--- title: Explained: AdBlue in a Diesel Tank Blackness canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/blackness-east-sussex/ location: Blackness county: East Sussex latitude: 51.050720 longitude: 0.171480 service: AdBlue in a Diesel Tank updated: 2026-10-09 --- # Avoiding AdBlue in a Diesel Tank in Blackness: Why It Occurs AdBlue already in your diesel tank? Then set this page down for now, keep the ignition and motor off, then phone 0333 366 0103. In Blackness, finding it before the engine turns normally leaves a drain and a thorough flush on the spot. Not happened yet? Further down, the page explains the why it occurs and the ways to avoid it altogether. ## Two fillers, two tanks: AdBlue in a diesel vehicle Not one fluid but two: that is how many modern diesels near Blackness and Crowborough run, with diesel for the motor. AdBlue goes to your exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Separate tanks, separate fillers. Plenty of motors have a single flap for the two, whereas others move the AdBlue filler to the boot or under the bonnet. Diesel goes in on every filling station call-out, week in, week out. Far less often, the AdBlue side is topped up — mostly from a bottle, by someone thinking about where it goes. The mistake grows in that gap between the two. ## How does AdBlue in your diesel tank happen around Blackness? Three things tend to come together, and carelessness is rarely one of them. First, the warning. Low AdBlue brings a warning from your car, and running out means limp mode — so a rushed top-up, perhaps before work off Montargis Way, perhaps outside The White Hart on the way home after work. Then, your hand reaches for the cap it knew on the old vehicle — since a hire car, a new car or a company car places the fillers somewhere your last one did not. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, so nothing stops the tip after it has started. It takes a few seconds, be it out in Whitehill or bang in the centre of Blackness. ## Telling the AdBlue filler from the diesel filler Check these before pouring, at a forecourt around Blackness or a drive out in Jarvis Brook. A few seconds, no more. - Position can mislead; the cap doesn't. AdBlue caps are often blue or bear the word "AdBlue" — diesel caps normally do not. - Plenty of vehicles give AdBlue the smaller neck of the two. - Lift the flap and check for a label — many vehicles mark what belongs in which filler just there. - The handbook says where it is if the filler isn't next to your diesel cap: the boot, or under the bonnet. - Check with the person who drove it last — before you leave, not when the light comes on — if you pick up a hire or company car from somewhere like the car park outside Crowborough. ## Keeping AdBlue out of the diesel tank when you top up On the day the light comes on — anywhere it is in East Sussex — a simple routine to use. - Pull in on level, motor off, with time to spare — never hurried on the side of Buller Close. - Find the AdBlue filler, read the cap, and speak the word "AdBlue" out loud as unscrewing it. It seems daft. It works. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave the vehicle on. - Using the bottle's own spout, pour slowly — and stop when it's full or the bottle is empty. - Close the cap, then check again — confirm your diesel cap stayed shut throughout. After that, start the vehicle. Find at the second or third stage that the bottle went in the diesel filler? That is where you stop. Leave out step five entirely. ## AdBlue in the diesel tank already, around Blackness? Short order, then. Top of that: your engine stays unstarted. Keep your ignition off too, since on plenty of diesels it alone runs your fuel pump. AdBlue does not mix with diesel — it sinks to the bottom of that tank, where the fuel is pulled from — so don't top up with diesel to thin it. Ask the staff to help roll your car clear of the pump if you are on a forecourt — the BP, the Esso or somewhere else. Leave it where it is if you are on your own drive in Blackness. If the motor has already run, stop as soon as it is safe then switch off. On the M23, under 15 miles from Blackness, that means the next junction. Tell us roughly how far it went: a run towards Brighton and Hove, under 25 miles away, is a bigger job than a short hop across Blackness. ## What takes place when our technicians turn up in Blackness Outside Ashdown Primary School, near St Mary's Catholic Church or on your own drive: wherever the car has stopped, our technicians come to it. The replies determine the work and our price, and so our engineers ask what got in, roughly how much, and whether it's run. During the phone call itself, you are told our price — before anything else. Emptying the tank comes next, then a full flush of your system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own — which is why the flush matters more with AdBlue than with petrol. A test is at the end: before that, clean diesel goes in, and the fuel filter is cleaned or replaced if necessary. The motor is started next and checked to be sure it runs correctly, all before our engineers leave. If the engine has not run, most jobs take about half an hour once we are there, using pumps that are safe on a working forecourt and quiet enough to use outside a house after dark. Paying happens on the day, not upfront, and you receive the paperwork your insurer wants: an engineer report and a VAT invoice. It is worth looking at your insurance as the van travels to you: misfuelling cover comes with many policies. ## About Blackness itself Blackness is a suburban area in East Sussex, situated inland at an elevation of 178 metres, and is located near the communities of Whitehill, Poundfield, and Alderbrook. Blackness has a population of approximately 5205 residents and is characterized by predominantly detached housing. Blackness is positioned about 20.8 miles from Brighton and Hove and 34.1 miles from London, placing it within the wider South East region. Blackness sits in a area of gently rolling hills and countryside, typical of the East Sussex landscape. ## AdBlue drains across East Sussex, Blackness included Being a residential suburb, Blackness has the same vans as nearby places — Poundfield, Alderbrook — all the way through TN postcodes and the surrounding area around them. Quote a postcode beginning TN6 2, and our van gets there quickest. The car does not need to shift. A driveway, a lay-by on the way to Wolfe Recreation Ground, a side street near Rock Snake: we drain the car where it sits. Ring and ask instead of guessing if you are close to a border, or somewhere hard to explain, like the back of All Saints Crowborough. ## The short version for Blackness drivers Pour nothing till you've read the cap. AdBlue in the diesel tank regardless? Leave the vehicle switched off then phone 0333 366 0103; Petrol in Diesel drains it where it stands, across East Sussex.