--- title: Pontcynon: AdBlue in a Diesel Tank? Don't Start canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/pontcynon-rhondda-cynon-taf/ location: Pontcynon county: Rhondda Cynon Taf latitude: 51.653510 longitude: -3.335630 service: AdBlue in a Diesel Tank updated: 2026-10-06 --- # Pontcynon: AdBlue in the Diesel Tank? Leave It Off Engine off, ignition off: that's how you start if AdBlue has gone into the diesel tank. Urea dissolved in water is all AdBlue is. As it is water-based, it won't ignite and never combines with diesel; trouble only comes when the pump starts drawing it. In Pontcynon, AdBlue in a diesel tank caught before the motor runs normally means a drain and a thorough flush, right where the vehicle is. Before you do anything else, call 0333 366 0103. ## Pontcynon, AdBlue in your diesel tank: what to do straight away Things to do: - Pull your keys out, so no one switches your ignition on. - Hazards on, if moving traffic is anywhere close. - Hold on to the till receipt or the empty bottle, and so you can tell us what went in and roughly how much. - Call us from where you are. A postcode starting CF45 4, or the name of the nearest street, gets the van to you without a search. Don't: - Moving the car just a few yards is no reason to fire up the engine. - Do not switch the ignition on. On plenty of diesels that alone runs the fuel pump. - Adding extra diesel does not work: AdBlue settles out rather than blending. - Never drive it anywhere, not even a short distance down B4275. - Beside the road, don't attempt emptying it yourself. Get the attendants to help you roll your vehicle off the pumps if you're on a forecourt around Pontcynon, whether it's the Texaco or somewhere else. Stopped on your own drive? Then it stays exactly as it is. ## AdBlue in a diesel tank: what it does Not the motor but the exhaust is where AdBlue is meant to go. From a dedicated reservoir it is fed straight to the exhaust, treating what your engine lets out. No part in an injection pump is designed for this liquid — and no part of it was intended to travel through one. Poured in with the diesel, it stays separate rather than mixing — entirely unlike fuel. It is heavier than diesel, so it sinks and gathers at the bottom of your tank, which is where the pickup sucks fuel from. When your pump runs, the AdBlue is first to go through. Before then it sits beneath the diesel, which is why a vehicle filled in Tyntetown last night and never started remains the straightforward case, provided nobody touches your key. From there it does two kinds of harm. As its water goes, the urea left behind crystallises, and the crystals block filters and settle in fine passages. And it's corrosive to some of the metals a fuel system is made from, and so it keeps labouring on the parts it reaches for as long as it remains there. If the AdBlue is in the lines, leaving it overnight around Pontcynon leaves it worse. In that tank alone, waiting does nothing. And there's the water: it brings no lubrication to the components that rely on it most — the injection pump and every injector. ## Why AdBlue in a diesel is regularly more serious than petrol Put petrol in a diesel at the Gulf Treharris Service Station and you have an issue of thin fuel. Damage just comes from running on it. Blended into the diesel and sitting in your tank, it causes none. With AdBlue in a diesel, the fluid as such is simply the wrong one. It can't simply be run through, since it doesn't burn. It doesn't stay mixed, and so it can't be weakened. And crystals and corrosion don't wash out with the next tank of fuel. That's why the flush counts more with AdBlue than with petrol, and why starting your engine "to see" costs more here than nearly anywhere else, whether the vehicle is in Carnetown or the middle of Pontcynon. The good news is the same as with petrol. Wherever around Rhondda Cynon Taf the vehicle has stopped, an unrun motor leaves the AdBlue still in the reservoir: the simplest part of any fuel system to empty. ## Pontcynon: how AdBlue ends up in a diesel tank Nobody means to do it. The AdBlue filler on plenty of cars sits right next to the diesel filler, at times under the same flap, and the two caps can look alike in poor light. Most of the time it happens with a bottle bought on the way home and poured in on the driveway, not at the pump. The ways it takes place are few and familiar. A warning light comes on during the school run, and the top-up takes place in a hurry outside the local primary school. In the evening, a bottle goes in on a drive close to Abercynon Road. One more pattern: dim light, the car park by Thorn Hotel, and a driver opening that flap for the first time. The least familiar cars see it most — rentals, brand-new cars, fleet cars, and the spare vehicle of a home with both fuels. An identical mistake, same first response — leave it switched off — wherever you happen to be around Pontcynon or the remainder of Rhondda Cynon Taf. ## Started your engine with AdBlue in your diesel tank around Pontcynon? In that case, the AdBlue is no longer in the tank. Via the fuel filter, through the pipework, and — given any running time — into the high-pressure pump and each injector: that's how far it has gone. Watch for lumpy running, smoke, falling power, lights on your dash, or a cut-out — coming back from Parc Abercynon, say, or midway across Pontcynon. Stop as soon as it is safe, switch off, and don't restart it to check. Each start pulls more of it through. If you were on the M4, under 10 miles from Pontcynon, come off at the next junction and stop somewhere safe instead of pressing on. Hopping across Pontcynon to the car park by English Congregational Church is one thing; heading for Cardiff, under 15 miles away, is another, since each mile pushes the AdBlue further in. So mileage matters. Roughly how far it had come is worth telling us. There is more to rinse out once the engine has run, and our engineers do all of it where the vehicle has ended up. Lasting damage is very unusual if it's caught soon. ## What draining AdBlue from a diesel involves around Pontcynon A road by The Church of Christ Evangelical Baptist Church, a driveway, a lay-by or a filling station: anywhere your car has come to rest in Pontcynon, our engineers come to it. What got in, about the quantity, plus if the engine has been run: our engineers check first, because those shape the job. Then that tank is drained where the car sits, and so the polluted fuel and the AdBlue come out together. With AdBlue, far more than with petrol, flushing matters: the fuel system is cleaned all the way through because residue won't wash away by itself. Clean diesel goes in once the filter is cleaned — or swapped, if it needs to be — and then the vehicle is tested. Engine not run? In that case count on roughly half an hour once we are there for most jobs. Our pumping gear is explosion-proof, so a busy forecourt is no fault, and it is hushed enough for a residential street after dark. Bleeding the system with new diesel comes last. At that point our engineers start the car and you head off, whether from a parking bay by Quakers Yard or a drive around Pontcynon. Before we go, our engineers make sure it is running smoothly with new diesel in. Our technicians do it all wherever the vehicle has ended up, and it never needs to go to a workshop. Afterwards, there is the paperwork for the insurer: a VAT invoice plus a written report from the engineer. ## About Pontcynon and where it is Pontcynon is a suburban area situated on the banks of the River Cynon in Rhondda Cynon Taf, with nearby settlements including Ynysboeth and Abercynon. Pontcynon has a mix of housing types, but is predominantly characterised by terraced homes. Pontcynon is located close to the town of Abercynon and the village of Bryntirion, and is approximately 13 miles north of Cardiff. Pontcynon sits at an elevation of around 93 metres above sea level, in a valley setting. ## AdBlue drains in Pontcynon and across Rhondda Cynon Taf Throughout the CF postcode area, the vans answering AdBlue jobs in Pontcynon reach much of Rhondda Cynon Taf as well, Ynysboeth, Abercynon and Bryntirion included. Ring and check rather than guess if you are close to a border, or anywhere awkward to pin down. No towing is needed. In Pontcynon, a residential suburb, a van that comes to you works: your vehicle is drained where it stands, whether in a drive, a side street, a car park or a filling station. ## What AdBlue in a diesel tank costs to put right in Pontcynon Not one flat price could be fair, since every job differs. What shifts the cost is, firstly, whether the engine has run and for how long; then how much AdBlue got in; and then where your car is and whether our van can get to it safely, which is easier on an open drive than in a tight spot behind Ynysybwl Cenotaph. Ahead of a figure, not after, every call from Pontcynon opens with three checks: the fuel, the amount, plus if it ran. Given those replies, a range shrinks to one fixed figure. Priced by phone before the engineer heads out, the job is paid for that day — card or phone, nothing in advance. As the van is travelling, dig out your insurance: many cover misfuelling. ## Pontcynon: still beside your car? In that case, touch nothing — that is the most helpful move available. Keys out, motor off, ignition off. Ring 0333 366 0103: AdBlue, roughly how much, and if the engine ran is everything we need. Petrol in Diesel handles the remainder across Rhondda Cynon Taf, Pontcynon included.