--- title: Explained: AdBlue in a Diesel Tank Earith canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/earith-cambridgeshire/ location: Earith county: Cambridgeshire latitude: 52.353770 longitude: 0.031140 service: AdBlue in a Diesel Tank updated: 2026-10-21 --- # Earith: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? If AdBlue is already in your diesel tank, stop reading for a moment: leave the motor and your ignition off and call 0333 366 0103. Around Earith, catching it before the engine turns normally means draining and a thorough flush on the spot. Not happened yet? Below, the page covers the reasons it occurs and the how to avoid it for good. ## AdBlue in a diesel motor: two tanks, two fillers Diesel feeds your motor — but plenty of newer diesels driven round Earith and Wood End hold a second liquid too. Your exhaust, not your engine, is where AdBlue goes: sprayed into the fumes to clean it, from its own tank. Each tank has its own filler. On a lot of cars the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. Diesel goes in at every filling station call-out, week in, week out. The AdBlue side is topped up far less frequently, normally from a bottle, and normally by someone who has to stop and think where it goes. That gap is where the mistake lives. ## Earith: how AdBlue in your diesel tank happens Rarely is it carelessness: usually three things line up. Hurry follows 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 driveway off Colne Road, or heading home in the car park outside The Crown. Then your car is unfamiliar. A hire car, a new vehicle or a company car puts the fillers where your last one did not, and the hand reaches for the cap it would have used on the old one. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, so nothing stops the tip once it has started. It's seconds, whether out in East End or bang in the centre of Earith. ## The AdBlue filler and the diesel filler: telling them apart Be it a Earith forecourt or a driveway over in Colnefields, take a few seconds on these before any goes in. - Read the cap rather than going by position: AdBlue caps are regularly blue or marked "AdBlue", and diesel ones normally aren't. - Many motors give AdBlue the smaller filler of the two. - A label inside your fuel flap frequently shows which fuel goes where, on many vehicles. Check for it. - The handbook says which it is if your filler isn't next to your diesel cap: the boot, or under the bonnet. - The person who drove the car last. On a hire or company car picked up from somewhere like the car park outside Waterbeach, ask before you leave, not when the light comes on. ## AdBlue top-ups that never reach your diesel tank The day the light goes on, anywhere across Cambridgeshire, use this routine. - Park then switch off. Not on a slope, not with your motor running, and not in a rush on the side of Chapel Road. - Say "AdBlue" out loud as you unscrew the cap, after finding the AdBlue filler and reading it. Daft, yes, but it does the trick. - The diesel cap stays on. Where both sit under a flap, confirm it's shut before lifting the bottle. - Stop when your tank fills or the bottle runs dry; until then, tip gently using its built-in spout. - Close the cap and check once more. Make sure your diesel cap was never opened. Only then start the car. Stop there if you find, at step two or three, that you have already poured into the diesel side. Leave out step five entirely. ## Earith: already put AdBlue in the diesel tank? Don't start the engine: that is how the short order of things begins. The fuel pump starts on many diesels as soon as your ignition is switched on — and so keep it off. AdBlue doesn't mix with diesel — it sinks to the bottom of that tank, where the fuel is pulled from — so do not top up with diesel to dilute it. Ask the staff to help push the car away from the petrol pump if you are at a forecourt — the BP, the Somersham Fast Fit - Cole & Day or somewhere else. Your own drive around Earith is where it stays. Stop as soon as it is safe then switch off, if the engine has already run. On the M11, under 10 miles from Earith, that means the next exit. A short hop across Earith is a smaller job than a run towards Ely, under 15 miles away, so tell us roughly how far it went. ## When our technicians get there in Earith, what happens? Anywhere the car has stopped, be it by Earith Primary School, beside Earith Village Sign or on your own drive, the van comes to it. Both the work and the quote depend on three replies — what liquid, which quantity, and if it has run — so our engineers ask. On the phone call itself, you hear the price — ahead of anything else. Next: draining, then a full flush of the entire system. Not like petrol, AdBlue leaves crystals and attacks some fuel-system metals, and none of that clears out unaided. Hence it counts more. Testing is at the end: before that, clean diesel is added, and the filter is flushed or changed as needed. Your engine is started next and checked to make sure it runs correctly, all before our technicians leave. Using pumps fine on a working forecourt and quiet enough for use outside a house at night, most jobs where the motor has not run take about half an hour after our technicians are there. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Misfuelling cover is part of many insurance policies — so make use of the wait to look at yours. ## About Earith Earith is a small village in Cambridgeshire, situated on the banks of the River Great Ouse at an elevation of around 10 metres. Earith lies near the cities of Ely and Cambridge, and is surrounded by other villages such as East End, Bluntisham, and Colne. Earith has a population of approximately 1092 people, and its housing stock is predominantly made up of detached homes. Earith is located about 58.9 miles from London, making it a rural community with easy access to the capital. ## AdBlue drains across Cambridgeshire, Earith included Bluntisham and Colne are among the places near Earith, a village, that the same vans cover, throughout PE postcodes. Quickest of all: give a PE28 3 postcode for our van. There's no need to shift your car. Anywhere it stands — near Earith Village Hall, on a lay-by en route to Ouse Fen Nature Reserve, on a drive — that's where it is cleared. If you are close to a border, or somewhere hard to describe like the back of Air crash memorial, ring and ask rather than assuming. ## The short version for Earith motorists Pour no AdBlue until you have read the cap. AdBlue in the diesel tank regardless? Leave it switched off and ring 0333 366 0103; Petrol in Diesel empties it on the spot, throughout Cambridgeshire.