--- title: AdBlue in a Diesel Tank Biscovey: Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/biscovey-cornwall/ location: Biscovey county: Cornwall latitude: 50.349540 longitude: -4.721220 service: AdBlue in a Diesel Tank updated: 2026-10-14 --- # AdBlue in a Diesel Tank in Biscovey: Why It Happens and How to Avoid It AdBlue already in your diesel tank? Then set this page aside for now, keep the ignition and engine off, then ring 0333 366 0103. In Biscovey, finding it before the engine runs normally means draining and a thorough flush on the spot. If you are reading before it has happened, the rest of this page is about why it takes place and how to make sure it does not. ## Two fillers, two tanks: AdBlue in a diesel motor Many newer diesels in Par, as well as Biscovey, carry on two liquids; your motor takes just the diesel. The exhaust, not your motor, is where AdBlue goes: dosed into the gas to fresh them, from its own tank. Each tank comes with a filler of its own. Under one flap, side by side: that's the arrangement on many vehicles. Elsewhere, AdBlue's filler is under the bonnet or in the boot instead. Topping up your diesel side at the petrol pump happens constantly. Rarely filled, AdBlue usually comes out of a bottle, poured by a driver who has to stop and think what cap it needs. The mistake lives in that gap. ## AdBlue in your diesel tank around Biscovey: how it occurs Three things tend to come together, and carelessness is rarely one of them. On a driveway off Lamellyn Road before work, or in the car park at The Four Lords on the way home: that is where the hurried top-up takes place. What is the reason for the rush? As AdBlue runs low your car warns you, and once it is empty, limp mode kicks in. New-to-you motors are next, as well. Rentals, new cars and company cars put their fillers in new places, and the hand goes for the cap used on the old one. A spout-topped bottle finds no resistance at a diesel filler no more than at an AdBlue one. So the pour, once started, keeps on. It takes a few seconds, whether out in St Blazey Gate or bang in the heart of Biscovey. ## The AdBlue filler and your diesel filler: telling them apart Check these first, on a forecourt in Biscovey or a driveway over in Kilhallon. Seconds, no more. - Check the cap instead of going by where it sits: AdBlue ones are commonly blue or marked "AdBlue", and diesel ones normally aren't. - The size. On many motors the AdBlue filler neck is the smaller of the two. - Open the filler flap and check for a label — plenty of vehicles show which belongs in each filler just there. - Cannot find it beside the diesel filler? Then check below the bonnet or in your boot — the owner's manual will say where. - Picking up a hire or company car, perhaps at the car park outside Par? Ask the person who drove the vehicle last before you set off, rather than when the light comes on. ## Topping up AdBlue without it reaching the diesel tank When the light comes on, anywhere across Cornwall, use this routine. - Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of Trenython Road. - Locate the AdBlue filler, read the cap, and speak the word "AdBlue" out loud as unscrewing it. It seems silly. It works. - The diesel cap remains on. Where both sit under a flap, make sure it's closed before lifting the bottle. - Pour slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Close the cap and check once more. Make sure your diesel cap was never opened. Only then start the car. Spot at step two or three that it has already gone into the diesel side? So stop right there. Do not go on to stage five. ## Already put AdBlue in your diesel tank around Biscovey? What follows is a short order of things, starting with no starting the engine. Leave the ignition off as well, because on plenty of diesels it by itself starts your fuel pump. Do not top up with diesel to thin it: AdBlue does not mix with diesel, it sinks to the bottom of your tank, where your fuel is pulled from. If you're on a forecourt, whether it's the BP or the Gulf, ask the attendants to help roll the vehicle away from the petrol pump. Your own driveway in Biscovey is where it should stay. Where the engine has been run by now, stop safely and turn the car off. Biscovey lies over 50 miles from the M5; on it, use the next junction. Mileage counts — a short hop across Biscovey makes a smaller job than heading under 25 miles towards Truro — so say about how far it went. ## Biscovey: what takes place when our engineers arrive Anywhere the vehicle came to rest, be it by Biscovey Academy, near Kingdom Hall of Jehovah's Witnesses or on your own drive, our van comes to it. Both the work and the price depend on three answers — what liquid, which quantity, and if it has run — so our technicians ask. During the call itself, you are told the quote — before anything else. Draining your tank comes next, then a thorough flush of the system. More than with petrol, it matters here: crystals build up, some metals are attacked, and none of it washes away on its own, no matter how long it is left. The filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and your car is tested. Before we leave, we fire it up and check that it's running smoothly. With pumps fine on a busy forecourt and quiet enough for use outside a house at night, most jobs in which your motor has not run need roughly half an hour once our technicians are there. No money in advance; you settle up on the day. Afterwards, the VAT invoice and a report from the engineer are handed to you for the insurer. Wrong-fuel cover is included in many insurance policies — and so make use of the wait to check yours. ## About Biscovey, briefly Biscovey is a coastal locality in Cornwall, situated near the town of Par and the village of St Blazey, at an elevation of 34 metres above sea level. Biscovey lies within a short distance of several nearby places, including St Blazey Gate, St Blazey, and Bodelva. Biscovey is characterised by its semi-detached housing stock and is located approximately 15.7 miles from the city of Truro. Biscovey has a population of around 2524 residents. ## AdBlue drains across Cornwall, Biscovey included Throughout PL postcodes, the vans covering Biscovey — a coastal area — work the nearby spots too, Bodelva and St Blazey among them. Give a postcode beginning PL24 2, and the van arrives fastest. The vehicle doesn't need to move. Our technicians drain it where it is — a side street near St Mary the Virgin, Par, a lay-by on the way to St Mary's Recreation Ground, a drive. Ring and ask instead of guessing if you're near a border, or somewhere hard to describe, like the back of Mid Cornwall Galleries. ## In short, for Biscovey drivers Before you pour, read the cap. Even so AdBlue in your diesel tank? Petrol in Diesel can drain it where it stands, anywhere around Cornwall: keep it off then ring 0333 366 0103.