Avoiding AdBlue in a Diesel Tank in Trevithal: Why It Happens
If AdBlue is already in your diesel tank, stop reading for a moment: leave your motor and the ignition off then phone 0333 366 0103. In Trevithal, catching it before the engine turns normally means a drain and a thorough flush where it stands. The rest of this page explains why it happens and how to make sure it doesn't — useful if you are reading before it has happened.
Why does AdBlue in a diesel car need its own filler?
Diesel feeds your engine — but plenty of modern diesels driven around Trevithal and Raginnis hold a second liquid as well. The exhaust, not your engine, is where AdBlue goes: sprayed into the gas to clean them, from a separate tank.
Each tank comes with a filler of its own. Many of motors share a single flap for both, whereas others put the AdBlue filler to the boot or under the bonnet. The diesel side is topped up at the pump all the time. A driver who has to stop and work out where it goes normally fills the AdBlue side, from a bottle, and much less frequently. That gap is where the slip lives.
How AdBlue in the diesel tank occurs around Trevithal
It's hardly ever carelessness. Three things tend to line up.
To start with, the warning. Low AdBlue triggers a message from the car, and letting it run dry means limp mode — hence a hurried top-up, maybe before work off Parc An Gate, perhaps at The Ship Inn on the way home after work.
Then, your hand reaches for the cap it would have used on the old car — since a hire car, a new car or a company car puts the fillers where your last one didn't.
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. Whether it happens in Mousehole or the middle of Trevithal, it is the same few seconds.
Which filler is for AdBlue, and which for diesel?
Whether a Trevithal forecourt or a driveway out in Castallack, spend a couple of seconds over these before anything is poured in.
- The cap. The AdBlue cap is regularly blue, or marked "AdBlue". Your diesel cap usually is not. Read it instead of going by where it sits.
- Many vehicles give AdBlue the smaller filler of the two.
- The flap. Look inside the fuel flap for a label. Plenty of cars say there which fuel goes where.
- Can't see it next to your diesel inlet? In that case check beneath the bonnet or in your boot — the handbook says which.
- Collecting a hire or company car, perhaps at the car park at Penzance? Check with the person who drove the vehicle last before leaving, not when the light comes on.
Topping up AdBlue without it reaching your diesel tank
Anywhere around Cornwall the light comes on, here is a routine for the day.
- Not in a rush on the side of Mousehole Lane, not on a slope, not with the engine running: park then switch off first.
- Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds silly and it works.
- If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave the vehicle on.
- Slowly is best, through the bottle's own spout, until it's full or the bottle runs out.
- Shut the cap, and check again — confirm your diesel cap remained shut the whole time. Only then, start the vehicle.
Stop there if you find, at step two or three, that you have already poured into the diesel side. Step five is out.
Trevithal: already put AdBlue in the diesel tank?
Short list, then. Top of that: your engine stays unstarted. Leave the ignition off as well, since on many diesels switching it on alone starts your pump. Topping up with diesel won't thin it: instead, AdBlue drops to the bottom of your tank, just where fuel is taken from.
Ask the attendants to help roll the vehicle away from the petrol pump if you're at a forecourt — the Texaco, the Tesco or somewhere else. If you are on your own driveway in Trevithal, leave the car where it stands.
Already started? Pull over when it's safe, then switch off. The next junction is the place to leave if you're on the M5, over 50 miles from Trevithal. Roughly how far did it go? Hopping across Trevithal is smaller work than a run of under 50 miles to Truro, and so tell us.
Our arrival in Trevithal, and what takes place next
Wherever the vehicle came to rest, whether by Mousehole School, beside Paul Labyrinth or on your own drive, the van travels to it. We ask what went in, about how much, and whether it's run, because the answers decide this work and our price. On the call itself, you hear the quote — before anything else.
After that: a drain, then a thorough flush of the whole system. Not like petrol, AdBlue forms crystals and eats at some fuel-system metals, and none of that clears out by itself. That is why it counts more. Testing comes at the end: before that, fresh diesel is added, and your filter is flushed or changed as needed. We don't go until it has been started and is running smoothly.
Unrun vehicles usually need a half-hour visit from the moment we arrive. The kit is safe on a busy forecourt, and quiet enough for a driveway late at night. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. While we travel, take a look at your policy; many carry cover for misfuelling.
About Trevithal itself
Trevithal is a coastal locality in Cornwall, situated approximately 25 miles from Truro and 256 miles from London, with a population of around 555 people. Trevithal sits at an elevation of 80 metres, overlooking the surrounding coastline. Trevithal is characterised by its predominantly detached housing stock, reflecting its residential nature. Trevithal is close to nearby places such as Mousehole and Paul, and is part of the wider Cornwall landscape.
AdBlue drains about Trevithal, and Cornwall beyond
Throughout TR postcodes, our teams that cover Trevithal — a coastal area — work the nearby locations too, Sheffield and Paul among them. Give a postcode beginning TR19 6, and our van arrives fastest.
The vehicle does not need to shift. A drive, a lay-by on the way to Kemyel Crease, a side street near Wesleyan Chapel: our technicians drain it where it sits. Assuming won't help behind Paul Church Hall, close to a border, or anywhere hard to describe; phone and check.
Trevithal drivers: the short version
Read the cap before you pour. Even so AdBlue in the diesel tank? Petrol in Diesel will drain it wherever it stands, wherever across Cornwall: keep the car off and ring 0333 366 0103.