How It Happens and How to Prevent It: AdBlue in a Diesel Tank in Pen-y-garn
Stop here for a moment when the diesel tank already has AdBlue in it: ignition off, motor off, and phone 0333 366 0103. Around Pen-y-garn, finding it before the motor runs normally leaves draining and a thorough flush where it stands. The remainder of this page explains why it happens and how to make sure it does not — handy if you're reading before it has happened.
AdBlue in a diesel vehicle: two tanks, two fillers
Not one liquid but two: that's how plenty of newer diesels around Pen-y-garn and Capel Llanilltern run, with diesel feeding the motor. Kept in a tank of its own, AdBlue is fed into the exhaust gas and cleans it.
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 pump, your diesel side is topped up constantly. Someone who has to stop and think where it goes normally fills the AdBlue side, from a bottle, and far less often. That gap is where the mistake lives.
Pen-y-garn: how AdBlue in the diesel tank takes place
Three things tend to line up, and carelessness is rarely one of them.
On a driveway off Pen Y Waun before work, or in the car park at The Lewis Arms heading home: that's where the hurried top-up takes place. What is the reason for the rush? As AdBlue gets low the vehicle tells you, and if it is empty, limp mode kicks in.
Then the vehicle is unfamiliar. A hire car, a new car or a company car puts the fillers where your last one did not, and your hand gets to for the cap it would have used on the old one.
Third, the bottle fits: diesel filler or AdBlue one, it slides in as easily, and after the tip begins, no part stops it. The same few seconds settle it, in the middle of Pen-y-garn or out in Soar.
Which filler is for AdBlue, and which for diesel?
Whether a Pen-y-garn forecourt or a driveway over in Gwaelod-y-garth, spend a couple of seconds on these before anything goes in.
- Position can mislead; the cap does not. AdBlue ones are often blue or bear the name "AdBlue" — diesel ones usually do not.
- Check the size: the smaller filler neck is, on many motors, the AdBlue one.
- A label inside the fuel flap often shows which fuel goes where, on plenty of cars. Check for it.
- In your boot or under the bonnet: that's where the filler is if it is not by the diesel cap, and the handbook tells you which.
- The person who drove the car last. On a hire or company car collected from somewhere like the car park at Taffs Well, ask before you leave, not when the light comes on.
How to top up without AdBlue in the diesel tank
On the day the warning comes on — wherever you are across Cardiff — a routine to use.
- Switch off once parked — level ground, motor stopped, and never in a rush by Maes Y Sarn on the verge.
- Find the AdBlue filler, read the cap, and say the name "AdBlue" aloud as unscrewing it. It sounds silly. It works.
- The diesel cap remains on. When both sit under a flap, make sure it's shut before lifting the bottle.
- Tip slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty.
- Only after that, start the vehicle: close the cap, check once more, and make sure your diesel cap was never opened.
Find at step two or three that it's already gone into the diesel side? So stop right there. Stage five is off limits.
Pen-y-garn: already put AdBlue in your diesel tank?
Short list, then. Top of that: the engine stays off. The fuel pump runs on many diesels as soon as the ignition goes on — and so keep it off. AdBlue does not mix with diesel — it sinks to the bottom of that tank, where the fuel is pulled from — so do not top up with diesel to dilute it.
If you're at a forecourt, whether it is the BP or the Texaco, ask the staff to help roll the car clear of the pump. At home around Pen-y-garn? Then your car remains where it is.
If your motor has already run, stop as soon as it is safe and switch off. Leave the M4 — under 3 miles out of Pen-y-garn — at the first exit. Tell us about how far it went: a run towards Cardiff, under 10 miles away, is a bigger job than a short hop across Pen-y-garn.
Pen-y-garn: what takes place when our engineers arrive
Anywhere your car has stopped, whether by the local primary school, near St. Catwg's or at home, our van travels to it. What fluid got in, the quantity, and if it ran: we ask because those answers set both work and price. You get that price on the phone, before anybody sets off.
Next: draining, then a full flush of the entire system. More than with petrol, it matters with AdBlue: crystals form, certain metals are attacked, and none of that clears away on its own, no matter how long it sits. Testing is last: before that, fresh diesel goes in, and the fuel filter is flushed or changed as needed. After that we fire it up and check it runs properly before we leave.
Most jobs are finished in roughly half an hour once our engineers get there, provided your engine hasn't run — and the pumps our technicians use are safe on a busy forecourt yet quiet after dark beside a house. Payment is on the day, not upfront, and you are given the paperwork an insurer asks for: an engineer report and a VAT invoice. Plenty of insurance policies include misfuelling cover, and so it's worth checking yours whilst we are on the way.
About Pen-y-garn and where it is
Pen-y-garn is a suburban area located inland, approximately 6.4 miles north of Cardiff, with an elevation of around 171 metres. Pen-y-garn sits near the communities of Soar, Pentyrch, and Creigiau, and is characterized by its predominantly detached housing stock. Pen-y-garn is a relatively small community, with a population of around 1738 residents. Pen-y-garn is situated in a convenient location, with Cardiff to the south and the Welsh countryside to the north.
AdBlue drains across Cardiff, Pen-y-garn included
Pentyrch and Creigiau are among the places near Pen-y-garn, a residential suburb, that the same vans cover, throughout CF postcodes. Our van reaches you fastest with a postcode starting CF15 9.
The car remains where it is. A drive, a lay-by on the way to Memorial Park, a side street close to Llan Colliery: we drain the car where it is. Tricky to explain, like the back of Gwaelod-Y-Garth Village Hall? By a border? Checking is better than guessing, and so phone.
Pen-y-garn motorists: the short version
Tip nothing till you've read the cap. If AdBlue has gone in the diesel tank all the same, leave the vehicle off then ring 0333 366 0103. Petrol in Diesel clears it where it sits, anywhere in Cardiff.