Why It Happens and How to Avoid It: AdBlue in a Diesel Tank in Blackweir
Stop reading a minute when the diesel tank already holds AdBlue in it: ignition off, motor off, then phone 0333 366 0103. Caught before the motor runs, it is usually a drain and a thorough flush, done where your car is in Blackweir. The rest of this page covers why it happens and how to ensure it does not — handy if you are reading ahead of time.
Why does AdBlue in a diesel motor need its own filler?
Plenty of newer diesels on the roads around Blackweir and Pontcanna carry two liquids, not one. Diesel goes to your motor. Your exhaust, not your engine, is where AdBlue goes: dosed into the fumes to fresh them, from a separate tank.
Every tank has a filler of its own. Many of cars share a single flap for the two, whereas some move the AdBlue filler to the boot or under the bonnet. Diesel goes in on every filling station call-out, week in, week out. Much less often, the AdBlue side gets filled — normally from a bottle, by someone thinking about where it goes. The mistake lives in that gap.
How AdBlue in the diesel tank takes place in Blackweir
It is hardly ever carelessness. Three things tend to line up.
On a drive off Colum Road before work, or in the car park outside The Blackweir Tavern on the way home: that is where the hurried top-up takes place. What is the reason for the rush? As AdBlue runs low the car warns you, and once it's gone, limp mode follows.
Then your car is new. A hire car, a new vehicle or a company car puts the fillers where your last one did not, and your hand reaches 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, and so nothing stops the pour once it has started. It takes a few seconds, whether out in Cathays or right in the heart of Blackweir.
Which filler is for AdBlue, and which for diesel?
Whether a Blackweir forecourt or a driveway over in Central, take a few seconds on these before anything is poured in.
- Where it sits can mislead; the cap doesn't. AdBlue ones tend to be blue or carry the word "AdBlue" — diesel ones usually don't.
- The size. On many motors the AdBlue filler neck is the smaller of the two.
- Check inside the fuel flap: many cars have a label there showing which fuel goes where.
- The handbook. If your filler is not by your diesel cap, it is in your boot or under the bonnet, and the handbook says which.
- The previous driver will know. Ask as you collect a hire car or company car — from Cathays's car park, say — not when the light appears.
Keeping AdBlue out of your diesel tank when you top up
On the day the warning comes on — wherever it is around Cardiff — a simple routine to use.
- Park and switch off. Not on a slope, not with the engine running, and not in a rush on the side of Colum Place.
- Daft as it sounds, saying "AdBlue" out loud as you unscrew the cap does the trick — after you have found the filler and read it.
- The diesel cap stays on. When the two share a flap, make sure it is shut before lifting the bottle.
- Using the bottle's own spout, pour slowly — and stop when it's full or the bottle is empty.
- Shut the cap, then look again — confirm the diesel cap stayed shut the whole time. Only then, start your car.
Find at step two or three that it's already gone into your diesel side? So stop just there. Never go on to stage five.
Already put AdBlue in the diesel tank around Blackweir?
Short list, then. First: your motor stays off. Leave your ignition off too, since on plenty of diesels switching it on by itself runs the fuel pump. AdBlue doesn't mix with diesel — it sinks to the bottom of that tank, where the fuel is sucked from — so don't top up with diesel to thin it.
On a forecourt — Texaco, Esso or another — the attendants will normally help roll the vehicle clear, if you ask. Leave it where it is if you are on your own drive in Blackweir.
Stop as soon as it is safe then switch off, if your engine has already run. On the M4, under 5 miles from Blackweir, that means the next exit. Tell us about how far it went: a run towards Cardiff, under 3 miles away, is a bigger job than a short hop across Blackweir.
Our arrival around Blackweir, and what happens next
Anywhere the vehicle came to rest, be it by the local primary school, beside Bethel United Church of Jesus Christ or at home, our van comes to it. Those replies settle this work and our price, and so we ask what was put in, about how much, and if it's run. You hear that price on the phone, before anyone heads out.
After that: draining, then a full flush of the whole system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, so it doesn't wash out on its own — which is why that counts more with AdBlue than with petrol. After the filter is flushed — or replaced, if needed — fresh diesel goes in, and finally the car is tested. The engine is started next and tested to confirm it runs correctly, all before our engineers leave.
If your engine 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 at night. The insurer usually wants the engineer's report and your VAT invoice, and you get both at the end. Payment comes on the day, with no deposit. Misfuelling cover is part of many insurance policies — and so use the wait to look at yours.
About Blackweir
Blackweir is a suburban area in Cardiff, situated near the coast and approximately 1 mile from the city centre. Blackweir has a mix of housing types, but is predominantly characterised by terraced homes. Blackweir is close to nearby places such as Cathays, Maindy, and Cathays Park, and is part of the larger Cardiff urban area.
AdBlue drains across Cardiff, Blackweir included
Over CF postcodes, our teams that cover Blackweir — a residential suburb — work the nearby places too, Cathays Park and Maindy among them. Our van gets to you fastest with a postcode starting CF10 3.
The car doesn't need to move. A driveway, a lay-by on the way to Blackweir Fields, a side street close to Christian Science Church: our technicians drain it where it is. Guessing doesn't help behind Cardiff International Church, on a border, or somewhere awkward to pin down; ring and check.
Blackweir motorists: the short version
Before you pour, read the cap. Petrol in Diesel drains it on the spot, anywhere around Cardiff, if AdBlue has gone in the diesel tank regardless — and so leave the vehicle off then phone 0333 366 0103.