--- title: Explained: AdBlue in a Diesel Tank Knighton canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/knighton-leicestershire/ location: Knighton county: Leicestershire latitude: 52.608030 longitude: -1.112330 service: AdBlue in a Diesel Tank updated: 2026-10-23 --- # AdBlue in a Diesel Tank in Knighton: How It Occurs and How to Avoid It If AdBlue is already in your diesel tank, stop reading for a moment: leave your motor and your ignition off then call 0333 366 0103. A drain and a thorough flush, carried out right where the vehicle sits in Knighton, is normally what it takes when found before your motor runs. If you are reading before it has happened, the remainder of this page is about why it occurs and how to make sure it doesn't. ## AdBlue in a diesel vehicle: two tanks, two fillers Plenty of current diesels on the roads round Knighton and Clarendon Park carry two liquids, not one. Diesel goes to your engine. The exhaust, not your motor, is where AdBlue ends up: dosed into the fumes to fresh it, from its own tank. Separate tanks, different fillers. Under one flap, side by side: that is the layout on a lot of vehicles. On others, AdBlue's filler is beneath the bonnet or in the boot instead. Diesel gets filled on each forecourt call-out, week in, week out. Much less frequently, the AdBlue side gets topped up — mostly from a bottle, by a person thinking about where it goes. Mistakes happen in the gap between them. ## How does AdBlue in the diesel tank occur around Knighton? Carelessness rarely explains it. Instead is three things coming up at once. Haste comes from the warning. The car warns you as AdBlue runs low, and a dry tank puts it into limp mode — so the top-up gets done in a rush, before work on a drive off Balmoral Close, or on the way home in the car park outside The Cradock Arms. Next, the hand reaches for the cap it would have used on the old motor — because a rental car, a new motor or a company car puts the fillers somewhere your last one didn't. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, and so nothing stops the tip once it has started. Whether it takes place in South Knighton or the middle of Knighton, it's the same few seconds. ## Telling the AdBlue filler from the diesel filler A couple of seconds is all these take — so check them before you tip anything, on a driveway in Knighton Fields or a forecourt around Knighton. - Where it sits can mislead; the cap doesn't. AdBlue ones tend to be blue or bear the name "AdBlue" — diesel caps normally don't. - Look at the size: the smaller filler neck is, on many cars, the AdBlue one. - Open the flap and look for a label — plenty of cars mark what goes in each inlet right there. - Cannot find it next to your diesel inlet? In that case look below the bonnet or in the boot — the owner's manual says which. - The person who drove the vehicle last. On a hire or company car collected from somewhere like the car park at Leicester, ask before you leave, not when the light comes on. ## How to top up without AdBlue in the diesel tank Anywhere around Leicestershire the light comes on, this is a routine for that day. - Not in a rush on the side of Carisbrooke Road, not on a slope, not with your engine running: park then switch off properly. - Say "AdBlue" out loud as you unscrew the cap, after you find the AdBlue filler and reading it. Silly, yes, but it works. - Leave your diesel cap on. If both sit under one flap, check your diesel cap is still closed before you lift the bottle. - Using the bottle's own spout, pour slowly — and stop when it's full or the bottle is empty. - Only then, start the car: close the cap, check once more, and make sure your diesel cap was never opened. Find at step two or three that it's already gone into the diesel side? So stop just there. Never go on to stage five. ## Put AdBlue in the diesel tank in Knighton already? The short order of things, starting with not starting your engine. Don't switch the ignition on; on plenty of diesels that alone runs the fuel pump. Diluting it with more diesel fails, because AdBlue sinks to the base instead of mixing — and that is where your fuel is drawn from. The attendants at Gulf, Shell or another forecourt will usually lend a hand pushing the car clear when asked. Leave it where it is if you're on your own drive in Knighton. Where your motor has run already, pull over safely then switch it off. The next exit is where to come off when you're on the M1, under 5 miles from Knighton. Tell us about how far it went: a run towards Leicester, under 3 miles away, is a bigger job than a short hop across Knighton. ## What occurs when we arrive in Knighton By St Thomas More Catholic Voluntary Academy, near Carisbrooke Tennis Club or on your own driveway: wherever the car has stopped, our technicians come to it. Those answers decide the work and the price, so our engineers ask what was put in, roughly how much, and whether it's run. No one heads out before you've had the price by phone. Your system is then rinsed thoroughly, once that tank is emptied. Much more than with petrol, it counts here: the crystals build up, some metals corrode, and nothing washes away unaided, no matter how long it sits. Once the fuel filter has been cleaned — or renewed, where needed — fresh diesel goes in, and finally your car gets tested. Before we leave, our technicians fire it up and check that it's running smoothly. Using pumps safe on a working forecourt and quiet enough for use outside a house at night, most jobs in which your engine has not run take roughly half an hour after we arrive. Payment happens on the day, not upfront, and you are given the paperwork an insurer asks for: an engineer's report and a VAT invoice. While we travel, take a look at your policy; many carry cover for misfuelling. ## About Knighton Knighton is a suburban area in Leicestershire, situated on the riverside near Leicester, with a mix of semi-detached housing and local amenities. Knighton sits at an elevation of around 80 metres, close to the city centre and nearby places like South Knighton and Stoneygate. Knighton is home to a population of approximately 6735 residents, living in a predominantly residential area. Knighton is located about 2 miles from Leicester city centre, making it a convenient location for commuters. ## Knighton and Leicestershire: AdBlue drains across the area Knighton is a residential suburb, and the vans that cover it also work the places near it, West Knighton and Stoneygate among them, across the LE postcode area. A postcode starting LE2 3 gets the van to you fastest. The vehicle remains where it is. Wherever it sits — beside Leicester Bowling Club, on a layby en route to Attenborough Arboretum, on a drive — that is where it is drained. If you're near a border, or somewhere hard to describe like the back of Knighton Parish Centre, ring and ask rather than assuming. ## For Knighton motorists, the short version Before you tip, read the cap. Petrol in Diesel drains it on the spot, anywhere around Leicestershire, if AdBlue has gone in your diesel tank regardless — so leave it off and phone 0333 366 0103.