--- title: AdBlue in a Diesel Tank Capecastle? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/capecastle-county-antrim/ location: Capecastle county: County Antrim latitude: 55.165830 longitude: -6.295560 service: AdBlue in a Diesel Tank updated: 2026-10-16 --- # Capecastle: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? If AdBlue is already in your diesel tank, stop reading for a moment: leave your engine and the ignition off and phone 0333 366 0103. Normally, if the motor has not turned, it is emptied and thoroughly rinsed where your vehicle sits in Capecastle. Not happened yet? Below, the page explains the reasons it takes place and the ways to prevent it for good. ## AdBlue in a diesel vehicle: two tanks, two fillers Not one liquid but two: that is what many modern diesels around Capecastle and Ballyvoy run, with diesel feeding your motor. AdBlue goes to the exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Each tank has its own filler. Many of cars share a single flap for the two, while others put the AdBlue filler to the boot or under the bonnet. The diesel side is topped up at the petrol pump all the time. Someone who has to stop and work out where it goes normally fills the AdBlue side, from a bottle, and much less regularly. It is in the gap that the mistake happens. ## AdBlue in your diesel tank around Capecastle: how it takes place It's seldom carelessness. Three things tend to line up. The warning comes first. As AdBlue runs low the car tells you, and if it runs out completely, the vehicle drops into limp mode. So the top-up is done in a hurry: on a driveway off B842 before work, or in the car park outside the pub in the village on the way home. The old car's cap is where the hand reaches — but a rental car, a new car or a company car keeps the fillers elsewhere. That's a second thing: a strange car. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, so nothing stops the pour after it has started. It's seconds, whether out in Armoy or bang in the heart of Capecastle. ## The AdBlue filler and the diesel filler: telling them apart Check these first, on a forecourt in Capecastle or a drive over in Portbraddon. Seconds, no more. - Blue and lettering: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap usually does not. Go by the cap, not where it sits. - Look at the size: the smaller neck is, on plenty of motors, the AdBlue one. - The flap. Look inside your fuel flap for a label. Plenty of vehicles say there which fuel goes where. - The handbook. If your filler isn't by the diesel cap, it is in your boot or under the bonnet, and the handbook says which. - The previous driver knows. Check when you pick up a hire car or fleet car — at the nearest station's car park, perhaps — not when the warning comes on. ## AdBlue top-ups that never reach your diesel tank Anywhere across County Antrim the light comes on, here is a routine for the day. - Stop on level, engine off, with time in hand — not hurried on the side of Dunaverty Court. - Find the AdBlue filler, check the cap, and say the word "AdBlue" aloud as you unscrew it. It sounds daft. It does the trick. - The two behind a single flap? So make sure the cap on the diesel filler is still closed before raising the bottle. - Tip slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty. - Close the cap and check a second time. Make sure the diesel cap was never opened. Only then start the vehicle. Find at step two or three that it's already gone into your diesel side? So stop right there. Never go on to step five. ## AdBlue in the diesel tank already, in Capecastle? Do not start the engine: that's where the short order of things starts. The fuel pump starts on many diesels as soon as the ignition is switched on — so keep it off. Filling up with diesel won't thin it: rather than mixing, AdBlue sinks to the bottom of your tank, just where fuel is taken from. If you're on a forecourt, whether it is the the nearest petrol station or the another forecourt nearby, ask the staff to help push the car away from the petrol pump. At home around Capecastle? Then your car remains where it is. When your engine has run already, stop safely and switch the car off. The next junction is where to leave if you are on the M77, over 50 miles from Capecastle. Roughly how far did it go? Crossing Capecastle is less a job than a trip of under 50 miles towards Derry, so tell us. ## Capecastle: what takes place when our technicians turn up Wherever your car has stopped, whether by the local primary school, beside the centre or on your own drive, our van travels to it. Which liquid got in, the amount, and if it ran: we ask because the replies set the work and quote. The quote is given over the phone, before any van leaves. Then the tank is cleared and the system rinsed thoroughly. Not like petrol, AdBlue leaves crystals and eats at some fuel-system metals, and neither washes out unaided. Hence it counts more. Filter flushed or, where needed, swapped; clean diesel in; then a test of the vehicle. After that we start it and make sure it runs correctly before we leave. Using pumps safe on a working forecourt and quiet enough for use outside a house at night, most jobs where the motor has not run take roughly half an hour once our engineers arrive. Your insurer usually wants the engineer's report and the VAT invoice, and both are yours once this job is done. Payment is on the day, with no deposit. Misfuelling cover is part of plenty of insurance policies — so make use of the wait to check yours. ## About Capecastle itself Capecastle is a small locality in County Antrim, situated inland at an elevation of 101 metres. Capecastle lies near the villages of Armoy and Ballycastle, and is approximately 41 miles from Derry. Capecastle has a population of around 520 people, predominantly living in detached housing. Capecastle is part of the wider rural landscape of Northern Ireland, with Moss-Side nearby. ## Capecastle and County Antrim: AdBlue drains across the area Throughout BT postcodes, the vans that cover Capecastle — a small village — work the nearby locations too, Moss-Side and Ballycastle among them. Give a postcode that starts BT54 6, and our van arrives quickest. The car remains where it is. Anywhere it sits — near a street just off the centre, in a lay-by heading to the green space at the edge of the village, at home — that is where it gets cleared. Tricky to explain, like the back of the far end of the built-up part? Close to a border? Checking beats guessing, so phone. ## Capecastle motorists: the short version Tip no AdBlue until you have read the cap. AdBlue in your diesel tank regardless? Keep the car off then ring 0333 366 0103; Petrol in Diesel empties it on the spot, throughout County Antrim.