--- title: Explained: AdBlue in a Diesel Tank Penrhyn-coch canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/penrhyn-coch-ceredigion/ location: Penrhyn-coch county: Ceredigion latitude: 52.437610 longitude: -3.998890 service: AdBlue in a Diesel Tank updated: 2026-10-04 --- # AdBlue in a Diesel Tank in Penrhyn-coch: Why It Happens and How to Stop It If AdBlue is already in your diesel tank, stop reading for a moment: leave the engine and your ignition off then phone 0333 366 0103. Around Penrhyn-coch, finding it before your motor turns usually leaves a drain and a thorough flush on the spot. The rest of this page explains why it takes place and how to make sure it does not — useful if you're reading before it has happened. ## Two fillers, two tanks: AdBlue in a diesel car No single liquid but two: that is what many newer diesels near Penrhyn-coch and Bow Street run, with diesel for the engine. Kept in a tank of its own, AdBlue is fed into the exhaust stream to clean it. There's a filler on every tank. Some motors keep the AdBlue filler in the boot or under the bonnet; plenty more place both together behind one flap. Topping up the diesel side at the pump happens constantly. Far less commonly, the AdBlue side is filled — normally from a bottle, by a person working out where it goes. It's in the gap that the mistake lives. ## How AdBlue in the diesel tank takes place in Penrhyn-coch Seldom is it carelessness: normally three things coincide. Hurry comes from the warning. The car warns you as AdBlue runs low, and an empty tank sends the vehicle into limp mode — so the top-up happens in a rush, before work on a driveway off Maesheulog, or heading home in the car park outside the pub in the village. Unfamiliar motors come next, as well. Rentals, new motors and company cars put their fillers in new places, and the hand goes for the cap it used on the old one. No part halts the tip after it has started, because a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. Garth or the heart of Penrhyn-coch: it is the same few seconds either way. ## Telling the AdBlue filler from the diesel filler Before you pour anything, whether on a driveway in Pen-y-garn or a forecourt around Penrhyn-coch, check these. They take a couple of seconds. - The cap. The AdBlue cap is commonly blue, or marked "AdBlue". The diesel cap normally is not. Read it rather than going by where it sits. - The size. On plenty of motors the AdBlue filler neck is the smaller of the two. - The flap. Look inside the fuel flap for a label. Many cars say there which fuel goes where. - Cannot find it beside your diesel filler? Then check beneath the bonnet or inside the boot — the handbook says where. - The person who drove it last. On a hire or company car picked up from somewhere like the car park outside Bow Street, ask before you leave, not when the light comes on. ## Topping up AdBlue without it reaching the diesel tank Wherever in Ceredigion the light comes on, here is a routine for the day. - Not in a rush on the side of Nant Seilo, not on a slope, not with your motor running: park then switch off properly. - Daft as it sounds, saying "AdBlue" out loud while you unscrew the cap works — after you've located your filler and read it. - The two under one flap? Then make sure the lid on your diesel filler stays shut before lifting the bottle. - Slowly does it, through the bottle's own spout, till it's full or the bottle runs out. - Only then, start the car: close the cap, check once more, and make sure the diesel cap was never opened. If at step two or three you find you have already poured into your diesel side, stop there. Never go on to step five. ## Already put AdBlue in the diesel tank around Penrhyn-coch? Brief order, then. Top of that: the engine remains off. The fuel pump runs on many diesels the moment your ignition goes on — so keep it off. AdBlue doesn't mix with diesel — it sinks to the bottom of your tank, where your fuel is drawn from — so do not top up with diesel to thin it. If you are at a forecourt, whether it is the BP or the another forecourt nearby, ask the staff to help push your car away from the petrol pump. If you're on your own drive around Penrhyn-coch, leave the car where it sits. Where your motor has been run by now, stop somewhere safe then turn the vehicle off. Penrhyn-coch sits under 50 miles from the M4; there, take the first junction. Tell us about how far it went: a run towards Bangor, over 50 miles away, is a bigger job than a short hop across Penrhyn-coch. ## When our technicians arrive around Penrhyn-coch, what occurs? Our van comes to the vehicle anywhere it stopped — your own drive, beside Penrhyn-coch War Memorial, or by the local primary school. Both the work and our price depend on three replies — which fluid, what amount, and if it's run — so we ask. You get that price by phone, before anyone sets off. Emptying your tank comes next, followed by a thorough flush of your system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own — which is why that counts more here than with petrol. After the fuel filter is flushed — or renewed, if required — clean diesel goes in, and then the car is tested. The motor is fired up next and checked to confirm it runs correctly, all before our technicians leave. Most jobs are finished in roughly half an hour after we get there, as long as the motor has not run — and the pumps we use are fine on a busy forecourt and quiet at night beside a house. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. It's worth looking at your insurance as the van travels to you: misfuelling cover comes with plenty of policies. ## About Penrhyn-coch and where it is Penrhyn-coch is a village in Ceredigion, situated on the banks of a river at an elevation of 48 metres. Penrhyn-coch lies near the settlements of Garth and Plas Gogerddan, and is part of a wider area that includes Cefn Llwyd. Penrhyn-coch has a population of around 938 people, predominantly living in semi-detached housing. Penrhyn-coch is located approximately 176.8 miles from London and 54.9 miles from Bangor. ## AdBlue drains across Ceredigion, Penrhyn-coch included Penrhyn-coch is a village, and our vans that cover it also work the places around it, Plas Gogerddan and Cefn Llwyd among them, across the SY postcode area. Give a postcode beginning SY23 3, and the van arrives fastest. No need to shift the vehicle. A drive, a lay-by on the way to Allt Dderw, a side street close to Neuadd yr Eglwys, Penrhyn-coch: our engineers drain the vehicle where it is. Ring and ask instead of assuming if you're close to a border, or somewhere hard to explain, like the back of Eglwys Sant Ioan. ## Penrhyn-coch drivers: the short version Read the cap before you tip. AdBlue in the diesel tank regardless? Leave the vehicle off and ring 0333 366 0103; Petrol in Diesel drains it where it stands, across Ceredigion.