--- title: Budock Water: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/budock-water-cornwall/ location: Budock Water county: Cornwall latitude: 50.149570 longitude: -5.103160 service: AdBlue in a Diesel Tank updated: 2026-10-03 --- # Budock Water: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? Leave your motor and ignition off and call 0333 366 0103 first — reading can wait if AdBlue is already in your diesel tank. Caught before the motor runs, it's normally a drain and a thorough flush, done where your car is in Budock Water. If you are reading before it has happened, the rest of this page is about why it happens and how to make sure it does not. ## Why does AdBlue in a diesel car need its own filler? Diesel feeds the motor — but many modern diesels seen round Budock Water and Golden Bank hold another liquid as well. Kept in a tank of its own, AdBlue is fed into the exhaust stream and cleans it. There is a filler for each tank. Plenty of cars have a single flap for both, whereas some put the AdBlue filler to the boot or under the bonnet. The diesel side is fuelled at the petrol pump all the time. A driver who has to stop and work out where it goes normally tops up the AdBlue side, from a bottle, and far less often. It is in the gap that the slip happens. ## How does AdBlue in the diesel tank take place around Budock Water? It's seldom carelessness. Three things tend to line up. On a driveway off Little Nangitha before work, or in the car park at Trelowarren Arms heading home: that's where the rushed top-up happens. What is the reason for the rush? As AdBlue gets low the vehicle tells you, and once it's empty, limp mode follows. Unfamiliar motors come second, too. Rentals, new motors and company cars put their fillers differently, and habit reaches for the cap used on the old one. Lastly, the bottle fits: diesel filler or AdBlue one, it goes in just as easily, and once the tip begins, no part halts it. The same few seconds settle it, in the middle of Budock Water or out in Mongleath. ## Which filler is for AdBlue, and which for diesel? Before you tip anything, whether on a driveway in Twinbrook Park or a forecourt in Budock Water, check these. They take a few seconds. - The cap. The AdBlue cap is frequently blue, or marked "AdBlue". The diesel cap usually is not. Read it rather than going by where it sits. - Check the size: the smaller filler neck is, on many vehicles, the AdBlue one. - A label inside your fuel flap frequently shows which fuel goes where, on many vehicles. Look for it. - 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 it last. On a hire or company car collected from somewhere like the car park at Penmere, ask before you leave, not when the light comes on. ## AdBlue top-ups that never reach your diesel tank Wherever around Cornwall the light comes on, here is a routine for that day. - Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of School Hill. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it does the trick. - Leave the diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Pour slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty. - Shut the cap, then look again — confirm your diesel filler stayed shut the whole time. After that, start the car. If at stage two or three you find you have already poured into your diesel side, stop there. Leave out stage five entirely. ## Budock Water: already put AdBlue in your diesel tank? Brief order, then. Top of it: the motor stays off. The fuel pump runs on many diesels as soon as your ignition goes on — and so keep it off. Filling up with diesel will not weaken it: rather than mixing, AdBlue drops to the base of that tank, just where the fuel is taken from. The attendants at the nearest petrol station, Esso or any forecourt will normally help to push your car away when asked. On your own drive in Budock Water? Then the car remains put. If the motor has already run, stop as soon as it is safe and switch off. Leave the M5 — over 50 miles out of Budock Water — at the next junction. A short hop across Budock Water is a smaller job than a run towards Truro, under 10 miles away, so tell us about how far it went. ## What takes place when our engineers arrive in Budock Water Our van comes to the vehicle wherever it stopped — your own drive, beside Budock Village Hall, or outside St Francis CofE Primary School. Those replies decide this work and the quote, so our engineers ask what went in, about how much, and if it's run. No one sets off until you've heard the quote over the phone. Then that tank is emptied and your system purged 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. A test comes last: before that, clean diesel is added, and the fuel filter is cleaned or replaced if necessary. The motor is fired up next and tested to confirm it runs properly, all before our technicians head off. If the engine has not run, the majority of jobs take about half an hour once we're there, using pumps that are safe 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 wants: an engineer's report and a VAT invoice. Plenty of insurance policies include misfuelling cover, so it is worth checking yours while we're on the way. ## About Budock Water Budock Water is a village in Cornwall, situated near the coast and approximately 8 miles from Truro. Budock Water sits at an elevation of around 66 metres, overlooking the surrounding countryside. Budock Water is characterised by its predominantly detached housing stock, with nearby places including Mongleath, Boslowick, and Swanvale. Budock Water has a population of around 1083 residents. ## AdBlue drains around Budock Water and across Cornwall Budock Water is a coastal village, and the teams that cover it also work the places around it, Boslowick and Swanvale among them, across the TR postcode area. Fastest of all: quote a TR11 5 postcode to our van. Your car does not need to shift. Our technicians drain it where it is — a side street close to Budock Parish Church, a lay-by on the way to Play Area, a driveway. Assuming doesn't help behind Bickland Park, on a boundary, or anywhere hard to describe; phone and ask. ## In short, for Budock Water drivers Read the cap before you pour. Even so AdBlue in the diesel tank? Petrol in Diesel can drain it where it is, wherever in Cornwall: switch the car off and phone 0333 366 0103.