How It Happens and How to Avoid It: AdBlue in a Diesel Tank in Tywyn
If AdBlue is already in your diesel tank, stop reading for a moment: leave the engine and the ignition off then phone 0333 366 0103. A drain and a thorough flush, done right where the car sits in Tywyn, is usually what it needs if found before your engine runs. Not happened yet? Further down, the rest of the page explains the reasons it occurs and the ways to prevent it altogether.
Two fillers, two tanks: AdBlue in a diesel car
Plenty of newer diesels around Bryncrug, like those in Tywyn, run on two liquids; the motor gets just your diesel. Your exhaust, not the engine, is where AdBlue ends up: dosed into the gas to fresh it, from its own tank.
Different tanks, separate fillers. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. Topping up your diesel side at the pump goes on constantly. Far less frequently, the AdBlue side gets topped up — mostly from a bottle, by someone thinking about where it goes. That gap is where the slip lives.
How does AdBlue in the diesel tank occur around Tywyn?
Carelessness rarely causes it. Instead is three things coming up together.
Hurry follows from the warning. The vehicle tells you as AdBlue runs low, and a dry tank sends the vehicle into limp mode — so the top-up gets done in a rush, before work on a driveway off Ffynnon Arian, or heading home in the car park outside Tredegar Arms.
The old car's cap is where your hand reaches — yet a rental car, a new vehicle or a company car puts the fillers somewhere else. That's the second factor: an unfamiliar motor.
A spout-topped bottle meets no obstacle at a diesel filler any more than at an AdBlue one. So the tip, once started, keeps on. It takes a few seconds, whether in Pendre or right in the centre of Tywyn.
The AdBlue filler and the diesel filler: telling them apart
A few seconds is all these take — so check them before you tip anything, on a drive in Tonfanau or a forecourt around Tywyn.
- Blue and marking: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap usually does not. Go by the cap, not where it sits.
- Check the size: the smaller neck is, on plenty of cars, the AdBlue one.
- Open the flap and check for a label — many vehicles show which goes in which filler right there.
- Can't see it beside the diesel filler? In that case look below the bonnet or inside the boot — the handbook says which.
- Check with the person who drove it last — before you leave, not when the light comes on — if you pick up a hire or company car from somewhere like the car park at the nearest station.
Keeping AdBlue out of your diesel tank when you top up
A routine for the day the light comes on, wherever around Gwynedd that is.
- Turn off after you park — flat ground, motor off, and never in a rush beside High Street at the roadside.
- Daft as it sounds, saying "AdBlue" aloud as you unscrew the cap does the trick — after you've located the filler and read the cap.
- The diesel cap stays on. Where both share a flap, make sure it's closed before the bottle comes up.
- Gently is best, through the bottle's own spout, till it is full or the bottle runs out.
- Close the cap and check once more. Make sure your diesel cap was never opened. Only then start the car.
Find at stage two or three that it's already gone into your diesel side? Then stop just there. Skip step five entirely.
Already put AdBlue in your diesel tank in Tywyn?
Short list, then. First: the motor stays unstarted. The fuel pump runs on plenty of diesels the moment the ignition is switched on — so leave it off. Diluting it with more diesel fails, because AdBlue sinks to the bottom rather than blending — and that is where the fuel is pulled from.
The attendants at Essar, another forecourt nearby or another forecourt will usually lend a hand to push the car away when asked. Your own driveway in Tywyn is where it should stay.
If your engine has already run, stop as soon as it is safe and switch off. On the M4, over 50 miles from Tywyn, that means the next junction. Mileage matters — a short hop across Tywyn makes a smaller job than driving under 50 miles towards Bangor — so say about how far it went.
Tywyn: what happens when our engineers turn up
Our van reaches the vehicle wherever it stopped — your own drive, beside Tywyn Baptist Church, or outside the local primary school. Our engineers ask what got in, about how much, and if it's run, since the answers determine the work and our quote. That quote is given over the phone, ahead of any van leaving.
The fuel system is then purged thoroughly, once the tank is cleared. AdBlue crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own — which is why that counts more with AdBlue than with petrol. Filter flushed or, where needed, swapped; clean diesel in; then a test of your vehicle. The motor is started next and tested to make sure it runs properly, all before we head off.
Most jobs are done in about half an hour once we arrive, provided your engine hasn't run — and the pumps we use are fine on a busy forecourt and quiet after dark outside a house. Payment is on the day, not upfront, and you are given the documents your insurer asks for: an engineer report and a VAT invoice. While we travel, take a look at your insurance documents; many include cover for misfuelling.
About Tywyn
Tywyn is a coastal town in Gwynedd, Wales, situated on the Cardigan Bay coast at a low elevation of around 8 metres. Tywyn has a mix of housing types, but detached homes are particularly prevalent, and the town is surrounded by smaller communities like Pendre and Bryn-y-mor. Tywyn is located near the mouth of the River Dysynni and is a popular base for exploring the surrounding Welsh countryside. Tywyn remains a small but distinct town with its own character and community.
Tywyn and Gwynedd: AdBlue drains across the area
Throughout LL postcodes, the teams that cover Tywyn — a coastal town — work the surrounding spots too, Rhyd-yr-onen and Bryn-y-mor included. Our van reaches you fastest with a postcode starting LL36 9.
The vehicle remains where it is. We drain it where it is — a side street near Canolfan Hamdden Bro Dysynni, a lay-by on the way to Tywyn Fruit Tree Conservation Park, a driveway. Guessing doesn't help behind Llyfrgell Tywyn, close to a boundary, or anywhere awkward to pin down; phone and ask.
In short, for Tywyn motorists
Pour no AdBlue until you've read the cap. Still AdBlue in your diesel tank? Petrol in Diesel can drain it wherever it stands, anywhere in Gwynedd: keep it off and phone 0333 366 0103.