--- title: AdBlue in a Diesel Tank Sparry Bottom? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/sparry-bottom-cornwall/ location: Sparry Bottom county: Cornwall latitude: 50.228130 longitude: -5.176180 service: AdBlue in a Diesel Tank updated: 2026-10-04 --- # Why It Occurs and How to Prevent It: AdBlue in a Diesel Tank in Sparry Bottom If AdBlue is already in your diesel tank, stop reading for a moment: leave the motor and your ignition off and call 0333 366 0103. A drain and a thorough flush, carried out right where your car stands around Sparry Bottom, is normally all it takes when caught before your motor runs. Not happened yet? Below, the page covers the why it takes place and the how to avoid it altogether. ## Two fillers, two tanks: AdBlue in a diesel motor Diesel feeds your engine — but plenty of modern diesels seen about Sparry Bottom and Tolcarne hold a second fluid too. AdBlue goes to the exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Separate tanks, different fillers. Some vehicles put the AdBlue filler in your boot or under the bonnet; a lot more place both together under one flap. Topping up your diesel side at the pump goes on constantly. Someone who has to stop and think where it goes normally fills the AdBlue side, from a bottle, and far less often. That gap is where the mistake lives. ## How does AdBlue in the diesel tank occur around Sparry Bottom? Carelessness rarely causes it. Instead is three things lining up at once. On a driveway off Sparry Lane before work, or in the car park outside St Day Inn on the way home: that is where the rushed top-up takes place. What is the reason for the rush? As AdBlue runs low your car tells you, and if it's gone, limp mode kicks in. Next, the hand goes for the cap it knew on the old car — because a rental car, a new car or a company car puts the fillers where your last one did not. A spouted bottle finds no resistance at a diesel filler any more than at an AdBlue one. And so the tip, once begun, carries on. It's seconds, whether in Carharrack or right in the centre of Sparry Bottom. ## Telling the AdBlue filler from the diesel filler Before you pour anything, whether on a drive in Crofthandy or a forecourt in Sparry Bottom, check these. They take a few seconds. - Position misleads; the cap doesn't. AdBlue ones are often blue or bear the word "AdBlue" — diesel caps usually do not. - The size. On plenty of 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 isn't by the diesel cap, it's in the boot or under the bonnet, and the handbook says which. - Ask 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 Redruth. ## Topping up AdBlue without it reaching your diesel tank When the light comes on, anywhere around Cornwall, follow this routine. - Park then switch off. Not on a slope, not with your engine running, and not in a rush on the side of Poldory Meadows. - Silly as it sounds, saying "AdBlue" aloud as you unscrew the cap works — once you have found the filler and read the cap. - Leave your diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Finish when the tank is topped up or the bottle is empty; until then, tip slowly using its built-in spout. - Before starting the vehicle, shut the cap and look again that your diesel cap was never came off. Stop there if you find, at stage two or three, that you have already poured into the diesel side. Skip step five altogether. ## Already put AdBlue in your diesel tank in Sparry Bottom? The short order of things, starting with not starting the motor. The fuel pump runs on plenty of diesels as soon as your ignition goes on — so leave it off. Don't top up with diesel to dilute it: AdBlue does not mix with diesel, it sinks to the bottom of that tank, where your fuel is pulled from. The staff at Shell, Texaco or another forecourt will normally lend a hand pushing your car clear if asked. If you're on your own drive in Sparry Bottom, leave the vehicle where it stands. If the engine has already run, stop as soon as it is safe and switch off. On the M5, over 50 miles from Sparry Bottom, that means the next exit. Tell us about how far it went: a run towards Truro, under 10 miles away, is a bigger job than a short hop across Sparry Bottom. ## What happens when our engineers turn up around Sparry Bottom The van comes to your car anywhere it stopped — your own drive, beside St Piran Mission Church, or by St Day and Carharrack Community School. Our technicians ask what went in, about how much, and if it has run, since the replies decide this work and the price. During the phone call itself, you hear our price — before anything else. The system is then rinsed thoroughly, once your tank is cleared. More than with petrol, it matters with AdBlue: the crystals form, some metals corrode, and none of that clears out on its own, no matter how long it is left. The filter cleaned or, where needed, replaced; fresh diesel in; and then a check of the vehicle. Before we leave, our engineers fire it up and confirm that it is running smoothly. Unrun vehicles mostly mean a half-hour visit from the moment we arrive. The equipment is safe on a busy filling station, and quiet enough for a driveway late at night. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Before we get there, take a look at your insurance documents; many include cover for misfuelling. ## About Sparry Bottom and where it is Sparry Bottom is a small hamlet in Cornwall, situated inland at an elevation of 78 metres, approximately 6 miles from the city of Truro. Sparry Bottom lies near the villages of Carharrack and Trevarth, and the rural area of United Downs. Sparry Bottom is characterized by its predominantly detached housing stock, reflecting its rural setting. Sparry Bottom is located in the South West region of England, about 237 miles west of London. ## AdBlue drains across Cornwall, Sparry Bottom included Throughout TR postcodes, the vans that cover Sparry Bottom — a rural hamlet — work the surrounding places too, Trevarth and United Downs among them. The van reaches you fastest with a postcode starting TR16 5. The vehicle remains put. A driveway, a lay-by on the way to Carharrack Playing Field, a side street near Carharrack Methodist Chapel: our engineers drain the vehicle where it sits. Guessing won't help at the back of St Day Old Church, close to a boundary, or somewhere hard to describe; phone and ask. ## The short version for Sparry Bottom drivers Pour no AdBlue until you have read the cap. Still AdBlue in the diesel tank? Petrol in Diesel will drain it wherever it is, anywhere around Cornwall: keep the vehicle off then phone 0333 366 0103.