--- title: Explained: AdBlue in a Diesel Tank Newmarket canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/newmarket-suffolk/ location: Newmarket county: Suffolk latitude: 52.243640 longitude: 0.405270 service: AdBlue in a Diesel Tank updated: 2026-10-15 --- # AdBlue in a Diesel Tank in Newmarket: How It Happens and How to Prevent It AdBlue already in your diesel tank? Then set this page down for now, leave the ignition and motor off, then phone 0333 366 0103. Around Newmarket, finding it before your engine turns normally leaves draining and a thorough flush where it stands. If you are reading before it has happened, the remainder of this page is about why it occurs and how to make sure it does not. ## Two fillers, two tanks: AdBlue in a diesel vehicle Diesel feeds the engine — but plenty of current diesels driven around Newmarket and Woodditton carry another liquid as well. The exhaust, not the engine, is where AdBlue ends up: sprayed into the gas to clean them, from a separate tank. Different tanks, separate fillers. Many of vehicles share a single flap for the two, while some move the AdBlue filler to your boot or under the bonnet. The diesel side is fuelled at the pump all the time. Seldom topped up, AdBlue usually comes out of a bottle, tipped by someone who has to stop and think what cap to use. Mistakes happen in the gap between them. ## Newmarket: how AdBlue in the diesel tank takes place Carelessness rarely explains it. What does is three things coming up at once. On a drive off Kingston Passage before work, or in the car park at The Bushel on the way home: that is where the hurried top-up takes place. Why the rush? As AdBlue runs low the car tells you, and once it is gone, limp mode kicks in. The old car's cap is where your hand goes — but a rental car, a new car or a company car puts the fillers somewhere else. That is a second thing: a strange vehicle. No part stops the pour after it has started, since a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. Studlands Park or the middle of Newmarket: it takes the same few seconds either way. ## Telling the AdBlue filler from the diesel filler Before you tip anything, whether on a drive in Stetchworth or a forecourt around Newmarket, check these. They take a few seconds. - Read the cap instead of going by where it sits: AdBlue caps are frequently blue or marked "AdBlue", and diesel ones normally aren't. - Check the size: the smaller filler neck is, on many cars, the AdBlue one. - The flap. Look inside the fuel flap for a label. Many vehicles say there which fuel goes where. - The handbook says where it lives if your filler isn't next to your diesel cap: your boot, or under the bonnet. - 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 the nearest station. ## Topping up AdBlue without it reaching the diesel tank Wherever around Suffolk the light comes on, this is a routine for that day. - Switch off once parked — flat ground, motor off, and not in a rush by Wellington Street at the roadside. - Daft as it sounds, speaking "AdBlue" aloud as you unscrew the cap does the trick — once you've located your filler and read the cap. - Leave your 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. - Close the cap, and check again — making sure your diesel cap remained closed the whole time. After that, start your car. Stop there if you find, at step two or three, that you have already poured into your diesel side. Never carry on to stage five. ## Put AdBlue in your diesel tank in Newmarket already? What follows is a short order of things, beginning with no starting your motor. Do not switch the ignition on; on plenty of diesels that alone runs the fuel pump. AdBlue doesn't mix with diesel — it sinks to the bottom of that tank, where your fuel is drawn from — so do not top up with diesel to dilute it. On a forecourt — BP, Shell or another — the staff will normally help roll the vehicle away, when you ask. Leave it where it is if you are on your own drive in Newmarket. Stop as soon as it is safe and switch off, if your engine has already run. The next exit is where to leave if you are on the M11, under 15 miles from Newmarket. Tell us about how far it went: a run towards Ely, under 15 miles away, is a bigger job than a short hop across Newmarket. ## Our arrival in Newmarket, and what occurs next The van reaches the car anywhere it has come to rest — your own driveway, beside The Stable, or by All Saints Church of England Primary School, Newmarket. Both the work and the quote rest on three replies — what fluid, which amount, and if it has run — so our engineers ask. You hear that price by phone, before anyone sets off. The system is then purged thoroughly, once that tank is cleared. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own. Testing comes last: before that, clean diesel goes in, and your filter is cleaned or replaced if necessary. We do not leave until it has been started and is running smoothly. Unrun cars usually mean a half-hour visit after the moment we arrive. The equipment is fine on a busy filling station, and hushed enough for a residential street after dark. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Plenty of insurance policies include misfuelling cover, and so it's worth checking yours whilst we are on the way. ## About Newmarket and where it is Newmarket is a town in Suffolk, situated inland in the eastern region of England, approximately 55.7 miles from London. Newmarket sits at an elevation of 29 metres, near the villages of Exning and Snailwell, and is close to the city of Ely. Newmarket has a population of around 14,065 people, predominantly living in terraced housing. Newmarket is also near Studlands Park, a notable local area. ## AdBlue drains around Newmarket, and Suffolk beyond Over CB postcodes, the vans that cover Newmarket — a town — work the nearby places too, Snailwell and Exning included. Fastest of all: quote a CB8 8 postcode to our van. There's no need to shift the vehicle. A driveway, a lay-by on the way to Memorial Hall Gardens, a side street close to Newmarket Market: we drain the vehicle where it is. If you're near a boundary, or somewhere hard to describe like the back of Palace House: National Horseracing Museum, ring and ask rather than assuming. ## Newmarket people: the short version Always, the cap; then, the pour. Petrol in Diesel empties it on the spot, anywhere across Suffolk, if AdBlue has gone in the diesel tank regardless — so leave it off and ring 0333 366 0103.