Why It Happens and How to Avoid It: AdBlue in a Diesel Tank in Pen-sarn
Stop reading for a moment if the diesel tank already holds AdBlue in it: ignition off, motor off, and call 0333 366 0103. Normally, when your motor has not turned, it's drained and thoroughly rinsed where your car sits in Pen-sarn. The remainder of this page explains why it occurs and how to ensure it does not — handy if you are reading before it has happened.
AdBlue in a diesel motor: two tanks, two fillers
No single liquid but two: that is what plenty of newer diesels near Pen-sarn and Bolahaul Fm carry, with diesel feeding the motor. AdBlue's own tank keeps it, and from there it goes to your exhaust, and there a spray treats the fumes.
Different tanks, separate fillers. Under one flap, next to each other: that is the layout on many cars. On others, AdBlue's filler is beneath the bonnet or in the boot instead. At the pump, your diesel side gets filled constantly. The AdBlue side is topped up far less commonly, normally from a bottle, and normally by someone who has to stop and think where it goes. The mistake lives in that gap.
How does AdBlue in the diesel tank happen in Pen-sarn?
It's 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 — so a hurried top-up, perhaps before work off Roman Road, or outside The Caraway on the way home that evening.
Then the vehicle is strange. A hire car, a new vehicle or a company car puts the fillers where your last one did not, and your hand hits 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 pour once it has started. The same few seconds decide it, in the middle of Pen-sarn or out in Carmarthen.
Telling the AdBlue filler from your diesel filler
Check these first, on a forecourt around Pen-sarn or a driveway over in Johnstown. A few seconds, that's all.
- Blue and marking: an AdBlue cap is often blue, or says "AdBlue", where a diesel cap usually doesn't. Trust the cap, not where it sits.
- On plenty of cars, the size tells: AdBlue gets the smaller filler neck.
- A label inside your fuel flap often says which fuel goes where, on many vehicles. Look for it.
- The handbook. If the filler isn't by the diesel cap, it is in the boot or under the bonnet, and the handbook says which.
- The person who drove the car last. On a hire or company car collected from somewhere like the car park outside Carmarthen, ask before you leave, not when the light comes on.
Topping up AdBlue without it reaching the diesel tank
The day the light goes on, anywhere in Carmarthenshire, follow this routine.
- Park and switch off. Not on a slope, not with your engine running, and not in a rush on the side of Babell Hill.
- Find the AdBlue filler, read the cap, and say the word "AdBlue" aloud as unscrewing it. It seems silly. It does the trick.
- Leave your diesel cap on. If both sit under one flap, check your 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 runs out.
- Only after that, start the car: close the cap, check once more, and make sure the diesel cap was never opened.
If at stage two or three you find you have already poured into the diesel side, stop there. Stage five stays out.
Pen-sarn: already put AdBlue in your diesel tank?
The short order of things, starting with no starting the engine. The fuel pump starts on many diesels as soon as your ignition is switched on — and so leave it off. AdBlue doesn't mix with diesel — it sinks to the bottom of that tank, where your fuel is drawn from — so don't top up with diesel to thin it.
If you are on a forecourt, whether it's the Texaco or the Morrisons, ask the staff to help push the vehicle clear of the pump. At home in Pen-sarn? So the vehicle stays put.
If your motor has already run, stop as soon as it is safe then switch off. Pen-sarn lies under 15 miles from the M4; on it, use the first exit. A short hop across Pen-sarn is a smaller job than a run towards Swansea, under 25 miles away, and so tell us about how far it went.
When we arrive around Pen-sarn, what occurs?
Our engineers come to the car wherever it has stopped, whether that's outside the local primary school, close to Babell Zion Newydd or on your own driveway. The answers settle the work and the quote, so we ask what got in, roughly how much, and whether it's run. During the call itself, you hear the price — before anything else.
The system is then flushed thoroughly, after the tank is emptied. More than with petrol, it matters with AdBlue: the crystals build up, some metals corrode, and none of that washes away unaided, no matter how long it is left. After your filter is cleaned — or renewed, if required — fresh diesel is added, and finally the car is tested. After that our engineers fire it up and make sure it runs smoothly before we go.
Most jobs are done in about half an hour once our engineers arrive, as long as the engine has not run — and the pumps our technicians use are fine on a live forecourt and quiet at night outside a house. Paying happens on the day, not upfront, and you are given the documents an insurer wants: an engineer's report and a VAT invoice. Many insurance policies include misfuelling cover, so it is worth checking yours while we're on the way.
About Pen-sarn and where it is
Pen-sarn is a suburban area in Carmarthenshire, situated on the riverside at an elevation of 21 metres. Pen-sarn lies near the towns of Carmarthen and Tre-gynwr, and is within commuting distance of Swansea, which is 22 miles away. Pen-sarn has a population of around 1411 people and is characterised by detached housing.
AdBlue drains in Pen-sarn and across Carmarthenshire
Tre-gynwr and Pibwrlwyd are among the towns around Pen-sarn, a residential suburb, that the same vans cover, over SA postcodes. Quote a postcode beginning SA31 2, and the van gets there quickest.
The car stays put. We drain it where it is — a side street near Oak Leaves, a lay-by on the way to Llangunnor Community Park, a driveway. Ring and ask instead of guessing if you're near a boundary, or somewhere hard to explain, like the back of The Carmarthen Dragon.
For Pen-sarn motorists, the short version
Before you pour, read the cap. Even so AdBlue in the diesel tank? Petrol in Diesel can empty it wherever it stands, anywhere in Carmarthenshire: keep it off and phone 0333 366 0103.