 miles from Great Shelford, that means the next exit. Distance counts — a quick hop across Great Shelford makes a smaller job than driving under 5 miles to Cambridge — so say roughly how far it went. ## Great Shelford: what occurs when we turn up Our van comes to your car anywhere it has come to rest — your own driveway, beside Shelford Free Baptist Church, or outside Great and Little Shelford CofE (Aided) Primary School. We ask what got in, roughly how much, and whether it has run, because those replies settle the work and our price. You hear that price on the phone, before anyone heads out. The fuel system is then rinsed thoroughly, once the tank is emptied. Unlike petrol, AdBlue leaves crystals and eats at certain fuel-system metals, and neither clears away unaided. That is why it matters more. The filter is flushed, or replaced where it needs to be; fresh diesel goes in; and the vehicle is tested. The motor is fired up next and checked to be sure it runs properly, all before our engineers go. Most jobs are done in about half an hour once our technicians get there, as long as your motor has not run — and the pumps our technicians use are safe on a busy forecourt yet quiet after dark outside a house. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Before we get there, have a look at your insurance documents; plenty carry cover for misfuelling. ## About Great Shelford Great Shelford is a village situated on the River Cam in Cambridgeshire, with a low elevation of around 19 metres. Great Shelford lies close to the city of Cambridge, approximately 3.8 miles to the south, and is part of the wider Cambridge urban area. Great Shelford has a mix of housing types, but semi-detached homes are particularly prevalent in the village. Great Shelford is also near to other small settlements, including Freestones Corner, Stapleford, and Little Shelford. ## Great Shelford and Cambridgeshire: AdBlue drains across the area Stapleford and Little Shelford are among the towns near Great Shelford, a village, that the same vans cover, throughout CB postcodes. Quickest of all: quote a CB22 5 postcode for our van. No need to shift the car. Our engineers drain it where it is — a side street near Great Shelford Library, a lay-by on the way to Villedomer Garden, a drive. Guessing won't help at the back of Memorial Hall, close to a boundary, or somewhere hard to pin down; phone and check. ## The short version for Great Shelford people Read the cap before you tip. Even so AdBlue in your diesel tank? Petrol in Diesel can empty it where it is, wherever around Cambridgeshire: keep it off and ring 0333 366 0103.