--- title: Hersham: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/hersham-surrey/ location: Hersham county: Surrey latitude: 51.365630 longitude: -0.399400 service: AdBlue in a Diesel Tank updated: 2026-10-03 --- # AdBlue in a Diesel Tank in Hersham: How It Occurs and How to Prevent It If AdBlue is already in your diesel tank, stop reading for a moment: leave the motor and the ignition off and phone 0333 366 0103. Around Hersham, finding it before the motor turns usually means draining and a thorough flush on the spot. Not happened yet? Below, the rest of the page explains the why it occurs and the how to avoid it for good. ## AdBlue in a diesel motor, and its separate tank Not one liquid but two: that is what plenty of modern diesels near Hersham and Ashley Park run, with diesel for the engine. Its own tank holds it, and from there it goes to the exhaust, where spraying treats the fumes. Every tank comes with a filler of its own. On a lot of motors the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. At the petrol pump, your diesel side is topped up constantly. Seldom topped up, AdBlue normally comes from a bottle, poured by a driver who must stop and think what filler it needs. The mistake lives in that gap. ## Hersham: how AdBlue in the diesel tank takes place 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 running dry leads to limp mode — hence a hurried top-up, perhaps before work off Queens Road, perhaps at The Watermans Arms on the way home after work. Next, your hand reaches for the cap it knew on the old car — because a hire car, a new car or a company car puts the fillers somewhere your last one didn't. Lastly, the bottle goes in: diesel filler or AdBlue filler, it slides in just as easily, and after the tip starts, no part halts it. The same few seconds settle it, in the middle of Hersham or out in West End. ## The AdBlue filler and your diesel filler: telling them apart Be it a Hersham forecourt or a drive over in Claremont Park, take a couple of seconds on these before any goes in. - Read the cap rather than going by position: AdBlue ones are frequently blue or marked "AdBlue", and diesel ones usually are not. - Check the size: the smaller neck is, on many vehicles, the AdBlue one. - Lift the filler flap and check for a label — many cars show which goes in which filler right there. - Can't find it next to your diesel filler? Then look below the bonnet or inside your boot — the owner's manual will say where. - Ask the person who drove it last — before you leave, not when the light comes on — if you collect a hire or company car from somewhere like the car park at Walton-On-Thames. ## Keeping AdBlue out of your diesel tank when you top up The day the light goes on, wherever around Surrey, follow this routine. - Park and switch off. Not on a slope, not with your motor running, and not in a rush on the side of Molesey Road. - Silly as it sounds, saying "AdBlue" out loud as you unscrew the cap works — once you have found the filler and read the cap. - If both sit under one flap, check the diesel cap is still closed before you lift the bottle — and leave it on. - Stop when your tank is topped up or the bottle is empty; before that, pour slowly using the own spout. - Before starting your car, shut the cap and check a second time that the diesel cap was never opened off. Find at the second or third stage that AdBlue went in the diesel tank? That's where you stop. Stage five is off limits. ## Already put AdBlue in your diesel tank around Hersham? Don't start the engine: that is how the short order of things begins. On many diesels the ignition alone runs the fuel pump, so do not switch the vehicle on. Don't top up with diesel to thin it: AdBlue does not mix with diesel, it sinks to the bottom of the tank, where the fuel is drawn from. At a forecourt — Texaco, BP or another — the attendants will usually help push the vehicle clear, if you ask. Leave it where it is if you're on your own drive in Hersham. If your engine has already run, stop as soon as it is safe then switch off. Hersham sits under 5 miles from the M3; there, use the first exit. A short hop across Hersham is a smaller job than a run towards Westminster, under 25 miles away, and so tell us roughly how far it went. ## What occurs when our engineers arrive around Hersham The van reaches your car wherever it stopped — your own driveway, beside Hersham War Memorial, or outside Burhill Primary School. Which liquid was put in, the amount, and if it ran: our technicians ask because the answers set both work and price. During the phone call itself, you are told the quote — before anything else. Then the tank is cleared and the system purged thoroughly. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own — which is why that matters more with AdBlue than with petrol. The fuel filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and the car is tested. Next our technicians start it and check it runs properly before leaving. If the engine hasn't run, the majority of 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. Nothing upfront; you settle up on the day. At the end, a VAT invoice and a report from the engineer are handed to you for your insurer. Misfuelling cover is part of many insurance policies — and so make use of the wait to check yours. ## About Hersham itself Hersham is a village in Surrey, situated on the riverside at an elevation of 19 metres, with semi-detached housing being the predominant type of accommodation. Hersham lies approximately 15 miles from London and is close to nearby places such as West End, Rydens, and Burwood Park. Hersham has a population of around 4535 residents and is located near the city of Westminster. Hersham's riverside setting provides a unique character to the village. ## AdBlue drains in Hersham and across Surrey Hersham is a village, and the teams that cover it also work the places near it, Rydens and Burwood Park among them, across the KT postcode area. Quickest of all: quote a KT12 5 postcode for the van. Shifting the car isn't necessary. Our technicians drain it where it is — a side street near Hersham Village Hall, a lay-by on the way to Hersham Green, a driveway. Ring and ask rather than assuming if you're near a boundary, or somewhere hard to describe, like the back of Hersham Centre for the Community. ## For Hersham motorists, the short version Read the cap before you tip. If AdBlue has gone in your diesel tank all the same, leave the car off then ring 0333 366 0103. Petrol in Diesel clears it where it stands, anywhere across Surrey.