Preventing AdBlue in a Diesel Tank in Underhill: Why It Occurs
AdBlue already in your diesel tank? Then put this page aside for now, leave the ignition and engine off, then ring 0333 366 0103. In Underhill, finding it before the motor turns normally means a drain and a thorough flush on the spot. The rest of this page covers why it happens and how to ensure it does not — useful if you're reading before it has happened.
AdBlue in a diesel car, and its separate tank
Diesel goes to your motor — but plenty of newer diesels driven around Underhill and Hadley carry another liquid too. 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 motors the two sit side by side under the same flap; on others the AdBlue filler is in your boot or under the bonnet. At the petrol pump, the diesel side is topped up constantly. A driver who has to stop and work out where it goes normally fills the AdBlue side, from a bottle, and far less commonly. The mistake lives in that gap.
How AdBlue in your diesel tank takes place in Underhill
It is hardly ever carelessness. Three things tend to line up.
On a driveway off Elton Avenue before work, or in the car park at Queens Arms on the way home: that's where the rushed top-up happens. What is the reason for the rush? As AdBlue gets low your car warns you, and if it's empty, limp mode kicks in.
New-to-you motors come second, too. Hire cars, new cars and company vehicles put their fillers in new places, and the hand reaches for the cap it used on the old one.
Nothing halts the tip after it has started, since a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. The same few seconds decide it, in the middle of Underhill or out in Chipping Barnet.
Which filler is for AdBlue, and which for diesel?
Whether a Underhill forecourt or a drive out in Monken Hadley, take a couple of seconds on these before anything goes in.
- The cap. The AdBlue cap is often blue, or marked "AdBlue". Your diesel cap normally isn't. Read it instead of going by position.
- 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 is when the filler is not next to your diesel cap: the boot, or under the bonnet.
- Ask the person who drove it last — before you leave, not when the light comes on — when you pick up a hire or company car from somewhere like the car park outside New Barnet.
Topping up AdBlue without it reaching the diesel tank
Anywhere around Greater London the light comes on, here is a routine for the day.
- Park then switch off. Not on a slope, not with your engine running, and not in a rush on the side of Mays Lane.
- Locate the AdBlue filler, read the cap, and speak the word "AdBlue" out loud as unscrewing it. It sounds 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.
- Gently does it, through the bottle's own spout, till it's full or the bottle is empty.
- Shut the cap, then look once more — confirm the diesel filler stayed closed the whole time. Only then, start the car.
If at step two or three you find you have already poured into your diesel side, stop there. Leave out stage five entirely.
AdBlue in your diesel tank already, in Underhill?
The short order of things, beginning with no starting your engine. On many diesels your ignition alone runs the fuel pump, and so don't switch the car on. Thinning it with more diesel fails, since AdBlue sinks to the bottom instead of blending — and that's where your fuel is pulled from.
The staff at BP, Esso or another forecourt will usually help pushing the car clear if you ask. Your own driveway around Underhill is the place it should stay.
If the motor has already run, stop as soon as it is safe and switch off. Leave the M25 — under 3 miles out of Underhill — at the first exit. Tell us about how far it went: a run towards St Albans, under 10 miles away, is a bigger job than a short hop across Underhill.
What happens when our technicians get there in Underhill
Anywhere your car has stopped, whether outside St Catherine's RC School, beside Underhill Baptist Church or on your own drive, the van comes to it. Those replies settle the work and our price, so our engineers ask what was put in, about how much, and if it's run. During the phone call itself, you hear the quote — ahead of anything else.
The fuel system is then rinsed thoroughly, after the tank is emptied. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it doesn't wash out on its own. A test comes at the end: before that, fresh diesel is added, and the fuel filter is flushed or changed as needed. The engine is fired up next and checked to be sure it runs correctly, all before our technicians head off.
If the motor hasn't 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 in advance; you settle up on the day. At the end, a VAT invoice and the report from the engineer go to you for the insurer. Plenty of insurance policies include misfuelling cover, and so it's worth checking yours whilst we're on the way.
About Underhill itself
Underhill is a suburban area in Greater London, situated near the riverside and approximately 10 miles from central London. Underhill has a mix of semi-detached housing and is close to nearby places such as Chipping Barnet and New Barnet. Underhill sits at an elevation of around 94 metres, with St Albans being the nearest city at 9.5 miles away. Underhill is part of the larger London urban area, with a population of around 7824 residents.
AdBlue drains around Underhill and across Greater London
Underhill is a residential suburb, and our teams that cover it also work the towns around it, Ducks Island and New Barnet among them, across the EN postcode area. Quickest of all: quote a EN5 2 postcode to the van.
The vehicle doesn't need to shift. Anywhere it sits — beside The Rainbow Centre, in a lay-by en route to West Park, at home — that is where it is cleared. Awkward to explain, like the back of Hadley Wood Sports Trust? By a county line? Checking beats assuming, so ring.
Underhill motorists: the short version
Pour nothing until you've read the cap. Petrol in Diesel empties it on the spot, anywhere around Greater London, if AdBlue has gone in the diesel tank regardless — and so leave the vehicle off then phone 0333 366 0103.