--- title: AdBlue in a Diesel Tank South Wimbledon: Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/south-wimbledon-greater-london/ location: South Wimbledon county: Greater London latitude: 51.416190 longitude: -0.193550 service: AdBlue in a Diesel Tank updated: 2026-10-08 --- # AdBlue in a Diesel Tank in South Wimbledon: Why It Occurs and How to Prevent It Stop reading a minute when your diesel tank already holds AdBlue in it: ignition off, engine off, then ring 0333 366 0103. A drain plus a thorough flush, done just where your car stands in South Wimbledon, is normally what it takes when caught before the engine runs. Not happened yet? Further down, the page covers the reasons it occurs and the how to avoid it altogether. ## Two fillers, two tanks: AdBlue in a diesel motor Plenty of newer diesels on the roads round South Wimbledon and Colliers Wood carry two liquids, not one. Diesel goes to your engine. AdBlue goes to the exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own. Each tank comes with a filler of its own. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in your boot or under the bonnet. Diesel goes in at every forecourt call-out, again and again. Much less often, the AdBlue side gets filled — mostly from a bottle, by someone working out where it goes. The mistake lives in that gap. ## South Wimbledon: how AdBlue in the diesel tank occurs Seldom is it carelessness: usually three things line up. The warning comes first. As AdBlue runs low the car tells you, and if it runs out completely, your vehicle goes into limp mode. So the top-up is done in a hurry: on a driveway off Balfour Road before work, or in the car park outside Horse & Groom on the way home. The old car's filler is where your hand reaches — yet a rental car, a new motor or a company car puts the fillers somewhere else. That's the second factor: an unfamiliar vehicle. 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 after it has started. Merton Park or the middle of South Wimbledon: it takes the same few seconds in both. ## Which filler is for AdBlue, and which for diesel? Before you tip anything, whether on a driveway in Tooting Graveney or a forecourt in South Wimbledon, check these. They take a couple of seconds. - The cap. The AdBlue cap is frequently blue, or marked "AdBlue". Your diesel cap normally is not. Read it rather than going by where it sits. - Look at the size: the smaller neck is, on plenty of cars, the AdBlue one. - The flap. Look inside the fuel flap for a label. Many vehicles say there which fuel goes where. - In the boot or under the bonnet: that is where the filler is if it's not by your diesel cap, and the handbook tells you which. - Ask 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 Wimbledon. ## How to top up without AdBlue in your diesel tank Wherever across Greater London the light comes on, here is a routine for the day. - Park then switch off. Not on a slope, not with your motor running, and not in a rush on the side of Kingston Road. - Find the AdBlue filler, check the cap, and say the name "AdBlue" out loud while you unscrew it. It seems silly. It does the trick. - Leave your diesel cap on. If both sit under one flap, check the diesel cap is still closed before you lift the bottle. - Using the bottle's own spout, tip slowly — and stop when it is full or the bottle is empty. - Close the cap, and check again — making sure the diesel cap stayed closed the whole time. Only then, start the car. Find during the second or third step that AdBlue went in the wrong tank? That's where you stop. Leave out stage five altogether. ## Put AdBlue in the diesel tank around South Wimbledon already? Do not start your engine: that's where the short order of things begins. On plenty of diesels the ignition alone runs the fuel pump, and so do not switch it on. AdBlue doesn't mix with diesel — it sinks to the bottom of your tank, where your fuel is pulled from — so don't top up with diesel to thin it. Ask the attendants to help roll the vehicle clear of the petrol pump if you are on a forecourt — the Esso, the Sainsbury's or somewhere else. Leave it where it is if you're on your own drive in South Wimbledon. Already run? Stop once it's safe, then switch off. South Wimbledon lies under 10 miles from the M4; on it, take the next exit. Roughly how far did it go? Crossing South Wimbledon is less a job than a run of under 10 miles to Westminster, so say. ## Our arrival in South Wimbledon, and what takes place next Our technicians come to the vehicle wherever it has stopped, whether that is outside Pelham Primary School, near John Innes Youth Centre or on your own driveway. Our engineers ask what was put in, about how much, and whether it has run, because the answers determine this work and our price. You hear that price by phone, before anybody heads out. Your system is then purged thoroughly, after the tank is drained. Not like petrol, AdBlue forms crystals and eats at certain fuel-system metals, and neither washes out unaided. Hence it matters more. Your filter is cleaned, or replaced where it needs to be; clean diesel goes in; and the vehicle is tested. The engine is started next and checked to be sure it runs smoothly, all before we head off. If the motor has not run, the majority of jobs take about half an hour once we're there, using pumps that are fine on a busy forecourt and quiet enough to use outside a house at night. No money upfront; you settle up that day. At the end, a VAT invoice and a report from the engineer go to you for the insurer. While we travel, have a look at your policy; plenty include cover for misfuelling. ## About South Wimbledon and where it is South Wimbledon is a suburban area in southwest London, situated near the River Wandle and close to several other neighbourhoods, including Merton Park and Wimbledon. South Wimbledon has a relatively low elevation of 19 metres above sea level and is characterized by a high proportion of flat dwellings. South Wimbledon is located approximately 6.9 miles from central London, with Westminster just 6.5 miles away. South Wimbledon is a densely populated area, with around 14,849 residents, ## South Wimbledon and Greater London: AdBlue drains across the area South Wimbledon is a residential suburb, and our teams that cover it also work the towns near it, Merton and Wimbledon among them, across the SW postcode area. A postcode starting SW19 1 gets our van to you fastest. There's no need to move the car. A drive, a lay-by on the way to Nelson Gardens, a side street near Memorial of Lord Nelson: we drain the car where it sits. Assuming won't help at the back of St John The Divine, close to a boundary, or somewhere awkward to pin down; ring and ask. ## For South Wimbledon motorists, the short version Before you pour, read the cap. Petrol in Diesel drains it on the spot, anywhere across Greater London, if AdBlue has gone in your diesel tank all the same — and so leave the vehicle off then phone 0333 366 0103.