--- title: AdBlue in a Diesel Tank Mountjoy — Don't Start It canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/mountjoy-county-tyrone/ location: Mountjoy county: County Tyrone latitude: 54.550000 longitude: -6.600000 service: AdBlue in a Diesel Tank updated: 2026-10-19 --- # Mountjoy: AdBlue in the Diesel Tank? Leave It Off If AdBlue has got into your diesel tank, leave your engine off then leave your ignition off. Water with urea mixed in it: that is AdBlue. It does not burn, it does not mix with diesel, and the harm it does starts when the fuel system pulls it in. Caught before your motor has run, AdBlue in a diesel tank is normally a drain and a thorough flush, done where the vehicle is around Mountjoy. Before you do anything else, call 0333 366 0103. ## Those opening minutes: AdBlue in your diesel tank in Mountjoy To do: - So nobody can turn your ignition on, take the keys away. - Put the hazards on if you're at all close to moving traffic. - Which fluid, and about what amount? Save the bottle or the till receipt, and we can know. - The van finds you quickest with a postcode starting BT71 5, or simply the name of a street nearby, so phone from the spot. Don't: - Moving the vehicle even a short way is no reason to fire up your motor. - The ignition stays off: on lots of diesels, switching it on is enough to run your fuel pump. - AdBlue does not dilute in diesel — it separates out — so adding more fuel won't weaken it. - Even a short way down Heugh Road is too far to drive the car. - Beside the road, don't try draining it on your own. Ask the attendants to help you move your car off the island if you are at a forecourt around Mountjoy, whether it is the the nearest petrol station or somewhere else. At your own drive, do not move it at all. ## AdBlue in a diesel tank: what it does AdBlue is made for the exhaust, not your engine. From a separate reservoir it is fed directly to your exhaust, cleaning what the engine emits. Nothing in it is supposed to pass through a fuel pump, and nothing in a fuel pump is made to handle it. Fuel blends; AdBlue, after tipped in, will not. The behaviour is nothing like diesel's. It is heavier than diesel, so it sinks and gathers at the bottom of that tank, which is where the pickup sucks fuel from. A car topped up on a driveway in Maghery overnight and left unstarted is the straightforward one. No pump has pulled the AdBlue up so far — though when your motor runs, that's what is pulled first, directly from the bottom of the tank. Two kinds of harm come from there. What remains when the water goes is urea, which turns into crystals: they lodge in tiny channels and block filters. On top of that, it eats at certain metals in the fuel system, and carries on till it is cleared out. Overnight, a car parked around Mountjoy with AdBlue in its lines grows worse; where it's just inside the tank, it doesn't. The water in it does damage of its own: the high-pressure pump and the injectors depend on diesel to lubricate them, and water gives them nothing. ## Why is AdBlue in a diesel commonly the bigger problem? Put petrol in a diesel at the another forecourt nearby and you have a problem of thin fuel. Mixed into your diesel and left still, it's harmless for now; using your motor does the damage. The trouble with AdBlue in a diesel is a completely unsuitable substance. It can't just be run through, since it doesn't burn. Deposits and corrosion remain after the next tankful, and AdBlue separates again out of the diesel, so thinning it can't help. Hence the flush counts so much, and turning your key "to see" costs more here than nearly any other mistake — in Clonoe or the heart of Mountjoy equally. The same good news holds as with petrol. Emptying a tank is the easiest job on any fuel system, and without running, the AdBlue stays in it — anywhere in County Tyrone the car has stopped. ## AdBlue in a diesel tank around Mountjoy: how it ends up there Nobody means to do it. The AdBlue filler on plenty of vehicles waits right next to the diesel filler, sometimes under the same flap, and the two caps can look alike in poor light. A bottle picked up while heading home and tipped in at home, rather than at the filling station, is the usual route. Usually, it happens in one of a couple of familiar ways. Midway through the drop-off, the dashboard warns, and outside the local primary school the refill is rushed. Near Chalet Road, someone pours a bottle in on that drive after work. Or the car is topped up in the car park outside the pub in the village, in poor light, by somebody who has never opened that flap before. The least familiar vehicles see it most — hire cars, brand-new cars, company cars, and the spare car of a family with one of each fuels. An identical mistake, same first step — keep it off — wherever you are in Mountjoy or the rest of County Tyrone. ## Already started the motor with AdBlue in the diesel tank around Mountjoy? If so, the AdBlue is no longer inside that tank. It's been sucked through the fuel filter and the lines, and if your motor ran for any time, it has got to the high-pressure pump and the fuel injectors. You may notice the motor running unevenly, smoking, losing power, showing warning lights or cutting out, maybe on the way back from the green space at the edge of the village or halfway across Mountjoy. Stop as soon as it is safe, switch off, and don't restart the car to check. With each start, more of it is pulled through. Leave the M77, over 50 miles from Mountjoy, at the first junction and park safely, rather than driving on. Mileage matters: each mile carries the AdBlue further in, so heading for Armagh, under 15 miles away, makes a much larger job than crossing Mountjoy to the car park by the centre. Roughly how far it had come is worth telling us. Wherever your car came to a halt is where all of it gets done, even with more to clean out after your engine has been run. If it's noticed quickly, lasting damage is very rare. ## Clearing AdBlue in a diesel in Mountjoy: what it takes A road beside a street just off the centre, a driveway, a layby or a filling station: wherever the vehicle has stopped in Mountjoy, our engineers travel to it. What was put in, roughly how much, plus whether the engine has been run: our technicians check first, because those decide the work. Then that tank is drained where your car stands, and so the polluted fuel and the AdBlue come out together. The fuel system is flushed thoroughly, which matters more with AdBlue than with petrol, since what it leaves behind doesn't rinse out on its own. The filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and your car is tested. Engine not run? In that case expect roughly half an hour on site for most jobs. Our equipment is explosion-proof, and so a live filling station is no problem, and it is hushed enough for a residential street late at night. New diesel goes in to bleed your system, and that's the last step. Firing it up comes next, and then you drive off from where your car is parked, outside the nearest station or on a driveway in Mountjoy. The check before our technicians go is that it runs smoothly on new diesel. No workshop is needed at any point, with the whole job done on the spot. Insurers ask for a VAT invoice and an engineer report, and both come at the end. ## About Mountjoy, briefly Mountjoy is a small locality in County Tyrone, situated inland near the shores of Lough Neagh. Mountjoy sits at a low elevation of around 12 metres, close to the nearby settlements of Brockagh and Washing Bay. Mountjoy is characterized by its predominantly detached housing stock, reflecting its rural setting. Mountjoy is located near the city of Armagh, which is approximately 14 miles away. ## AdBlue drains across County Tyrone, Mountjoy included AdBlue jobs in Mountjoy are passed to vans that cover the towns around it — Brockagh, Washing Bay as well as Acton — and much of County Tyrone further out, throughout BT postcodes. Phone and check instead of guessing when you are by a border, or anywhere awkward to pin down. No moving is needed. In Mountjoy, a small village, a van that comes to you works: the vehicle is emptied on the spot, whether on a driveway, a side street, a parking area or a forecourt. ## Mountjoy: what AdBlue in a diesel tank costs to fix Since each jobs vary, a flat figure would not be fair. The cost moves first with how long, if at all, the engine has been running, and next with the quantity of AdBlue that got in. After that it depends on where the car is and whether our van can reach it safely, which is easier on an open drive than in a tight gap behind the far end of the built-up part. For that in mind, each enquiry from Mountjoy begins with the identical trio — which fluid was put in, how much, if the engine ran — before a figure. Once they are answered, a range turns into one firm figure. Our price is quoted on the call, before anyone sets off; payment happens on the day, by card or over the phone, and nothing upfront. Plenty of insurance policies include misfuelling cover, so it is worth checking yours whilst we're on the way. ## Mountjoy: still alongside your car? Then the most useful thing you can do is nothing to the vehicle. Keys out, engine off, ignition off. Phone 0333 366 0103: AdBlue, the amount, and whether the engine ran are everything our technicians ask. Petrol in Diesel handles the rest across County Tyrone, Mountjoy too.