--- title: Explained: AdBlue in a Diesel Tank Assington canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/assington-suffolk/ location: Assington county: Suffolk latitude: 52.007640 longitude: 0.816560 service: AdBlue in a Diesel Tank updated: 2026-10-16 --- # AdBlue in a Diesel Tank in Assington: How It Happens and How to Stop It Keep the motor and ignition off then phone 0333 366 0103 first — the rest can wait when AdBlue is already in your diesel tank. In Assington, finding it before your motor runs normally means a drain and a thorough flush where it stands. Nothing happened yet? Further down, the page covers the why it happens and the how to avoid it altogether. ## Two fillers, two tanks: AdBlue in a diesel vehicle Not one fluid but two: that is how plenty of newer diesels around Assington and Sackers Green carry, with diesel for your motor. Kept in a tank of its own, AdBlue is fed into the exhaust stream and cleans it. Separate tanks, different fillers. Under one flap, side by side: that's the arrangement on many motors. On others, AdBlue's filler is beneath the bonnet or in your boot instead. The diesel side is filled at the pump all the time. The AdBlue side is filled far less regularly, usually from a bottle, and usually by someone who has to stop and think where it goes. It is in that gap that the slip happens. ## AdBlue in your diesel tank in Assington: how it occurs Carelessness seldom causes it. What does is three things coming up together. To start with, the warning. Low AdBlue brings a warning from the car, and running dry means limp mode — hence a rushed top-up, perhaps before work off The Street, perhaps at Shoulder of Mutton on the way home that evening. Unfamiliar motors come second, too. Hire cars, new motors and company cars put their fillers in new places, and habit reaches for the cap it used on the old one. A spouted bottle meets no resistance at a diesel filler no more than at an AdBlue one. And so the tip, once started, carries on. The same few seconds decide it, in the middle of Assington or out in Leavenheath. ## How to tell the AdBlue filler from the diesel one Be it a Assington forecourt or a driveway out in Honey Tye, spend a few seconds on 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 its position. - Look at the size: the smaller filler neck is, on plenty of vehicles, the AdBlue one. - The flap. Look inside your fuel flap for a label. Plenty of motors say there which fuel goes where. - In the boot or under the bonnet: that is where the filler sits if it's not by your diesel cap, and the handbook says which. - Ask the person who drove it last — before you leave, not when the light comes on — if you collect a hire or company car from somewhere like the car park at Bures. ## Keeping AdBlue out of the diesel tank when you top up A routine for the day the light comes on, wherever in Suffolk that is. - Park and switch off. Not on a slope, not with the engine running, and not in a rush on the side of Meadow Way. - Say "AdBlue" out loud as you unscrew the cap, once finding the AdBlue filler and read it. Daft, perhaps, yet it does the trick. - The two under one flap? Then make sure the cap on the diesel side stays shut before lifting the bottle. - Pour slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty. - Close the cap, then check again — confirm the diesel cap stayed closed the whole time. After that, start your car. Spot at step two or three that it's already gone into the diesel side? Then stop just there. Skip step five altogether. ## Put AdBlue in the diesel tank around Assington already? Then the order of things is short. Don't start your motor. The fuel pump starts on plenty of diesels as soon as the ignition goes on — so leave it off. AdBlue does not mix with diesel — it sinks to the bottom of your tank, where your fuel is drawn from — so don't top up with diesel to thin it. The staff at Esso, Sainsbury's or another forecourt will normally lend a hand pushing the car away when you ask. If you are on your own driveway in Assington, leave the car where it sits. Where your motor has run already, pull over somewhere safe then switch the car off. On the M11, under 50 miles from Assington, that means the next exit. A short hop across Assington is a smaller job than a run towards Colchester, under 10 miles away, and so tell us about how far it went. ## Assington: what takes place when we get there Our engineers come to the car wherever it has stopped, whether that is outside Boxford Church of England Voluntary Controlled Primary School, close to Assington Village Hall or on your own drive. The replies settle this work and our price, so our engineers ask what was put in, about how much, and if it's run. No one heads out until you have heard our price by phone. Then that tank is cleared and your system purged thoroughly. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own. After the filter is cleaned — or renewed, if required — fresh diesel is added, and finally your vehicle gets tested. We don't go until it has been started and is running properly. If the motor hasn't run, the majority of jobs take about half an hour once we are there, using pumps that are safe on a busy forecourt and quiet enough to use outside a house at night. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Wrong-fuel cover is part of plenty of insurance policies — and so use the wait to look at yours. ## About Assington and where it is Assington is a small village in Suffolk, situated inland at an elevation of around 60 metres, and is located approximately 53 miles from London. Assington lies near the larger town of Colchester, which is about 9 miles away, and is also close to other nearby places such as Leavenheath and Hagmore Green. Assington has a population of around 514 people and is characterised by predominantly detached housing. Assington is surrounded by the rolling countryside of the Suffolk landscape. ## AdBlue drains around Assington, and Suffolk beyond Throughout CO postcodes, the teams covering Assington — a rural village — work the surrounding spots too, Dorking Tye and Hagmore Green included. Fastest of all: give a CO10 5 postcode for the van. Moving the car is not necessary. A drive, a lay-by on the way to Ostrich Grove, a side street close to St Edmund: we drain it where it is. If you are close to a border, or somewhere hard to explain like the back of Leavenheath Village Sign, ring and ask rather than assuming. ## For Assington people, the short version Always, the cap; after that, the tip. If AdBlue has gone in your diesel tank all the same, leave the vehicle off and ring 0333 366 0103. Petrol in Diesel drains it where it sits, anywhere around Suffolk.