--- title: Croesywaun: AdBlue in a Diesel Tank, What Next canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/croesywaun-gwynedd/ location: Croesywaun county: Gwynedd latitude: 53.112230 longitude: -4.205130 service: AdBlue in a Diesel Tank updated: 2026-10-12 --- # AdBlue in the Diesel Tank in Croesywaun: What Now? Has the motor turned over since the AdBlue went in? That one point decides almost everything else from here. Wherever your car is — Betws Garmon, Croesywaun — never run a motor that hasn't run yet. Leave the motor and your ignition off then phone 0333 366 0103; it's generally a drain and a thorough flush, done where the car is in Croesywaun. Where the motor has run, pull in safely straight away, then turn it off. A bigger job, yes, but the same opening step. Find the situation below that matches yours, wherever across Gwynedd it happened. ## At the petrol pump around Croesywaun: AdBlue in a diesel Just now, bottle yet in hand, you realise that the cap you took off was the wrong one, right at the pump. Perhaps you are at the Shell, maybe at the Essar, maybe somewhere else in Croesywaun. Meaning? Finding out here is as good as it can be. Still inside your tank, and no fuel pulled onwards: that's where the AdBlue is. Your move: keep out of the car, however much the pump wants clearing. Get the staff to help rolling it into a bay, hold on to the receipt, then ring us right there. If it can't be moved, it can be cleared at the pump: the equipment is explosion-proof and fine on a busy forecourt. ## Croesywaun, at home: AdBlue in the diesel tank Days had gone by with the dash light on. Only at the recycling bin, the empty bottle in your hand, did you look back at the cap you'd used on the drive. Drives near Llys yr Waun get it as much as anywhere. Meaning? Provided the vehicle has not been driven since, it is second to the forecourt case. At the bottom of your tank is where AdBlue stays, because it won't mix with diesel — and a night passing changes nothing of the difference. Next: stop an early drive by putting the keys indoors, then ring us. Our technicians drain the vehicle on your drive, whether that's in Croesywaun or out in Waunfawr. Late-night empties outside a house are fine: the pumps are quiet. ## Croesywaun: drove off with AdBlue in a diesel? Lumpy running, smoke, falling power or a lit dashboard started a short way after the fill. Maybe it was on A4085, perhaps on the way out towards Bangor, under 10 miles away. The point: the system has drawn AdBlue through by now. The high-pressure pump and every injector see it as well on a bigger trip, after the filter and pipework have had it. It travels further with each mile covered and each restart. Next: find a safe spot, pull in, and turn the motor off. Croesywaun sits under 50 miles from the Moreton Spur; on it, pull off at the next junction instead of pressing on for the services. Restarting it to test achieves nothing — AdBlue doesn't clear on its own. Phone us and say how far you travelled. ## AdBlue in the wrong tank of a hire, lease or company car It is a vehicle you have had for a week. On your own vehicle, AdBlue is missing or elsewhere. On this one, the cap is right by the diesel inlet — a surprise to you. Wherever you are around Gwynedd, any motorist could be caught. The point: just as above, divided by if it ran, only with one added step. Many hire and company agreements need the owner's sign-off for repairs. Your move: rental firm or fleet manager to begin with, us second, because sorting it early saves time. If you're stranded in the car park outside Llanfairpwll, or by Former ROC Nuclear Monitoring Post 1959-69, while you wait for an answer, leave your car off. ## Unsure about AdBlue in the diesel tank in Croesywaun? Truthfully, the only answer might be that you think it did. The bottle is lighter than it should be, there's a faint smell of ammonia about your filler, and you can't remember which cap you took off. A rushed top-up by the gates of the local primary school, or a visit to a friend in Tan-y-coed: both fits. What it means: a little spilled about your filler does no damage to the engine. In your diesel tank, by contrast, AdBlue damages it. Any AdBlue in the tank will be sucked in by firing up the car, and the start would not settle which it is in any case. Your move: act as though it did, and don't start the engine. Call us and explain what you saw; we'd rather check a tank that turns out clean than drain one that has already been run. ## Croesywaun: what each AdBlue drain has in common Each case has the same opening to the work. We come to the car, whether it's at a forecourt, a drive, the car park outside Snowdonia Parc or a side street close to St Garmon, and ask three things: what got in, roughly how much, and if your engine has been run. Those replies determine this work, and you hear the quote by phone, before anyone sets off. Emptying that tank comes first, followed by a full flush — more important with urea than with petrol, because crystals and corrosion will not go on their own, however long it sits. Then is the filter — flushed, or replaced when needed — then clean diesel, and a test of your car. Never started? In that case roughly half an hour on site covers most jobs. Finally, our technicians fire it up. We check it runs properly on clean diesel before leaving. Permanent damage is very uncommon if it is noticed quickly, and the whole job is done where the car is. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Check your insurance while we're en route: cover for misfuelling comes included in plenty of policies. ## About Croesywaun, for a moment Croesywaun is a locality situated on the banks of a river in Gwynedd, with Waunfawr, Groeslon, and Ceunant nearby. Croesywaun has a population of around 928 people and is characterised by detached housing. Croesywaun sits at an elevation of 162 metres, approximately 8.6 miles from Bangor. Croesywaun is located in a scenic area, with the city of Bangor and the surrounding countryside providing a range of amenities and services. ## AdBlue drains across Gwynedd, Croesywaun included Croesywaun is a small village, and the same vans that cover it work the towns around it too, Groeslon and Ceunant among them, across the LL postcode area. Your location is clearest from a postcode that starts LL55 4. No moving is required, be it parked in the centre of Croesywaun or in a layby en route to Y Bicell, so leave it put. Our van drains it in place. If you're somewhere hard to explain, close to Hut Circles (Cae Hen) or close to a boundary, ring and ask rather than guessing. ## The one-line version Motor not started: ring, leaving it alone. Already run: stop, switch off then ring. Either way, Petrol in Diesel takes it from there around Croesywaun and anywhere across Gwynedd on 0333 366 0103.