How It Happens and How to Prevent It: AdBlue in a Diesel Tank in Gilwern
Keep your motor and ignition off then ring 0333 366 0103 now — reading can wait if AdBlue is already in the diesel tank. Caught before your motor runs, it's usually a drain and a thorough flush, done where the car is in Gilwern. If you're reading before it has happened, the rest of this page is about why it takes place and how to make sure it does not.
Two fillers, two tanks: AdBlue in a diesel motor
Diesel feeds your engine — yet many modern diesels seen about Gilwern and Twyn Wenallt carry another fluid too. Its own tank keeps it, and from there it goes to the exhaust, and there spraying treats the gas.
Separate tanks, separate fillers. Under one flap, next to each other: that's the layout on many vehicles. Elsewhere, AdBlue's filler sits under the bonnet or in the boot instead. Topping up the diesel side at the pump happens constantly. A driver who has to stop and work out where it goes usually fills the AdBlue side, from a bottle, and much less regularly. That gap is where the error lives.
AdBlue in the diesel tank in Gilwern: how it happens
It is rarely carelessness. Three things tend to line up.
First, the warning. Low AdBlue brings a warning from the vehicle, and running dry means limp mode — hence a rushed top-up, perhaps before work off A4077, perhaps outside The Beaufort on the way home after work.
Then the vehicle is strange. A hire car, a new motor or a company car puts the fillers where your last one did not, and the hand hits for the cap it would have used on the old one.
A spout-topped bottle meets no resistance at a diesel filler any more than at an AdBlue one. And so the tip, once started, carries on. It takes a few seconds, be it in Upper Common or right in the heart of Gilwern.
The AdBlue filler and the diesel filler: telling them apart
Check these first, at a forecourt in Gilwern or a driveway out in Tyla. A few seconds, that's all.
- Check the cap instead of going by where it sits: AdBlue caps are frequently blue or marked "AdBlue", and diesel ones normally are not.
- Look at the size: the smaller neck is, on many vehicles, the AdBlue one.
- A label inside the fuel flap frequently says which fuel goes where, on many vehicles. Look for it.
- In the boot or under the bonnet: that is where the filler sits if it is not by your diesel cap, and the handbook says which.
- The previous driver will know. Ask as you pick up a hire car or company car — at Abergavenny's car park, say — not once the warning appears.
AdBlue top-ups that never reach the diesel tank
The day the light goes on, wherever in Monmouthshire, use this routine.
- Stop somewhere level, motor off, with time in hand — not rushing on the side of Main Road.
- Locate the AdBlue filler, read the cap, and say the word "AdBlue" out loud as you unscrew it. It seems daft. It works.
- The two behind one flap? Then make sure the lid on the diesel filler stays shut ahead of raising the bottle.
- Stop when that tank fills or the bottle runs dry; until then, tip slowly through its built-in spout.
- Close the cap and check again. Make sure your diesel cap was never opened. Only then start the car.
Discover at the second or third stage that AdBlue went into the diesel filler? That's where you stop. Step five stays out.
Gilwern: already put AdBlue in your diesel tank?
Short list, then. First: your motor stays unstarted. The fuel pump starts on plenty of diesels the moment the ignition goes on — so keep it off. Filling up with diesel won't dilute it: rather than mixing, AdBlue drops to the bottom of that tank, just where fuel is taken from.
If you're on a forecourt, whether it is the Gulf or the BP, ask the staff to help push your car clear of the petrol pump. If you are on your own driveway around Gilwern, leave it where it is.
Already started? Stop when it's safe, then turn off. The next junction means where to leave if you're on the M4, under 25 miles from Gilwern. Roughly how far did it go? Crossing Gilwern is smaller work than a trip of under 25 miles to Newport, so say.
Gilwern: what takes place when our technicians turn up
The van reaches the vehicle anywhere it has come to rest — your own driveway, beside Crawshay Memorial, or outside the local primary school. Those answers decide this work and the price, so our engineers ask what went in, about how much, and whether it's run. You hear that price on the phone, before anybody heads out.
Draining your tank comes next, then a thorough flush of the fuel system. More than with petrol, it counts with AdBlue: the crystals form, some metals corrode, and none of that clears out unaided, no matter how long it sits. The filter flushed or, where needed, replaced; clean diesel in; then a test of your car. The engine is fired up next and tested to make sure it runs properly, all before our technicians head off.
If your motor hasn't run, most jobs take about half an hour once we're there, using pumps that are fine on a working forecourt and quiet enough to use outside a house after dark. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. It's worth looking at your insurance as the van travels to you: misfuelling cover comes with plenty of policies.
About Gilwern itself
Gilwern is a village situated on the banks of the River Usk in Monmouthshire, with a mix of rural and riverside landscapes. Gilwern has a population of around 1629 people and is characterised by predominantly detached housing. Gilwern is located near several smaller communities, including Upper Common, Pen-y-bont, and Lower Common, and is approximately 16.9 miles from Newport. Gilwern sits at an elevation of 103 metres above sea level, in a scenic area of south Wales.
AdBlue drains around Gilwern and across Monmouthshire
Gilwern is a village, and the teams that cover it also work the towns near it, Pen-y-bont and Lower Common among them, across the NP postcode area. A postcode starting NP7 0 gets the van to you fastest.
Shifting your car isn't necessary. Draining happens right there, be it a driveway, a road by Gilwern War Memorial, or a layby on the way to Garden of Remembrance. Ring and ask instead of assuming if you're close to a boundary, or somewhere hard to explain, like the back of Garden of Remembrance.
For Gilwern drivers, the short version
Tip no AdBlue till you have read the cap. AdBlue in the diesel tank after all? Leave the vehicle off then ring 0333 366 0103; Petrol in Diesel empties it where it stands, across Monmouthshire.