--- title: Little Downham: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/little-downham-cambridgeshire/ location: Little Downham county: Cambridgeshire latitude: 52.431800 longitude: 0.238720 service: AdBlue in a Diesel Tank updated: 2026-10-04 --- # Avoiding AdBlue in a Diesel Tank in Little Downham: Why It Happens Stop here a minute if the diesel tank already has AdBlue in it: ignition off, engine off, and call 0333 366 0103. Normally, when your engine has not turned, it's drained and fully cleaned where the vehicle is around Little Downham. If you are reading before it has happened, the remainder of this page is about why it happens and how to make sure it doesn't. ## Why does AdBlue in a diesel vehicle need its own filler? Many newer diesels around Chettisham, like those in Little Downham, run on two liquids; the motor gets just your diesel. AdBlue's own tank holds it, and from there it is sent to the exhaust, where a spray treats the gas. Each tank comes with a filler of its own. Some motors keep the AdBlue filler in your boot or under the bonnet; plenty of others place the two side by side under one flap. The diesel side is fuelled at the pump all the time. Much less regularly, the AdBlue side is topped up — normally from a bottle, by a person thinking about where it goes. The mistake grows in the gap between the two. ## How AdBlue in your diesel tank occurs in Little Downham Rarely is it carelessness: usually three things line up. Haste follows from the warning. The vehicle tells you as AdBlue runs low, and an empty tank puts the vehicle into limp mode — so the top-up happens in a rush, before work on a drive off Main Street, or heading home in the car park at The Plough. Next, your hand reaches for the cap it knew on the old vehicle — since a hire car, a new vehicle or a company car places the fillers where your last one did not. A spout-topped bottle finds no obstacle at a diesel filler no more than at an AdBlue one. And so the pour, after begun, carries on. Whether it takes place in Black Bank or the middle of Little Downham, it is the same few seconds. ## The AdBlue filler and your diesel filler: telling them apart Check these first, at a forecourt around Little Downham or a driveway out in Second Drove. A few seconds, that's all. - The cap. The AdBlue cap is often blue, or marked "AdBlue". The diesel cap normally isn't. Read it rather than going by position. - Look at the size: the smaller neck is, on many vehicles, the AdBlue one. - Check inside the fuel flap: plenty of vehicles have a label there saying which fuel goes where. - The handbook. If the filler is not by your diesel cap, it is in the boot or under the bonnet, and the handbook says which. - Check with the person who drove it last — before you leave, not when the light comes on — when you collect a hire or company car from somewhere like the car park outside Ely. ## Topping up AdBlue without it reaching the diesel tank The day the light goes on, wherever in Cambridgeshire, use this routine. - Not in a rush on the side of Chapel Lane, not on a slope, not with your engine running: park and switch off properly. - Find the AdBlue filler, read the cap, and speak the word "AdBlue" aloud while unscrewing it. It sounds silly. It works. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave it on. - Gently is best, through the bottle's own spout, until it is full or the bottle is empty. - Close the cap and check a second time. Make sure the diesel cap was never opened. Only then start your car. Find at the second or third step that AdBlue went into the diesel tank? That's where you stop. Skip step five altogether. ## Already put AdBlue in the diesel tank in Little Downham? Brief list, then. Top of it: your engine stays unstarted. The fuel pump runs on plenty of diesels the moment your ignition is switched on — and so leave it off. AdBlue does not mix with diesel — it sinks to the bottom of the tank, where your fuel is sucked from — so don't top up with diesel to dilute it. If you are at a forecourt, whether it is the ALS Autos or the another forecourt nearby, ask the staff to help roll your car away from the petrol pump. If you are on your own driveway in Little Downham, leave the vehicle where it is. Stop as soon as it is safe then switch off, if your motor has already run. On the M11, under 25 miles from Little Downham, that means the next exit. A short hop across Little Downham is a smaller job than a run towards Ely, under 3 miles away, and so tell us about how far it went. ## When our engineers get there in Little Downham, what happens? Outside Downham Feoffees Primary Academy, near Little Downham Baptist Chapel or on your own drive: wherever the vehicle has stopped, our engineers come to it. The replies settle this work and the quote, and so we ask what went in, roughly how much, and whether it has run. You get that quote on the phone, before anybody sets off. Next: a drain, then a full flush of the whole system. Much more than with petrol, it matters with AdBlue: the crystals form, certain metals corrode, and nothing clears away on its own, no matter how long it is left. The filter flushed or, where it must be, swapped; clean diesel in; then a test of the car. Before we leave, our technicians fire it up and check that it's running smoothly. 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. Your insurer will ask for an engineer's report and your VAT invoice, and both are yours at the end. Payment comes on the day, with no deposit. Plenty of insurance policies include misfuelling cover, and so it is worth checking yours while we are on the way. ## About Little Downham Little Downham is a village in Cambridgeshire, situated near the city of Ely and surrounded by nearby places such as Black Bank and Downham Hythe. Little Downham sits at a low elevation of around 22 metres, in a flat and generally low-lying inland area. Little Downham has a population of approximately 1234 people, living in predominantly detached housing. ## AdBlue drains round Little Downham, and Cambridgeshire beyond Dunkirk and Downham Hythe are among the towns around Little Downham, a rural village, that the same teams cover, throughout CB postcodes. A postcode starting CB6 2 gets our van to you fastest. The vehicle remains put. A driveway, a lay-by on the way to Pingle Wood, a side street near Little Downham Village Hall: our technicians drain the vehicle where it stands. Ring and ask instead of assuming if you're close to a boundary, or somewhere hard to describe, like the back of St Leonard (Little Downham Parish Church). ## The short version for Little Downham drivers Tip nothing until you have read the cap. Even so AdBlue in your diesel tank? Petrol in Diesel will drain it where it stands, anywhere in Cambridgeshire: switch it off and phone 0333 366 0103.