--- title: AdBlue in a Diesel Tank Datchet? Read This canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/datchet-berkshire/ location: Datchet county: Berkshire latitude: 51.483980 longitude: -0.578520 service: AdBlue in a Diesel Tank updated: 2026-10-09 --- # Preventing AdBlue in a Diesel Tank in Datchet: Why It Happens Leave your engine and ignition off then phone 0333 366 0103 first — the rest can wait if AdBlue is already in your diesel tank. Caught before the engine runs, it's normally a drain and a thorough flush, done where the vehicle is in Datchet. If you're reading before it has happened, the rest of this page is about why it happens and how to make sure it doesn't. ## AdBlue in a diesel motor: two tanks, two fillers Diesel feeds your engine — but many current diesels seen round Datchet and Upton Park hold another fluid too. AdBlue's own tank holds it, and from there it goes to the exhaust, and there spraying cleans the fumes. Separate tanks, separate fillers. Plenty of vehicles share a single flap for both, whereas others put the AdBlue filler to the boot or under the bonnet. The diesel side is fuelled at the pump all the time. A driver who has to stop and work out where it goes usually fills the AdBlue side, from a bottle, and far less frequently. It's in that gap that the slip lives. ## AdBlue in your diesel tank in Datchet: how it takes place Three things tend to line up, and carelessness is rarely one of them. The warning comes first. As AdBlue runs low the vehicle tells you, and if it runs out altogether, the car goes into limp mode. So the top-up is done in a hurry: on a drive off London Road before work, or in the car park outside The Royal Stag on the way home. The old car's filler is where your hand reaches — but a hire car, a new vehicle or a company car keeps the fillers somewhere else. That's the second thing: a new car. Nothing stops the pour after it has started, since a bottle with a spout goes into a diesel filler as readily as an AdBlue one. The bottle fits. Whether it occurs in Datchet Common or the middle of Datchet, it's the same few seconds. ## Telling the AdBlue filler from your diesel filler A couple of seconds is all the checks take — so check them before you tip anything, on a driveway in Sunnymeads or a forecourt around Datchet. - Where it sits can mislead; the cap does not. AdBlue ones are often blue or bear the name "AdBlue" — diesel caps usually don't. - The size. On plenty of vehicles the AdBlue filler neck is the smaller of the two. - The flap. Look inside your fuel flap for a label. Many motors say there which fuel goes where. - Can't find it beside the diesel inlet? Then check beneath the bonnet or in the boot — the owner's manual will say which. - The person who drove it last. On a hire or company car picked up from somewhere like the car park at the nearest station, ask before you leave, not when the light comes on. ## How to top up without AdBlue in the diesel tank A routine for the day the light comes on, wherever around Berkshire that is. - Park then switch off. Not on a slope, not with your motor running, and not in a rush on the side of The Green. - Say "AdBlue" out loud as you unscrew the cap, once finding the AdBlue filler and read it. Daft, yes, yet it works. - The two under one flap? So make sure the lid on the diesel side stays shut ahead of raising the bottle. - Pour slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty. - Before you start the car, close the cap and look a second time that the diesel cap never came off. Spot at stage two or three that it has already gone into the diesel side? So stop just there. Leave out step five altogether. ## AdBlue in the diesel tank already, in Datchet? Then the order of things is short. Do not start the motor. Leave your ignition off as well, since on many diesels switching it on by itself starts your pump. AdBlue doesn't mix with diesel — it sinks to the bottom of the tank, where your fuel is drawn from — so don't top up with diesel to thin it. Ask the attendants to help roll the vehicle away from the petrol pump if you're at a forecourt — the Texaco, the Esso or anywhere else. Your own driveway in Datchet is where it should stay. When your motor has been run already, stop somewhere safe then switch the car off. Come off the M4 — under a mile out of Datchet — at the first exit. Roughly how far did it go? Crossing Datchet is less a job than a trip of under 25 miles to Westminster, so tell us. ## When our engineers turn up in Datchet, what takes place? Our van reaches your car anywhere it stopped — your own drive, near St Mary the Virgin, or by Datchet St Mary's CofE Primary School. Which fluid got in, the amount, and if it ran: our technicians ask since those replies set both work and price. Nobody heads out before you've had our quote by phone. Emptying the tank comes next, then a full flush of your system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own — which is why the flush counts more here than with petrol. The filter is flushed, or replaced where it needs to be; fresh diesel goes in; and the car is tested. The engine is started next and checked to confirm it runs correctly, all before our technicians go. If your engine has not run, the majority of jobs take about half an hour once we are there, using pumps that are fine on a busy forecourt and quiet enough to use outside a house after dark. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Wrong-fuel cover is part of plenty of insurance policies — and so use the wait to look at yours. ## About Datchet and where it is Datchet is a village situated on the River Thames in Berkshire, with Datchet being a popular location for those who enjoy riverside walks and scenic views. Datchet has a mix of old and new housing, with detached homes being the predominant type, and Datchet benefits from its proximity to London, being approximately 19.5 miles from the city centre. Datchet is surrounded by open spaces, including Datchet Common, and Datchet is close to nearby places such as Upton and Myrke. ## AdBlue drains around Datchet, and Berkshire beyond Throughout SL postcodes, the vans covering Datchet — a village — work the surrounding locations too, Myrke and Upton included. Fastest of all: give a SL3 9 postcode for our van. The vehicle doesn't need to shift. A driveway, a lay-by on the way to Datchet Golf Club, a side street near Remote World Model Car Club: our engineers drain the vehicle where it sits. If you're close to a border, or somewhere hard to explain like the back of Ditton Park Manor, ring and ask instead of guessing. ## The short version for Datchet people Pour nothing until you've read the cap. AdBlue in the diesel tank after all? Keep the car switched off then ring 0333 366 0103; Petrol in Diesel drains it on the spot, across Berkshire.