--- title: Explained: AdBlue in a Diesel Tank Overleigh canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/overleigh-somerset/ location: Overleigh county: Somerset latitude: 51.116970 longitude: -2.737930 service: AdBlue in a Diesel Tank updated: 2026-10-15 --- # AdBlue in a Diesel Tank in Overleigh: How It Occurs and How to Stop It Keep your motor and ignition off then phone 0333 366 0103 now — the rest can wait if AdBlue is already in your diesel tank. Around Overleigh, finding it before the motor runs usually leaves draining and a full flush where it stands. Nothing happened yet? Below, the rest of the page covers the reasons it occurs and the ways to avoid it for good. ## Two fillers, two tanks: AdBlue in a diesel car Diesel goes to your motor — but many modern diesels seen about Overleigh and Lower Leigh hold another fluid too. The exhaust, not your motor, is where AdBlue goes: dosed into the fumes to clean them, from its own tank. Every tank has a filler of its own. Under one flap, side by side: that's the arrangement on many vehicles. Elsewhere, AdBlue's filler is beneath the bonnet or in the boot instead. Filling your diesel side at the petrol pump goes on constantly. The AdBlue side is fuelled far less often, normally from a bottle, and usually by somebody who has to stop and think where it goes. It is in that gap that the mistake happens. ## How AdBlue in the diesel tank happens in Overleigh Carelessness rarely causes it. Instead is three things lining up at once. The warning comes first. As AdBlue runs low your car tells you, and if it runs out completely, the vehicle goes into limp mode. So the top-up is done in a hurry: on a driveway off Overleigh before work, or in the car park outside The King Alfred on the way home. Then the vehicle is new. A hire car, a new car or a company car puts the fillers where your last one did not, and your hand reaches for the cap it would have used on the old one. Lastly, the bottle goes in: a diesel filler or AdBlue filler, it slides in just as readily, and after the tip starts, no part halts it. The same few seconds settle it, in the middle of Overleigh or out in Middle Leigh. ## How to tell the AdBlue filler from the diesel one Whether a Overleigh forecourt or a drive out in Marshalls Elm, spend a few seconds on these before any goes in. - Position misleads; the cap does not. AdBlue ones are often blue or bear the word "AdBlue" — diesel caps normally do not. - On plenty of motors, size tells: AdBlue has the smaller filler neck. - The flap. Look inside your fuel flap for a label. Many vehicles say there which fuel goes where. - The handbook. If the filler isn't by your diesel cap, it's in your boot or under the bonnet, 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 Castle Cary, ask before you leave, not when the light comes on. ## How to top up without AdBlue in the diesel tank A routine for the day the light comes on, wherever in Somerset that is. - Not in a rush on the side of Stallgrove Lane, not on a slope, not with the motor running: park then switch off first. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it works. - The two behind a single flap? So confirm the cap on the diesel filler stays closed before lifting the bottle. - Slowly does it, through the bottle's own spout, till it is full or the bottle runs out. - Only after that, start the vehicle: close the cap, check a second time, and make sure the diesel cap was never opened. Stop there if you find, at stage two or three, that you've already poured into your diesel side. Step five is off limits. ## Put AdBlue in your diesel tank around Overleigh already? Brief order, then. Top of it: the motor stays unstarted. The fuel pump runs on many diesels as soon as your ignition is switched on — so leave it off. Don't top up with diesel to thin it: AdBlue doesn't mix with diesel, it sinks to the bottom of your tank, where the fuel is pulled from. The attendants at Sainsbury's, Shell or any forecourt will usually lend a hand to push the car away when asked. Leave it where it is if you're on your own driveway around Overleigh. If your engine has already run, stop as soon as it is safe then switch off. On the M5, under 15 miles from Overleigh, that means the next junction. Tell us about how far it went: a run towards Wells, under 10 miles away, is a bigger job than a short hop across Overleigh. ## Our arrival in Overleigh, and what happens next Outside Hindhayes Infant School, near The Salvation Army - Street or on your own driveway: wherever the vehicle has stopped, we come to it. Both the work and our quote depend on three replies — what liquid, what quantity, and if it's run — so our engineers ask. Nobody sets off before you have had our price by phone. The fuel system is then rinsed thoroughly, once your tank is drained. Not like petrol, AdBlue forms crystals and attacks certain fuel-system metals, and none of that washes out unaided. Hence it matters more. Testing comes at the end: before that, fresh diesel goes in, and the fuel filter is flushed or changed if necessary. After that we start the engine and confirm it runs properly before we leave. If the engine hasn't run, the majority of jobs take about half an hour once we are there, using pumps that are safe on a working forecourt and quiet enough to use outside a house after dark. No money upfront; you settle up on the day. Afterwards, the VAT invoice and the report from the engineer are handed to you for the insurer. While we travel, have a look at your policy; plenty include cover for misfuelling. ## About Overleigh and where it is Overleigh is a suburban area in Somerset, situated inland at an elevation of 36 metres, approximately 7.5 miles from the city of Wells. Overleigh is characterized by its semi-detached housing and is located near other residential areas such as Middle Leigh and Portway. Overleigh sits within the wider region of the South West, around 115.9 miles west of London. ## Overleigh and Somerset: AdBlue drains across the area As a residential suburb, Overleigh has the same vans as nearby places — Portway, Stone Hill — all the way through BA postcodes and the wider area beyond. The van gets to you fastest with a postcode starting BA16 0. Your car stays where it is. Anywhere it sits — beside Mission Church, in a lay-by en route to Wraxhill Park, at home — that is where it is drained. If you are close to a boundary, or somewhere hard to explain like the back of The Bayliss Centre, ring and ask instead of assuming. ## The short version for Overleigh people Always, the cap; then, the tip. Petrol in Diesel empties it where it stands, anywhere across Somerset, if AdBlue has gone in the diesel tank anyway — so leave it off and ring 0333 366 0103.