--- title: AdBlue in a Diesel Tank Sling? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/sling-gloucestershire/ location: Sling county: Gloucestershire latitude: 51.768200 longitude: -2.605090 service: AdBlue in a Diesel Tank updated: 2026-10-13 --- # Why It Happens and How to Avoid It: AdBlue in a Diesel Tank in Sling AdBlue already in the diesel tank? In that case put this page down a moment, leave your ignition and motor off, then phone 0333 366 0103. Normally, if the engine hasn't turned, it is emptied and fully flushed where the vehicle sits in Sling. If you are reading before it has happened, the remainder of this page is about why it happens and how to make sure it does not. ## AdBlue in a diesel vehicle, and its separate tank Not one liquid but two: that's what plenty of newer diesels near Sling and Clearwell carry, with diesel for the engine. Kept in a tank of its own, AdBlue is sprayed into your exhaust gas to clean it. Each tank has its own filler. Other motors put the AdBlue filler in the boot or under the bonnet; a lot of others have both side by side behind one flap. At the pump, your diesel side gets filled all the time. Much less commonly, the AdBlue side is topped up — mostly from a bottle, by someone working out where it goes. The mistake grows in the gap between the two. ## Sling: how AdBlue in the diesel tank occurs Three things tend to line up, and carelessness is rarely one of them. On a drive off Marsh Way before work, or in the car park at Club House on the way home: that's where the rushed top-up happens. What is the reason for the rush? As AdBlue runs low the car tells you, and if it's gone, limp mode follows. Then, the hand reaches for the cap it knew on the old car — because a hire car, a new car or a company car puts the fillers somewhere your last one did not. Third, the bottle goes in: diesel filler or AdBlue filler, it slides in as readily, and once the pour starts, no part halts it. The same few seconds settle it, in the middle of Sling or out in Marsh Lane. ## Telling the AdBlue filler from the diesel filler Whether a Sling forecourt or a drive out in Trow Green, spend a couple of seconds on these before any goes in. - The cap. The AdBlue cap is commonly blue, or marked "AdBlue". Your diesel cap usually isn't. Read it rather than going by where it sits. - On plenty of vehicles, the size gives it away: AdBlue has the smaller filler neck. - Open the filler flap and look for a label — many motors show what goes in each filler just there. - Can't find it next to the diesel inlet? In that case look below the bonnet or in your boot — the handbook will say which. - Ask the person who drove it last — before you leave, not when the light comes on — if you pick up a hire or company car from somewhere like the car park outside Lydney. ## How to top up without AdBlue in the diesel tank When the light goes on, anywhere across Gloucestershire, follow this routine. - Not in a rush on the side of Parkend Walk, not on a slope, not with the engine running: park and switch off properly. - Find the AdBlue filler, read the cap, and say the name "AdBlue" out loud as unscrewing it. It seems daft. 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. - Tip slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Before starting the car, shut the cap and look again that the diesel cap never opened off. Find during the second or third stage that the bottle went into the diesel tank? That's where you stop. Stage five stays off limits. ## Sling: already put AdBlue in your diesel tank? Then the order of things is short. Don't start the motor. On many diesels the ignition alone runs the fuel pump, so do not switch the car on. AdBlue does not mix with diesel — it sinks to the bottom of the tank, where your fuel is drawn from — so do not top up with diesel to thin it. At a forecourt — Texaco, Central Garage or another — the attendants will normally help push your car away, when you ask. At home around Sling? Then your car stays where it is. If your engine has already run, stop as soon as it is safe and switch off. Leave the M5 — under 15 miles out of Sling — at the first junction. About how far did it go? Crossing Sling is smaller work than a run of under 25 miles towards Gloucester, and so tell us. ## Our arrival around Sling, and what takes place next The van reaches the vehicle anywhere it stopped — your own driveway, near Clearwell Caves, or outside Ellwood Primary School. Those answers determine this work and the price, and so our engineers ask what got in, roughly how much, and if it's run. You get that price by phone, before anybody sets off. Next: a drain, then a thorough flush of the whole system. Much more than with petrol, it counts with AdBlue: crystals form, some metals corrode, and nothing washes out on its own, however long it sits. Filter flushed or, where it must be, replaced; fresh diesel in; and then a check of your vehicle. Then our technicians start it and make sure it runs correctly before we go. With pumps fine on a working forecourt and quiet enough for use outside a house at night, most jobs in which the motor has not run take about half an hour once our engineers arrive. Paying is on the day, not upfront, and you receive the documents an insurer asks for: an engineer's report and a VAT invoice. It's worth looking at your policy while we travel to you: misfuelling cover is included with many policies. ## About Sling, briefly Sling is a small village in Gloucestershire, situated inland at an elevation of around 200 metres, with semi-detached housing being the predominant type of accommodation. Sling lies near several other small settlements, including Marsh Lane, Ellwood, and Clements End, and is approximately 16.7 miles from the city of Gloucester. Sling has a population of around 895 people and is located in the South West region of England, about 107.7 miles from London. ## AdBlue drains around Sling, and Gloucestershire beyond Sling is a rural village, and our teams that cover it also work the towns around it, Ellwood and Clements End among them, across the GL postcode area. Fastest of all: quote a GL16 8 postcode to our van. No need to shift your car. We drain it where it is — a side street close to Dark Hill, a lay-by on the way to Stock Wood, a driveway. Tricky to pin down, like the back of Clearwell Memorial Hall? By a border? Asking beats guessing, and so phone. ## Sling drivers: the short version Read the cap before you tip. If AdBlue has gone in the diesel tank all the same, leave the car off then phone 0333 366 0103. Petrol in Diesel clears it where it sits, anywhere in Gloucestershire.