--- title: Fen Ditton: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/fen-ditton-cambridgeshire/ location: Fen Ditton county: Cambridgeshire latitude: 52.221180 longitude: 0.169780 service: AdBlue in a Diesel Tank updated: 2026-10-05 --- # Fen Ditton: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? Leave your engine and ignition off then phone 0333 366 0103 now — the rest can wait when AdBlue is already in the diesel tank. Around Fen Ditton, finding it before your motor runs normally means a drain and a thorough flush where it stands. The remainder of this page covers why it happens and how to make sure it does not — useful if you are reading before it has happened. ## AdBlue in a diesel motor: two tanks, two fillers No single liquid but two: that is how many newer diesels around Fen Ditton and Teversham carry, with diesel feeding your engine. AdBlue's own tank holds it, and from there it is sent to your exhaust, where spraying cleans the gas. Different tanks, different fillers. Plenty of motors share a single flap for both, whereas some put the AdBlue filler to the boot or under the bonnet. Diesel gets filled at every filling station visit, again and again. Someone who has to stop and think where it goes usually fills the AdBlue side, from a bottle, and much less regularly. That gap is where the mistake lives. ## How does AdBlue in the diesel tank occur in Fen Ditton? It is seldom carelessness. Three things tend to line up. Haste follows from the warning. Your car warns you as AdBlue runs low, and a dry tank sends it into limp mode — so the top-up happens in a rush, before work on a driveway off Church Street, or heading home in the car park outside Kings Head. Then, your hand reaches for the cap it would have used on the old motor — because a hire car, a new motor or a company car puts the fillers where your last one didn't. A spouted bottle meets no resistance at a diesel filler any more than at an AdBlue one. And so the pour, after started, keeps on. Chesterton or the heart of Fen Ditton: it takes the same few seconds either way. ## The AdBlue filler and your diesel filler: telling them apart A couple of seconds is all these take — so run through them before you pour anything, on a driveway in Horningsea or a forecourt around Fen Ditton. - Where it sits misleads; the cap does not. AdBlue ones tend to be blue or bear the word "AdBlue" — diesel ones normally don't. - Look at the size: the smaller filler neck is, on many cars, the AdBlue one. - A label inside the fuel flap frequently says which fuel goes where, on plenty of vehicles. Check for it. - Can't see it beside the diesel filler? Then check beneath the bonnet or in the boot — the owner's manual will say which. - Picking up a hire or company car, perhaps at the car park at Cambridge North? Check with the person who drove it last before leaving, rather than once the light comes on. ## Keeping AdBlue out of the diesel tank when you top up Wherever in Cambridgeshire the light comes on, this is a routine for that day. - Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of Fen Ditton High Street. - Say "AdBlue" out loud as you unscrew the cap, once you find the AdBlue filler and reading it. Daft, yes, but it works. - If both sit under one flap, check the diesel cap is still closed before you lift the bottle — then leave the car on. - Finish when the tank fills or the bottle is empty; before that, pour gently through its built-in spout. - Before starting your car, close the cap and check again that the diesel cap never opened off. Spot at step two or three that it has already gone into the diesel side? Then stop right there. Never carry on to stage five. ## Put AdBlue in the diesel tank around Fen Ditton already? The short order of things, beginning with not starting the engine. Do not switch your ignition on; on plenty of diesels that alone runs the fuel pump. Topping up with diesel will not dilute it: rather than mixing, AdBlue drops to the bottom of that tank, just where fuel is drawn from. The attendants at BP, Camgas or another forecourt will usually help to push the car away when asked. Leave it where it is if you're on your own drive around Fen Ditton. When the motor has run by now, pull over somewhere safe and turn the car off. On the M11, under 5 miles from Fen Ditton, that means the next exit. A short hop across Fen Ditton is a smaller job than a run towards Cambridge, under 3 miles away, and so tell us roughly how far it went. ## Fen Ditton: what happens when our technicians get there By Fen Ditton Primary School, near St Mary the Virgin or on your own driveway: wherever the car has stopped, we come to it. Both the work and our quote depend on three answers — which fluid, what quantity, and whether it's run — so our engineers ask. That price is given on the call, ahead of any van leaving. Draining the tank comes next, followed by a full flush of the fuel system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, so it doesn't wash out on its own — which is why that matters more with AdBlue than with petrol. The fuel filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and the car is tested. After that we fire it up and make sure it runs smoothly before we go. If your engine has not run, most jobs take about half an hour once we're there, using pumps that are safe on a working forecourt and quiet enough to use outside a house after dark. No money upfront; you settle up that day. Afterwards, the VAT invoice and the report from the engineer are handed to you for your insurer. Wrong-fuel cover is part of many insurance policies — so make use of the wait to look at yours. ## About Fen Ditton Fen Ditton is a small village in Cambridgeshire, situated on the River Cam and close to the city of Cambridge. Fen Ditton has a low elevation of around 17 metres and is surrounded by nearby places such as Chesterton and Coldhams Common. Fen Ditton remains a quiet residential community with a mix of housing types, including semi-detached homes. Fen Ditton is located approximately 50.9 miles from London, making it a commuter village with easy access to the capital. ## AdBlue drains around Fen Ditton and across Cambridgeshire Being a village, Fen Ditton shares its vans surrounding places — Coldhams Common, Quy Waters — all the way through CB postcodes and the surrounding area beyond. A postcode starting CB5 8 gets the van to you fastest. Shifting your car is not needed. Draining happens right there, be it a drive, a street by Fen Ditton Village Hall, or a lay-by towards Fen Ditton Recreation Ground. If you're near a border, or somewhere hard to explain like the back of Fen Ditton Village Sign, ring and ask rather than guessing. ## For Fen Ditton motorists, the short version First, the cap; after that, the tip. Even so AdBlue in the diesel tank? Petrol in Diesel can empty it where it is, anywhere around Cambridgeshire: switch the vehicle off then ring 0333 366 0103.