--- title: AdBlue in a Diesel Tank St Keverne? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/st-keverne-cornwall/ location: St Keverne county: Cornwall latitude: 50.049400 longitude: -5.089330 service: AdBlue in a Diesel Tank updated: 2026-10-28 --- # AdBlue in a Diesel Tank in St Keverne: Why It Occurs and How to Prevent It Stop reading a minute if the diesel tank already has AdBlue in it: ignition off, motor off, then phone 0333 366 0103. A drain and a thorough flush, carried out just where your vehicle stands in St Keverne, is usually all it takes if found before the engine runs. Not happened yet? Further down, the page explains the reasons it takes place and the ways to avoid it for good. ## AdBlue in a diesel vehicle, and its separate tank No single fluid but two: that's what plenty of modern diesels around St Keverne and Trenance run, with diesel for the motor. Your exhaust, not the engine, is where AdBlue goes: sprayed into the fumes to fresh it, from its own tank. Each tank has its own filler. Under one flap, side by side: that is the arrangement on a lot of cars. Elsewhere, AdBlue's filler sits beneath the bonnet or in the boot instead. At the pump, your diesel side is topped up all the time. Rarely topped up, AdBlue usually comes from a bottle, tipped by a driver who has to stop and think what filler it needs. Mistakes happen in the gap between them. ## St Keverne: how AdBlue in your diesel tank happens Three things tend to line up, and carelessness is rarely one of them. The warning comes first. As AdBlue runs low the 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 B3293 before work, or in the car park at The White Hart on the way home. Then the car is new. A hire car, a new motor or a company car puts the fillers where your last one didn't, and the hand hits for the cap it would have used on the old one. A spouted bottle finds no resistance at a diesel filler no more than at an AdBlue one. So the pour, once started, carries on. Laddenvean or the heart of St Keverne: it takes the same few seconds in both. ## Which filler is for AdBlue, and which for diesel? A couple of seconds is all these take — so check them before you pour anything, on a driveway in Porthoustock or a forecourt in St Keverne. - Blue and marking: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap usually doesn't. Go by the cap, not where it sits. - On many cars, size gives it away: AdBlue gets the smaller filler neck. - Look inside your fuel flap: plenty of vehicles have a label there saying which fuel goes where. - The handbook shows where it lives if the filler is not next to your diesel cap: the boot, or under the bonnet. - Whoever had it before knows. Check as you collect a rental or company car — at Falmouth Town's car park, say — rather than when the warning appears. ## How to top up without AdBlue in the diesel tank On the day the warning comes on — anywhere it is across Cornwall — a simple routine to use. - Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of High Street. - Find the AdBlue filler, check the cap, and say the word "AdBlue" out loud while unscrewing it. It sounds silly. It works. - Leave your diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Using the bottle's own spout, tip slowly — and stop when it is full or the bottle is empty. - Before you start the vehicle, shut the cap and look again that the diesel cap was never came off. Stop there if you find, at stage two or three, that you've already poured into the diesel side. Don't go on to step five. ## AdBlue in your diesel tank already, in St Keverne? Do not start your motor: that's how the short order of things starts. The fuel pump runs on many diesels the moment your ignition goes on — so leave it off. AdBlue does not mix with diesel — it sinks to the bottom of that tank, where the fuel is sucked from — so don't top up with diesel to dilute it. If you are on a forecourt, whether it is the the nearest petrol station or the another forecourt nearby, ask the staff to help push the vehicle away from the petrol pump. Your own driveway around St Keverne is where it should stay. Already run? Pull over once it's sensible, then switch off. Leave the M5 — over 50 miles out of St Keverne — at the first junction. A short hop across St Keverne is a smaller job than a run towards Truro, under 15 miles away, so tell us roughly how far it went. ## St Keverne: what occurs when our engineers turn up Our van comes to the car wherever it has come to rest — your own driveway, near St Keverne Parish Hall, or outside St Keverne Primary School. Both the work and our quote rest on three replies — which liquid, which quantity, and whether it has run — so our technicians ask. During the phone call itself, you hear our price — before dispatch. Then the tank is cleared and your system rinsed thoroughly. 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 does not wash out on its own. The filter flushed or, where it must be, replaced; fresh diesel in; then a check of your car. Your engine is started next and checked to make sure it runs smoothly, all before our engineers head off. If your engine has not run, most jobs take about half an hour once we are there, using pumps that are fine on a busy forecourt and quiet enough to use outside a house at night. Payment happens on the day, not upfront, and you receive the paperwork an insurer asks for: an engineer report and a VAT invoice. While we travel, have a look at your policy; many include cover for misfuelling. ## About St Keverne itself St Keverne is a coastal village in Cornwall, situated on the Lizard Peninsula at an elevation of around 92 metres. St Keverne lies near the villages of Laddenvean and Rosenithon, and is approximately 14.9 miles from the city of Truro. St Keverne has a population of around 697 people, predominantly living in semi-detached housing. ## AdBlue drains round St Keverne, and Cornwall beyond Rosenithon and Tregarne are among the towns near St Keverne, a coastal village, that the same teams cover, throughout TR postcodes. Fastest of all: quote a TR12 6 postcode for the van. The vehicle stays where it is. The drain takes place on the spot, be it a driveway, a street near St. Keverne Parish Church, or a layby towards Three Tuns. Ring and ask instead of guessing if you're close to a boundary, or somewhere hard to explain, like the back of Church Hall. ## In short, for St Keverne motorists Tip nothing till you have read the cap. Still AdBlue in your diesel tank? Petrol in Diesel will empty it wherever it is, wherever around Cornwall: switch it off then call 0333 366 0103.