--- title: Ty-isaf: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/ty-isaf-carmarthenshire/ location: Ty-isaf county: Carmarthenshire latitude: 51.672170 longitude: -4.152960 service: AdBlue in a Diesel Tank updated: 2026-10-14 --- # Ty-isaf: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? AdBlue already in the diesel tank? In that case put this page aside a moment, leave the ignition and engine off, then phone 0333 366 0103. In Ty-isaf, finding it before your motor turns normally leaves a drain and a full flush where it stands. Here before the event? In that case the rest covers how it comes about and what to stop it happening at all. ## AdBlue in a diesel motor: two tanks, two fillers Plenty of newer diesels on the roads around Ty-isaf and Pen-y-fan carry two liquids, not one. Diesel goes to the motor. AdBlue goes to your exhaust, where it is sprayed into the gas to clean it, and it lives in a tank of its own. Each tank has its own filler. Plenty of vehicles have a single flap for the two, while others put the AdBlue filler to your boot or under the bonnet. Diesel gets filled on each forecourt call-out, week in, week out. Someone who has to stop and work out where it goes usually fills the AdBlue side, from a bottle, and far less often. The mistake lives in that gap. ## How AdBlue in your diesel tank happens around Ty-isaf Three things tend to line up, and carelessness is rarely one of them. First, the warning. Low AdBlue brings a warning from the car, and letting it run dry means limp mode — so a rushed top-up, maybe before work off Trinity Road, perhaps outside The Carwyn James on the way home that evening. The old car's filler is where your hand goes — but a hire car, a new motor or a company car keeps the fillers somewhere else. That's a second factor: a new motor. Third, the bottle goes in: diesel filler or AdBlue filler, it slides in just as easily, and after the tip starts, no part halts it. It's a few seconds, whether out in Bigyn or bang in the centre of Ty-isaf. ## How to tell the AdBlue filler from the diesel one A few seconds is all the checks take — so check them before you pour anything, on a drive in Seaside or a forecourt in Ty-isaf. - Position misleads; the cap doesn't. AdBlue caps tend to be blue or carry the word "AdBlue" — diesel ones normally don't. - Plenty of vehicles give AdBlue the smaller neck of the two. - Lift the filler flap and look for a label — many vehicles show which goes in which inlet just there. - The handbook. If your filler is not by the diesel cap, it's in the boot or under the bonnet, and the handbook says which. - The person who drove the vehicle last. On a hire or company car collected from somewhere like the car park at Llanelli, ask before you leave, not when the light comes on. ## Keeping AdBlue out of your diesel tank when you top up A routine for the day the light comes on, wherever across Carmarthenshire that is. - Park then switch off. Not on a slope, not with the motor running, and not in a rush on the side of Pen Y Morfa. - Find the AdBlue filler, check the cap, and speak the word "AdBlue" aloud as unscrewing it. It seems silly. It does the trick. - Both behind one flap? Then make sure the cap on the diesel side is still closed ahead of lifting the bottle. - Pour slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty. - Close the cap, then check once more — making sure the diesel cap stayed closed the whole time. After that, start the vehicle. If at stage two or three you find you have already poured into the diesel side, stop there. Step five stays off limits. ## Ty-isaf: already put AdBlue in the diesel tank? Brief order, then. Top of that: the motor remains unstarted. On many diesels the ignition alone runs the fuel pump, and so do not switch it on. Don't top up with diesel to dilute it: AdBlue doesn't mix with diesel, it sinks to the bottom of that tank, where your fuel is pulled from. Ask the staff to help push the car clear of the petrol pump if you're at a forecourt — the Asda, the Tesco or anywhere else. Leave it where it is if you are on your own drive around Ty-isaf. Stop as soon as it is safe then switch off, if your engine has already run. Ty-isaf sits under 5 miles from the M4; there, take the first exit. Roughly how far did it go? Hopping across Ty-isaf is less a job than a trip of under 10 miles towards Swansea, so tell us. ## Our arrival around Ty-isaf, and what happens next We come to the vehicle wherever it has stopped, whether that's outside the local primary school, close to Trinity Welsh Presbyterian Church or on your own drive. Both the work and the quote rest on three answers — what fluid, which amount, and if it's run — so we ask. No one sets off until you have had the price by phone. The system is then flushed thoroughly, once the tank is drained. With AdBlue that counts more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own. Filter flushed or, where needed, replaced; fresh diesel in; and then a check of your vehicle. Before leaving, we fire it up and make sure that it's running correctly. Using pumps safe on a busy forecourt and quiet enough to use outside a house at night, most jobs in which the motor has not run need roughly half an hour after our technicians arrive. Your insurer usually wants an engineer's report and the VAT invoice, and both are yours at the end. Payment comes on the day, with no money upfront. While we travel, have a look at your insurance documents; many carry cover for misfuelling. ## About Ty-isaf itself Ty-isaf is a suburban area located on the coast of Carmarthenshire, with its elevation at around 6 metres above sea level. Ty-isaf sits near the cities of Swansea and Llanelli, and is close to nearby places such as Bigyn, Wern, and Morfa. Ty-isaf has a population of approximately 6393 people, and its housing stock is predominantly made up of terraced properties. ## AdBlue drains around Ty-isaf, and Carmarthenshire beyond Over SA postcodes, the teams covering Ty-isaf — a residential suburb — work the nearby places too, Morfa and Wern among them. Give a postcode beginning SA15 2, and our van arrives quickest. Your car does not need to move. The drain happens on the spot, whether a drive, a street by St Barnabas Community Hall, or a lay-by on the way to Penyfan Quarry. If you're close to a border, or somewhere hard to explain like the back of Llyfrgell Tregoning, ring and ask instead of assuming. ## In short, for Ty-isaf people First, the cap; then, the tip. Petrol in Diesel empties it where it stands, anywhere in Carmarthenshire, if AdBlue has gone in your diesel tank anyway — and so leave it off then phone 0333 366 0103.