--- title: Explained: AdBlue in a Diesel Tank Whitnash canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/whitnash-warwickshire/ location: Whitnash county: Warwickshire latitude: 52.268840 longitude: -1.528530 service: AdBlue in a Diesel Tank updated: 2026-10-10 --- # Preventing AdBlue in a Diesel Tank in Whitnash: Why It Happens If AdBlue is already in your diesel tank, stop reading for a moment: leave the engine and the ignition off then phone 0333 366 0103. A drain plus a thorough flush, done just where the car sits in Whitnash, is usually what it needs when caught before your motor runs. Not happened yet? Further down, the page covers the reasons it happens and the ways to avoid it altogether. ## AdBlue in a diesel car: two tanks, two fillers Not one liquid but two: that is how plenty of newer diesels near Whitnash and Heathcote run, with diesel feeding your motor. AdBlue's own tank keeps it, and from there it is sent to the exhaust, where a spray treats the gas. Separate tanks, separate fillers. Under one flap, next to each other: that's the layout on many cars. On others, AdBlue's filler is beneath the bonnet or in the boot instead. Topping up your diesel side at the petrol pump goes on all the time. Much less frequently, the AdBlue side is filled — normally from a bottle, by a person thinking about where it goes. The mistake grows in the gap between them. ## How does AdBlue in your diesel tank occur in Whitnash? Three things tend to line up, and carelessness is seldom one of them. The warning comes first. As AdBlue runs low the vehicle tells you, and if it runs out altogether, the vehicle drops into limp mode. So the top-up is done in a hurry: on a driveway off Acre Close before work, or in the car park at The Plough and Harrow on the way home. The old car's cap is where your hand goes — but a rental car, a new motor or a company car puts the fillers somewhere else. That's the second factor: a new car. Third, the spout fits: diesel filler or AdBlue one, it slides in as easily, and once the pour starts, nothing stops it. The same few seconds decide it, in the middle of Whitnash or out in Sydenham. ## The AdBlue filler and the diesel filler: telling them apart A few seconds is all the checks take — so run through them before you pour anything, on a driveway in Bishops Tachbrook or a forecourt around Whitnash. - Read the cap rather than going by where it sits: AdBlue ones are regularly blue or marked "AdBlue", and diesel ones usually are not. - The size. On many cars the AdBlue filler neck is the smaller of the two. - The flap. Look inside your fuel flap for a label. Many motors say there which fuel goes where. - The handbook. If your filler is not by the diesel cap, it's in your boot or under the bonnet, and the handbook says which. - The previous driver knows. Check as you pick up a rental or company car — from Leamington Spa's car park, say — not when the warning appears. ## Keeping AdBlue out of your diesel tank when you top up For the day the warning comes on — anywhere you are around Warwickshire — a simple routine to follow. - Park then switch off. Not on a slope, not with your motor running, and not in a rush on the side of Heathcote Road. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds silly and it does the trick. - The diesel cap remains on. Where the two share a flap, confirm it is shut before the bottle comes up. - Using the bottle's own spout, tip slowly — and stop when it's full or the bottle is empty. - Shut the cap, then check again — making sure the diesel filler stayed closed the whole time. Only then, start your car. Stop there if you find, at stage two or three, that you've already poured into the diesel side. Leave out step five altogether. ## Already put AdBlue in the diesel tank in Whitnash? What follows is a short order of things, starting with not starting the engine. Keep your ignition off too, since on many diesels it alone starts the pump. Thinning it with extra diesel fails, because AdBlue settles to the bottom rather than blending — and that's where the fuel is pulled from. The staff at Asda, Sainsbury's or any forecourt will normally help pushing your car away if asked. If you are on your own driveway around Whitnash, leave the car where it is. If the engine has already run, stop as soon as it is safe and switch off. On the M40, under 3 miles from Whitnash, that means the next junction. Tell us about how far it went: a run towards Coventry, under 10 miles away, is a bigger job than a short hop across Whitnash. ## Our arrival in Whitnash, and what occurs next The van comes to the vehicle wherever it stopped — your own driveway, beside Whitnash Sports & Social Club, or outside Whitnash Primary School. Those replies settle the work and our quote, and so our engineers ask what went in, roughly how much, and whether it has run. On the phone call itself, you are told the price — before anything else. Draining the tank comes next, then a full flush of the fuel system. With AdBlue that counts 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. The filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and the car is tested. The engine is fired up next and checked to confirm it runs correctly, all before our engineers head off. Most jobs are done in about half an hour once our technicians arrive, as long as the motor hasn't run — and the pumps our engineers use are safe on a live forecourt and quiet at night outside a house. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Many insurance policies include misfuelling cover, and so it is worth checking yours while we're on the way. ## About Whitnash Whitnash is a town situated in a riverside location in Warwickshire, England, lying close to Leamington Spa and Warwick. It forms part of a larger urban area, with its boundaries blending into those of neighbouring towns. The town is nestled in a scenic spot, with the river nearby adding to its charm. Whitnash is a notable settlement in the region, with a distinct character shaped by its surroundings. ## AdBlue drains across Warwickshire, Whitnash included Being a riverside town, Whitnash shares its vans nearby places — Tachbrook Mallory, Myton — all the way through CV postcodes and the surrounding area beyond. Quote a postcode that starts CV31 2, and the van arrives quickest. The car does not need to move. Wherever it stands — beside Whitnash Library, on a layby en route to Acre Close, at home — that is where it gets emptied. Ring and ask instead of guessing if you're near a boundary, or somewhere hard to describe, like the back of Whitnash Town Council. ## The short version for Whitnash motorists Read the cap before you tip. Petrol in Diesel drains it on the spot, anywhere around Warwickshire, if AdBlue has gone in your diesel tank anyway — and so leave it off and ring 0333 366 0103.