--- title: Mersham: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/mersham-kent/ location: Mersham county: Kent latitude: 51.121200 longitude: 0.932070 service: AdBlue in a Diesel Tank updated: 2026-10-26 --- # Preventing AdBlue in a Diesel Tank in Mersham: Why It Happens Keep the motor and ignition off and phone 0333 366 0103 now — the rest can wait when AdBlue is already in the diesel tank. In Mersham, catching it before your engine runs normally means a drain and a thorough flush where it stands. If you are reading before it has happened, the rest of this page is about why it occurs and how to make sure it does not. ## Two fillers, two tanks: AdBlue in a diesel car Many newer diesels on the roads around Mersham and Broad Oak carry two liquids, not one. Diesel goes to the engine. Its own tank holds it, and from there it is sent to your exhaust, and there spraying treats the fumes. Each tank has its own filler. Under one flap, side by side: that's the layout on a lot of vehicles. Elsewhere, AdBlue's filler is under the bonnet or in your boot instead. The diesel side is topped up at the petrol pump all the time. Rarely filled, AdBlue normally goes in out of a bottle, tipped by a driver who must stop and think which cap to use. That gap is where the mistake lives. ## How does AdBlue in the diesel tank occur in Mersham? It's rarely carelessness. Three things tend to line up. Haste comes from the warning. The car tells you as AdBlue runs low, and a dry tank sends it into limp mode — so the top-up gets done in a rush, before work on a drive off Oaklands, or on the way home in the car park at Royal Oak. The old car's filler is where the hand reaches — but a rental car, a new car or a company car keeps the fillers somewhere else. That is the second factor: a strange vehicle. No part halts the pour after it has started, because a bottle with a spout goes into a diesel filler as readily as an AdBlue one. The bottle fits. The Forstal or the middle of Mersham: it is the same few seconds either way. ## Which filler is for AdBlue, and which for diesel? Be it a Mersham forecourt or a drive out in Hinxhill Park, spend a couple of seconds over these before any is poured in. - Colour and marking: an AdBlue cap is frequently blue, or says "AdBlue", where a diesel cap normally does not. Trust the cap, not its position. - Look at the size: the smaller neck is, on many cars, the AdBlue one. - A label inside your fuel flap often shows which fuel goes where, on plenty of motors. Check for it. - The handbook. If the filler is not by the diesel cap, it's in your boot or under the bonnet, and the handbook says which. - The person who drove the car last. On a hire or company car collected from somewhere like the car park outside Ashford International, ask before you leave, not when the light comes on. ## AdBlue top-ups that never reach your diesel tank Wherever around Kent the light comes on, this is a routine for the day. - Not in a rush on the side of Kingsford Street, not on a slope, not with the motor running: park and switch off first. - Find the AdBlue filler, check the cap, and say the word "AdBlue" out loud while you unscrew it. It sounds silly. It works. - Leave the diesel cap on. If both sit under one flap, check the diesel cap is still closed before you lift the bottle. - Tip slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Shut the cap, and check once more — making sure the diesel filler remained shut throughout. After that, start the car. Stop there if you find, at step two or three, that you have already poured into your diesel side. Skip step five entirely. ## Put AdBlue in the diesel tank in Mersham already? Don't start the motor: that's where the short order of things starts. Don't switch the ignition on; on plenty of diesels that alone runs the fuel pump. Thinning it with extra diesel fails, since AdBlue settles to the bottom instead of mixing — and that is where your fuel is sucked from. If you are at a forecourt, whether it's the Tesco or the John Childs Garages, ask the staff to help roll your car away from the pump. Your own driveway around Mersham is the place it should stay. Where your engine has run already, stop somewhere safe and turn the vehicle off. Mersham sits under a mile from the M20; there, use the first exit. Tell us about how far it went: a run towards Canterbury, under 15 miles away, is a bigger job than a short hop across Mersham. ## What takes place when our engineers arrive around Mersham Wherever your car has stopped, be it by Mersham Primary School, near St. John Baptist Church, Mersham or on your own drive, the van travels to it. Both the work and our quote depend on three answers — what liquid, what amount, and whether it's run — so our engineers ask. The quote comes on the call, ahead of any van leaving. After that: draining, then a full flush of the entire system. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own. Testing is last: before that, fresh diesel is added, and your filter is flushed or replaced if necessary. Next we start the car and check it runs correctly before we go. Most jobs are done in roughly half an hour once we get there, provided your motor hasn't run — and the pumps we use are safe on a live forecourt yet quiet after dark outside a house. No money upfront; you settle up that day. Afterwards, the VAT invoice and the report from the engineer go to you for the insurer. While we travel, take a look at your insurance documents; plenty include cover for misfuelling. ## About Mersham itself Mersham is a small village in Kent, situated inland at an elevation of around 70 metres, and is located approximately 53 miles from London. Mersham has a population of around 770 people and is characterised by predominantly detached housing. Mersham is close to the nearby places of The Forstal, Sevington, and Ridgeway, and is about 12.7 miles from the city of Canterbury. ## AdBlue drains in Mersham and across Kent Over TN postcodes, the vans that cover Mersham — a rural village — work the nearby places too, Ridgeway and Sevington included. Quickest of all: give a TN25 6 postcode to our van. The vehicle does not need to shift. Wherever it sits — beside Dreamshapes Crafts, in a lay-by en route to Mersham (Millennium Green), on a drive — that's where it is cleared. Ring and ask instead of guessing if you are near a boundary, or somewhere hard to explain, like the back of St Mary. ## Mersham people: the short version Before you pour, read the cap. Petrol in Diesel drains it on the spot, anywhere in Kent, if AdBlue has gone in your diesel tank all the same — and so leave it off then ring 0333 366 0103.