High Wycombe: 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 your motor and the ignition off then ring 0333 366 0103. A drain plus a full flush, carried out just where your car sits around High Wycombe, is normally all it takes when found before the motor runs. Not happened yet? Below, the page explains the reasons it happens and the ways to avoid it for good.
Why does AdBlue in a diesel vehicle need its own filler?
Plenty of newer diesels in Wycombe Marsh, like those in High Wycombe, carry on two fluids; the motor gets just your diesel. AdBlue goes to your exhaust, where it is sprayed into the gas to fresh it, and it lives in a tank of its own.
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. At the petrol pump, your diesel side is topped up constantly. Much less regularly, the AdBlue side is filled — normally from a bottle, by someone working out where it goes. Mistakes happen in that gap between them.
How does AdBlue in the diesel tank happen around High Wycombe?
Rarely is it carelessness: normally three things line up.
Hurry comes from the warning. The vehicle warns you as AdBlue runs low, and an empty tank puts it into limp mode — so the top-up gets done in a rush, before work on a driveway off Corporation Street, or heading home in the car park outside Three Tuns.
Then, your hand reaches for the cap it would have used on the old vehicle — since a rental car, a new vehicle or a company car puts the fillers where your last one did not.
A spouted bottle finds no resistance at a diesel filler no more than at an AdBlue one. And so the pour, once begun, keeps on. Cressex or the heart of High Wycombe: it is the same few seconds either way.
How to tell the AdBlue filler from the diesel one
A few seconds is all the checks take — so check them before you pour anything, on a drive in Sands or a forecourt in High Wycombe.
- Colour and lettering: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap usually does not. Go by the cap, not where it sits.
- On plenty of cars, size gives it away: AdBlue has the smaller filler neck.
- A label inside the fuel flap often says which fuel goes where, on many vehicles. Check for it.
- The handbook says which it is if the filler is not next to your diesel cap: the boot, or under the bonnet.
- Whoever had it before will know. Ask as you pick up a rental or fleet car — from the nearest station's car park, say — not once the warning appears.
Keeping AdBlue out of your diesel tank when you top up
Anywhere across Buckinghamshire the light comes on, this is a routine for that day.
- Not in a rush on the side of High Street, not on a slope, not with your engine running: park then switch off properly.
- Silly as it sounds, speaking "AdBlue" aloud while you unscrew the cap does the trick — once you've located your filler and read the cap.
- Leave the diesel cap on. If both sit under one flap, check the diesel cap is still closed before you lift the bottle.
- Stop once your tank fills or the bottle runs dry; before that, tip slowly using the built-in spout.
- Close the cap, then check once more — confirm your diesel cap remained shut the whole time. Only then, start the car.
If at step two or three you find you have already poured into the diesel side, stop there. Don't go on to step five.
Put AdBlue in your diesel tank around High Wycombe already?
Brief order, then. First: your engine remains unstarted. Do not switch your ignition on; on many diesels that alone runs the fuel pump. AdBlue does not mix with diesel — it sinks to the bottom of your tank, where your fuel is drawn from — so don't top up with diesel to dilute it.
Ask the staff to help push the car away from the petrol pump if you are on a forecourt — the Morrisons, the BP or anywhere else. Your own driveway around High Wycombe is where it stays.
If the engine has already run, stop as soon as it is safe then switch off. Leave the M40 — under a mile out of High Wycombe — at the first junction. A short hop across High Wycombe is a smaller job than a run towards St Albans, under 25 miles away, so tell us about how far it went.
Our arrival in High Wycombe, and what happens next
The van comes to the vehicle anywhere it stopped — your own driveway, near Red Lion, or outside Hamilton Academy. Our engineers ask what was put in, roughly how much, and if it's run, because those replies determine this work and the price. On the call itself, you hear the quote — before dispatch.
Emptying that tank comes next, then a full flush of the fuel system. Much more than with petrol, it matters with AdBlue: crystals build up, some metals are attacked, and none of that washes out unaided, no matter how long it sits. After the filter has been flushed — or replaced, if needed — fresh diesel is added, and then the car gets tested. Then our engineers start it and confirm it runs properly before we go.
Unstarted cars mostly need a half-hour visit after arrival. The equipment is safe on a live filling station, and hushed enough for a driveway after dark. Your insurer usually wants the engineer's report and the VAT invoice, and you get both at the end. Payment is on the day, with no deposit. It's worth checking your policy as the van travels to you: misfuelling cover comes with plenty of policies.
About High Wycombe
High Wycombe is a town in Buckinghamshire, situated near several lakes and the River Wye, at an elevation of around 73 metres. High Wycombe sits approximately 28 miles west of London and is close to nearby places such as Cressex, Terriers, and Micklefield. High Wycombe has a population of around 31,157 people and predominantly consists of flat-type housing. High Wycombe is also near the city of St Albans, which is about 19.5 miles away.
AdBlue drains around High Wycombe, and Buckinghamshire beyond
Terriers and Micklefield are among the towns around High Wycombe, a town, that the same teams cover, over HP postcodes. A postcode starting HP11 2 gets the van to you fastest.
Moving the car is not needed. Our engineers drain it where it is — a side street close to Wycombe Swan Theatre, a lay-by on the way to Margaret's Garden, a driveway. Ring and ask rather than guessing if you're near a boundary, or somewhere hard to explain, like the back of All Saints' Church.
High Wycombe drivers: the short version
Tip no AdBlue until you have read the cap. If AdBlue has gone in your diesel tank regardless, leave it off and phone 0333 366 0103. Petrol in Diesel clears it where it waits, anywhere in Buckinghamshire.