The Knab: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It?
If AdBlue is already in your diesel tank, stop reading for a moment: leave your engine and the ignition off and call 0333 366 0103. Caught before your motor runs, it's normally a drain and a thorough flush, done where the car is in The Knab. Not happened yet? Further down, the rest of the page covers the why it occurs and the ways to avoid it for good.
Two fillers, two tanks: AdBlue in a diesel motor
Diesel goes to your engine — but plenty of newer diesels driven round The Knab and Mumbles hold another liquid as well. Kept in a tank of its own, AdBlue is fed into your exhaust gas and cleans it.
Each tank has its own filler. Under one flap, side by side: that is the layout on a lot of vehicles. Elsewhere, AdBlue's filler sits beneath the bonnet or in your boot instead. Diesel goes in on each forecourt visit, again and again. Someone who has to stop and work out where it goes usually tops up the AdBlue side, from a bottle, and much less regularly. That gap is where the error lives.
How does AdBlue in the diesel tank take place in The Knab?
Three things tend to come together, and carelessness is rarely one of them.
On a driveway off Mumbles Road before work, or in the car park at The Pilot on the way home: that is where the hurried top-up takes place. What is the reason for the rush? As AdBlue gets low the car tells you, and once it is gone, limp mode kicks in.
Then, the hand goes for the cap it would have used on the old vehicle — because a hire car, a new car or a company car places the fillers where your last one did not.
A spout-topped bottle finds no resistance at a diesel filler no more than at an AdBlue one. And so the pour, after started, carries on. Mumbles Hill or the middle of The Knab: it takes the same few seconds either way.
How to tell the AdBlue filler from the diesel one
Look at these first, at a forecourt in The Knab or a drive out in Oystermouth. A few seconds, that's all.
- The cap. The AdBlue cap is often blue, or marked "AdBlue". Your diesel cap usually is not. Read it rather than going by position.
- Check the size: the smaller neck is, on many motors, the AdBlue one.
- Open the flap and check for a label — plenty of motors show which goes in each inlet just there.
- The handbook. If the filler isn't by the diesel cap, it's in your boot or under the bonnet, and the handbook says which.
- Picking up a hire or company car, say at the car park outside Swansea? Ask the person who drove the vehicle last before you set off, rather than once the light goes on.
How to top up without AdBlue in the diesel tank
Wherever around Swansea the light comes on, here is a routine for that day.
- Park then switch off. Not on a slope, not with the motor running, and not in a rush on the side of Clifton Terrace.
- Locate the AdBlue filler, read the cap, and say the name "AdBlue" out loud as unscrewing it. It seems silly. It does the trick.
- Leave the 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, until it's full or the bottle is empty.
- Close the cap and check again. Make sure the diesel cap was never opened. Only then start the car.
Stop there if you find, at stage two or three, that you've already poured into the diesel side. Don't carry on to stage five.
AdBlue in your diesel tank already, in The Knab?
Don't start the engine: that's where the short order of things begins. Leave your ignition off too, since on plenty of diesels switching it on alone starts your fuel pump. Do not top up with diesel to dilute it: AdBlue doesn't mix with diesel, it sinks to the bottom of that tank, where the fuel is drawn from.
If you're on a forecourt, whether it's the Newton Garage or the Texaco, ask the staff to help push the vehicle away from the petrol pump. Leave it where it is if you're on your own driveway around The Knab.
Already run? Pull over when it is sensible, then switch off. Leave the M4 — under 10 miles out of The Knab — at the first exit. Tell us about how far it went: a run towards Swansea, under 5 miles away, is a bigger job than a short hop across The Knab.
What happens when our engineers arrive around The Knab
We come to the car wherever it has stopped, whether that's outside the local primary school, close to Limeslade Beach or on your own driveway. Both the work and our quote depend on three answers — what liquid, which quantity, and if it has run — so our technicians ask. On the call itself, you hear our price — ahead of anything else.
The fuel system is then rinsed thoroughly, once the tank is drained. 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 matters more here than with petrol. Your filter is flushed, or replaced where it needs to be; clean diesel goes in; and your car is tested. Before we go, we start the engine and confirm that it is running properly.
With pumps fine on a working forecourt and quiet enough for use outside a house at night, most jobs in which your motor hasn't run take about half an hour once our engineers arrive. 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 policy while we travel to you: misfuelling cover comes with plenty of policies.
About The Knab, for a moment
The Knab is a coastal locality in Swansea, situated near Mumbles Hill and overlooking the Bristol Channel. The Knab sits at an elevation of 71 metres, with detached housing being the predominant type of accommodation in the area. The Knab is close to nearby places such as Limeslade and Thistleboon, and is approximately 4 miles from the city of Swansea.
AdBlue drains around The Knab and across Swansea
The Knab is a coastal area, and our vans that cover it also work the towns near it, Limeslade and Thistleboon among them, across the SA postcode area. Give a postcode beginning SA3 4, and the van gets there fastest.
No need to move the vehicle. Our engineers drain it where it is — a side street near The Big Apple, a lay-by on the way to Mumbles Hill Nature Reserve, a driveway. Guessing doesn't help behind Bracelet Bay, on a boundary, or anywhere hard to describe; ring and check.
In short, for The Knab people
Read the cap before you tip. If AdBlue has gone in your diesel tank all the same, leave it off and call 0333 366 0103. Petrol in Diesel drains it where it waits, anywhere around Swansea.