--- title: Explained: AdBlue in a Diesel Tank Mollington canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/mollington-oxfordshire/ location: Mollington county: Oxfordshire latitude: 52.123140 longitude: -1.358520 service: AdBlue in a Diesel Tank updated: 2026-10-24 --- # How It Occurs and How to Avoid It: AdBlue in a Diesel Tank in Mollington Leave the motor and ignition off and call 0333 366 0103 first — the rest can wait when AdBlue is already in the diesel tank. Caught before the engine runs, it's generally a drain and a thorough flush, done where your car is around Mollington. If you're reading before it has happened, the remainder of this page is about why it occurs and how to make sure it doesn't. ## Why does AdBlue in a diesel car need its own filler? Plenty of newer diesels in Clattercote, as well as Mollington, run on two liquids; your motor gets just the diesel. AdBlue goes to your exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Different tanks, different fillers. Other cars put the AdBlue filler in the boot or under the bonnet; plenty of others place both together behind one flap. At the petrol pump, the diesel side gets filled constantly. Much less regularly, the AdBlue side gets topped up — mostly from a bottle, by someone working out where it goes. The mistake grows in that gap between them. ## AdBlue in your diesel tank in Mollington: how it takes place Three things tend to line up, and carelessness is seldom one of them. The warning comes first. As AdBlue runs low the vehicle tells you, and if it runs out completely, the vehicle goes into limp mode. So the top-up is done in a hurry: on a driveway off Main Street before work, or in the car park at Green Man on the way home. Then the vehicle is unfamiliar. A hire car, a new vehicle or a company car puts the fillers where your last one did not, and your hand gets to for the cap it would have used on the old one. A spout-topped bottle finds no obstacle at a diesel filler any more than at an AdBlue one. And so the pour, once begun, keeps on. It's a few seconds, whether out in Shotteswell or right in the heart of Mollington. ## How to tell the AdBlue filler from the diesel one A few seconds is all the checks take — so check them before you tip anything, on a drive in Warmington or a forecourt in Mollington. - Read the cap instead of going by position: AdBlue caps are regularly blue or marked "AdBlue", and diesel caps usually are not. - On plenty of cars, the size gives it away: AdBlue gets the smaller filler neck. - The flap. Look inside your fuel flap for a label. Many motors say there which fuel goes where. - In the boot or under the bonnet: that's where the filler sits if it's not by your diesel cap, and the handbook says which. - Check with the person who drove it last — before you leave, not when the light comes on — when you collect a hire or company car from somewhere like the car park at Banbury. ## Keeping AdBlue out of the diesel tank when you top up For the day the warning appears — anywhere you are across Oxfordshire — a simple routine to use. - Switch off once parked — level ground, engine off, and never rushed by The Holt at the roadside. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds silly and it does the trick. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave it on. - Gently is best, through the bottle's own spout, till it is full or the bottle runs out. - Before you start your car, shut the cap and check again that your diesel cap was never opened off. If at step two or three you find you have already poured into the diesel side, stop there. Do not go on to stage five. ## AdBlue in the diesel tank already, in Mollington? Do not start your motor: that's where the short order of things starts. On plenty of diesels your ignition alone runs the fuel pump, so don't switch the car on. Topping up with diesel won't weaken it: instead, AdBlue sinks to the bottom of your tank, just where fuel is taken from. Ask the attendants to help push your car away from the petrol pump if you're at a forecourt — the the nearest petrol station, the Tesco or somewhere else. At home around Mollington? Then the vehicle remains where it is. If the engine has already run, stop as soon as it is safe then switch off. On the M40, under a mile from Mollington, that means the next junction. About how far did it go? Crossing Mollington is smaller work than a run of under 25 miles to Coventry, so say. ## When our engineers turn up around Mollington, what takes place? Our van reaches the car anywhere it has come to rest — your own drive, near All Saints, or outside Cropredy Church of England Primary School. Those replies settle this work and the quote, so we ask what got in, about how much, and if it's run. No one heads out until you've heard the price over the phone. Then that tank is drained and the fuel system rinsed thoroughly. Much more than with petrol, it matters with AdBlue: the crystals form, certain metals corrode, and none of that washes away unaided, no matter how long it is left. A test is at the end: before that, clean diesel is added, and the fuel filter is flushed or changed as needed. Your engine is started next and checked to be sure it runs properly, all before we go. Unstarted cars usually mean a half-hour visit after the moment we arrive. The equipment is safe on a busy forecourt, and hushed enough for a residential street after dark. Nothing in advance; you settle up that day. Afterwards, a VAT invoice and a report from the engineer are handed to you for your insurer. Wrong-fuel cover is included in many insurance policies — so use the wait to look at yours. ## About Mollington itself Mollington is a small village in Oxfordshire, situated inland at an elevation of around 142 metres. Mollington lies near the villages of Shotteswell and Farnborough, and is characterized by its predominantly detached housing stock. Mollington is located approximately 20 miles from Coventry and 67 miles from London, making it a rural community with some commuter links. ## AdBlue drains about Mollington, and Oxfordshire beyond Over OX postcodes, our teams covering Mollington — a rural village — work the surrounding spots too, Great Bourton and Farnborough among them. A postcode starting OX17 1 gets the van to you fastest. The car remains put. A driveway, a lay-by on the way to Angel Piece, a side street near Obelisk: our engineers drain the car where it sits. Guessing doesn't help at the back of Farnborough Hall, close to a border, or anywhere hard to pin down; phone and check. ## Mollington people: the short version Before you pour, read the cap. Still AdBlue in the diesel tank? Petrol in Diesel will drain it where it stands, anywhere in Oxfordshire: switch the vehicle off and phone 0333 366 0103.