--- title: AdBlue in a Diesel Tank Pengam: Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/pengam-newport/ location: Pengam county: Newport latitude: 51.513230 longitude: -3.062080 service: AdBlue in a Diesel Tank updated: 2026-10-11 --- # Pengam: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? If AdBlue is already in your diesel tank, stop reading for a moment: leave your motor and your ignition off and call 0333 366 0103. Around Pengam, catching it before the motor turns usually leaves a drain and a full flush on the spot. If you're 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: two tanks, two fillers Not one liquid but two: that is what many newer diesels around Pengam and Marshfield carry, with diesel feeding your motor. Kept in a tank of its own, AdBlue is fed into the exhaust stream to clean it. Each tank has its own filler. Other vehicles put the AdBlue filler in the boot or under the bonnet; a lot of others place the two side by side under one flap. Filling your diesel side at the pump happens constantly. Far less commonly, the AdBlue side is filled — mostly from a bottle, by someone working out where it goes. It's in that gap that the slip lives. ## How does AdBlue in your diesel tank take place in Pengam? It is hardly ever carelessness. Three things tend to line up. To start with, the warning. Low AdBlue triggers a message from the vehicle, and letting it run dry leads to limp mode — hence a rushed top-up, maybe before work off Wentloog Road, perhaps outside the pub in the village on the way home after work. Next, your hand goes for the cap it would have used on the old motor — because a hire car, a new vehicle or a company car puts the fillers where your last one didn't. Third, the bottle fits: diesel filler or AdBlue filler, it goes in as readily, and once the tip begins, nothing halts it. It takes seconds, be it in Peterstone Wentlooge or bang in the heart of Pengam. ## The AdBlue filler and your diesel filler: telling them apart Be it a Pengam forecourt or a driveway out in Newton, take a few seconds on these before any is poured in. - Colour and marking: an AdBlue cap is commonly blue, or says "AdBlue", where a diesel cap normally does not. Go by the cap, not where it sits. - On many cars, the size tells: AdBlue has the smaller filler neck. - A label inside the fuel flap often says which fuel goes where, on plenty of cars. Look for it. - The handbook. If your filler is not by your diesel cap, it is in the boot or under the bonnet, and the handbook says which. - The previous driver knows. Ask as you pick up a hire car or company car — from Pye Corner's car park, perhaps — not once the warning comes on. ## How to top up without AdBlue in the diesel tank A routine for the day the light comes on, wherever around Newport that is. - Switch off after you park — flat ground, engine off, and never rushed by Heol Las on the verge. - Say "AdBlue" out loud as you unscrew the cap, after you find the AdBlue filler and read it. Daft, perhaps, but it works. - Both behind one flap? So confirm the lid on your diesel filler stays shut ahead of lifting the bottle. - Slowly is best, through the bottle's own spout, until it is full or the bottle is empty. - Before starting your car, close the cap and look again that the diesel cap never came off. If at stage two or three you find you have already poured into your diesel side, stop there. Don't go on to stage five. ## Pengam: already put AdBlue in the diesel tank? Do not start your engine: that is how the short order of things starts. On many diesels your ignition alone runs the fuel pump, so don't switch the car on. Thinning it with more diesel fails, since AdBlue sinks to the base instead of mixing — and that's where the fuel is drawn from. The attendants at Tesco, Texaco or any forecourt will normally lend a hand to push your car clear if you ask. Your own driveway around Pengam is the place it should stay. If the motor has already run, stop as soon as it is safe then switch off. Pengam sits under 3 miles from the A48(M); there, use the next exit. Roughly how far did it go? Hopping across Pengam is smaller work than a run of under 10 miles to Cardiff, so say. ## Pengam: what takes place when we get there We come to the car wherever it has stopped, whether that is outside the local primary school, near Marshfield Village Hall or on your own drive. The replies settle the work and the price, and so our technicians ask what got in, roughly how much, and if it has run. On the phone call itself, you hear the price — ahead of dispatch. After that: a drain, then a full flush of the whole system. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own. The filter is flushed, or replaced where it needs to be; clean diesel goes in; and the car is tested. The motor is started next and tested to be sure it runs smoothly, all before our technicians leave. With pumps fine on a busy forecourt and quiet enough for use outside a house at night, most jobs where your motor hasn't run need about half an hour once our technicians are there. The insurer will ask for an engineer's report and the VAT invoice, and both are yours at the end. Payment is on the day, with no deposit. It is worth looking at your insurance while we travel to you: misfuelling cover comes with plenty of policies. ## About Pengam and where it is Pengam is a small coastal hamlet in Newport, situated near the mouth of the Severn Estuary at a low elevation of around 6 metres. Pengam lies close to the cities of Cardiff and Newport, and is surrounded by other small communities such as Peterstone Wentlooge and Broadstreet Common. Pengam has a population of approximately 516 people, living in predominantly semi-detached housing. ## AdBlue drains across Newport, Pengam included Pengam is a rural hamlet, and the vans that cover it also work the towns near it, Broadstreet Common and Blacktown among them, across the CF postcode area. Our van gets to you fastest with a postcode starting CF3 2. Moving your car isn't necessary. We drain it where it is — a side street near The Beacon Centre, a lay-by on the way to Peterstone Golf Club, a drive. Tricky to pin down, like the back of St Mary's? By a border? Checking beats assuming, and so phone. ## For Pengam motorists, the short version Tip no AdBlue till you have read the cap. Still AdBlue in your diesel tank? Petrol in Diesel will drain it wherever it stands, anywhere in Newport: keep it off and phone 0333 366 0103.