--- title: Explained: AdBlue in a Diesel Tank Wenvoe canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/wenvoe-the-vale-of-glamorgan/ location: Wenvoe county: The Vale of Glamorgan latitude: 51.447760 longitude: -3.264510 service: AdBlue in a Diesel Tank updated: 2026-10-14 --- # Wenvoe: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? Keep your engine and ignition off then phone 0333 366 0103 now — the rest can wait if AdBlue is already in your diesel tank. Usually, when your motor has not run, it is drained and fully rinsed where the car is around Wenvoe. 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. ## Two fillers, two tanks: AdBlue in a diesel car Plenty of newer diesels on the roads round Wenvoe and Burdonshill carry two liquids, not one. Diesel goes to the engine. AdBlue goes to the exhaust, where it is sprayed into the gas to clean it, and it lives in a tank of its own. There is a filler for each tank. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. The diesel side is filled at the pump all the time. Someone who has to stop and work out where it goes usually tops up the AdBlue side, from a bottle, and much less often. That gap is where the mistake lives. ## Wenvoe: how AdBlue in the diesel tank takes place It's hardly ever carelessness. Three things tend to line up. First, the warning. Low AdBlue triggers a warning from the car, and running dry means limp mode — hence a rushed top-up, maybe before work off Springfield Close, perhaps at The Wenvoe Arms on the way home after work. Then the car is unfamiliar. A hire car, a new vehicle or a company car puts the fillers where your last one didn't, and your hand hits for the cap it would have used on the old one. Nothing halts the tip once it has started, since a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. It's a few seconds, whether out in Wallston or bang in the heart of Wenvoe. ## Which filler is for AdBlue, and which for diesel? Before you tip anything, whether on a drive in Saint Andras or a forecourt around Wenvoe, check these. They take a few seconds. - The cap. The AdBlue cap is frequently blue, or marked "AdBlue". The diesel cap usually isn't. Read it rather than going by position. - Look at the size: the smaller neck is, on plenty of vehicles, the AdBlue one. - The flap. Look inside your fuel flap for a label. Many vehicles say there which fuel goes where. - Cannot see it next to your diesel filler? In that case check below the bonnet or inside the boot — the handbook says where. - Whoever had it before knows. Check as you collect a rental or company car — from Dinas Powys's car park, say — rather than once the warning appears. ## AdBlue top-ups that never reach your diesel tank A routine for the day the light comes on, wherever around The Vale of Glamorgan that is. - Turn off after you park — level ground, motor off, and never in a rush beside Old Market 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 does the trick. - If both sit under one flap, check the diesel cap is still closed before you lift the bottle — then leave it on. - Tip slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Before you start the car, shut the cap and look again that your diesel cap was never opened off. Find at stage two or three that it has already gone into your diesel side? So stop right there. Step five stays out. ## AdBlue in the diesel tank already, in Wenvoe? Don't start the engine: that is how the short order of things begins. Keep the ignition off as well, because on plenty of diesels it alone runs the fuel pump. AdBlue doesn't mix with diesel — it sinks to the bottom of the tank, where your fuel is pulled from — so don't top up with diesel to thin it. Ask the attendants to help roll your car away from the pump if you're at a forecourt — the Tesco, the Texaco or somewhere else. Your own drive in Wenvoe is where it stays. Stop as soon as it is safe and switch off, if your motor has already run. On the M4, under 5 miles from Wenvoe, that means the next exit. A short hop across Wenvoe is a smaller job than a run towards Cardiff, under 5 miles away, so tell us about how far it went. ## Our arrival around Wenvoe, and what occurs next Our technicians come to the car wherever it has stopped, whether that is outside the local primary school, close to Wenvoe Village Hall or on your own driveway. Both the work and the quote depend on three answers — what liquid, which quantity, and if it's run — so our engineers ask. You hear that price on the phone, before anybody heads out. Next: a drain, then a thorough flush of the entire system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own — which is why that counts more with AdBlue than with petrol. Testing comes at the end: before that, clean diesel is added, and the filter is cleaned or replaced as needed. Then our engineers start the engine and make sure it runs correctly before we go. Most jobs are done in about half an hour after our technicians get there, provided your motor hasn't run — and the pumps our engineers use are fine on a live forecourt and quiet at night outside a house. Your insurer will ask for an engineer's report and the VAT invoice, and both are yours once the job is done. Payment comes on the day, with no money upfront. Wrong-fuel cover is included in many insurance policies — and so use the wait to look at yours. ## About Wenvoe, for a moment Wenvoe is a small village in the Vale of Glamorgan, situated inland at an elevation of 54 metres, approximately 4 miles west of Cardiff. Wenvoe has a population of around 1129 residents, with predominantly detached housing. Wenvoe is close to nearby settlements such as Wallston and St Lythans, and is located near the historic site of Twyn-yr-odyn. Wenvoe remains a quiet residential community on the outskirts of the Cardiff urban area. ## AdBlue drains round Wenvoe, and The Vale of Glamorgan beyond Being a rural village, Wenvoe has the same vans as surrounding areas — Twyn-yr-odyn, St Lythans — all the way through CF postcodes and the wider area beyond. Fastest of all: quote a CF5 6 postcode to our van. The vehicle remains put. Our engineers drain it where it is — a side street close to St Mary's Church, a lay-by on the way to Wenvoe Wood, a drive. Tricky to pin down, like the back of TK Maxx? By a border? Asking beats assuming, and so ring. ## For Wenvoe motorists, the short version Read the cap before you pour. Even so AdBlue in your diesel tank? Petrol in Diesel can drain it where it stands, wherever around The Vale of Glamorgan: keep the vehicle off and ring 0333 366 0103.