--- title: Explained: AdBlue in a Diesel Tank Underdale canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/underdale-shropshire/ location: Underdale county: Shropshire latitude: 52.716920 longitude: -2.733120 service: AdBlue in a Diesel Tank updated: 2026-10-21 --- # Avoiding AdBlue in a Diesel Tank in Underdale: Why It Happens AdBlue already in the diesel tank? In that case set this page down a moment, leave the ignition and engine off, then phone 0333 366 0103. Around Underdale, finding it before the motor turns normally means a drain and a thorough flush on the spot. If you are reading before it has happened, the rest of this page is about why it takes place and how to make sure it does not. ## AdBlue in a diesel vehicle, and its separate tank Plenty of modern diesels around Castlefields, like those in Underdale, run on two liquids; the engine takes just the diesel. Stored in a tank of its own, AdBlue is fed into the exhaust stream to clean it. Each tank has its own filler. Many of motors have a single flap for both, whereas others put the AdBlue filler to the boot or under the bonnet. Topping up your diesel side at the petrol pump happens constantly. The AdBlue side is topped up far less often, normally from a bottle, and usually by a person who has to stop and think where it goes. It is in that gap that the error happens. ## How does AdBlue in the diesel tank take place in Underdale? It's hardly ever carelessness. Three things tend to line up. To start with, the warning. Low AdBlue brings a message from the vehicle, and running dry means limp mode — hence a rushed top-up, perhaps before work off Curia Close, perhaps outside The Monkmoor on the way home that evening. New-to-you cars are second, too. Rentals, new motors and company vehicles place their fillers differently, and habit reaches for the cap used on the old one. Lastly, the spout fits: a diesel filler or AdBlue filler, it slides in as easily, and after the tip begins, nothing stops it. Spring Gdns or the heart of Underdale: it is the same few seconds in both. ## The AdBlue filler and your diesel filler: telling them apart Before you tip anything, whether on a drive in Cherry Orchard or a forecourt in Underdale, check these. They take a couple of seconds. - Colour and marking: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap usually does not. Go by the cap, not where it sits. - Plenty of motors fit AdBlue the smaller neck of the two. - A label inside the fuel flap often shows which fuel goes where, on plenty of vehicles. Check for it. - In the boot or under the bonnet: that's where the filler sits if it is not by your diesel cap, and the handbook says which. - Collecting a hire or company car, perhaps at the car park at Shrewsbury? Check with the person who drove the vehicle last before you set off, not once the light goes on. ## Topping up AdBlue without it reaching your diesel tank A routine for the day the light comes on, wherever in Shropshire that is. - Stop on level, engine off, with time to spare — not hurried on the side of Underdale Court. - Locate the AdBlue filler, read the cap, and say the name "AdBlue" aloud while you unscrew it. It seems daft. It works. - The diesel cap remains on. When the two share a flap, confirm it's closed before the bottle comes up. - Pour slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Only then, start your car: close the cap, check again, and make sure the diesel cap was never opened. If at step two or three you find you have already poured into the diesel side, stop there. Never go on to stage five. ## Put AdBlue in the diesel tank around Underdale already? What follows is a short order of things, beginning with not starting your motor. Keep your ignition off as well, since on many diesels it alone starts the fuel pump. Do not top up with diesel to thin 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 are at a forecourt — the Morrisons, the Asda or anywhere else. Leave it where it is if you're on your own drive in Underdale. If the engine has already run, stop as soon as it is safe then switch off. Underdale lies under 10 miles from the M54; on it, use the next exit. Mileage matters — a short hop across Underdale is a smaller job than heading under 50 miles to Wrexham — so say about how far it went. ## Underdale: what takes place when we get there Anywhere the car has stopped, whether outside The Martin Wilson School, beside St Peter or at home, the van comes to it. What liquid got in, the quantity, and if it ran: we ask because the replies set both work and price. You hear that price on the phone, before anybody heads out. The system is then cleaned thoroughly, once the tank is cleared. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it doesn't wash out on its own. Filter cleaned or, if needed, replaced; clean diesel in; and then a test of your vehicle. Before we leave, we start it and make sure that it is running correctly. If the motor has not run, most jobs take about half an hour once we're there, using pumps that are safe on a working forecourt and quiet enough to use outside a house at night. The insurer usually wants an engineer's report and the VAT invoice, and you get both once the job is done. Payment is on the day, with no money upfront. Plenty of insurance policies include misfuelling cover, and so it's worth checking yours whilst we're on the way. ## About Underdale Underdale is a suburban area in Shropshire, situated on the riverside at an elevation of around 55 metres. Underdale lies near the suburbs of Shrewsbury, close to areas like Spring Gdns and Monkmoor, and is characterized by its predominantly semi-detached housing stock. Underdale is located approximately 25 miles from Wrexham and about 139 miles northwest of London. ## Underdale and Shropshire: AdBlue drains across the area Being a residential suburb, Underdale has the same vans as surrounding areas — Spring Gardens, Monkmoor — right across SY postcodes and the surrounding area around them. Quote a postcode beginning SY2 5, and the van gets there quickest. Your car doesn't need to move. Our technicians drain it where it is — a side street near Monkmoor Recreation Ground, a lay-by on the way to Underdale Community Woodland, a driveway. If you're near a boundary, or somewhere hard to explain like the back of Shrewsbury Triratna Buddhist Centre, ring and ask instead of guessing. ## In short, for Underdale motorists Read the cap before you tip. Petrol in Diesel empties it on the spot, anywhere in Shropshire, if AdBlue has gone in the diesel tank all the same — and so leave the vehicle off then call 0333 366 0103.