How It Occurs and How to Avoid It: AdBlue in a Diesel Tank in Portherras
Pause reading a minute if the diesel tank already holds AdBlue in it: ignition off, motor off, and phone 0333 366 0103. Caught before your engine runs, it is usually a drain and a thorough flush, done where the car is in Portherras. The rest of this page covers why it occurs and how to ensure it does not — handy if you are reading ahead of time.
Why does AdBlue in a diesel car need its own filler?
Plenty of modern diesels on the roads around Portherras and Lower Boscaswell carry two liquids, not one. Diesel goes to the engine. Your exhaust, not your motor, is where AdBlue goes: dosed into the gas to fresh them, from its own tank.
Different tanks, different fillers. Under one flap, next to each other: that is the arrangement on many vehicles. On others, AdBlue's filler sits beneath the bonnet or in your boot instead. The diesel side is fuelled at the petrol pump all the time. Seldom topped up, AdBlue normally comes out of a bottle, poured by someone who must stop and think what filler to use. The slip lives in that gap.
AdBlue in the diesel tank in Portherras: how it occurs
It is seldom carelessness. Three things tend to line up.
To start with, the warning. Low AdBlue brings a message from your car, and running dry leads to limp mode — hence a hurried top-up, maybe before work off Saint Ives Road, or outside The North Inn on the way home after work.
Then the vehicle is new. A hire car, a new motor or a company car puts the fillers where your last one didn't, and your hand reaches for the cap it would have used on the old one.
Third, the spout fits: a diesel filler or AdBlue one, it goes in just as readily, and once the tip begins, nothing halts it. The same few seconds decide it, in the middle of Portherras or out in Higher Bojewyan.
Which filler is for AdBlue, and which for diesel?
Be it a Portherras forecourt or a drive over in Trewellard, spend a few seconds over these before anything is poured in.
- Where it sits misleads; the cap does not. AdBlue caps tend to be blue or carry the word "AdBlue" — diesel ones normally don't.
- On plenty of motors, the size tells: AdBlue has the smaller filler neck.
- Lift the filler flap and check for a label — plenty of motors show which belongs in each inlet just there.
- Can't see it beside the diesel filler? In that case check below the bonnet or inside the boot — the handbook says which.
- Picking up a hire or company car, perhaps at the car park outside Penzance? Check with whoever drove the vehicle last before you set off, not once the light goes on.
Keeping AdBlue out of the diesel tank when you top up
On the day the warning comes on — anywhere it is around Cornwall — a simple routine to use.
- Pull in somewhere level, motor off, with time to spare — never rushing on the side of B3306.
- Say "AdBlue" out loud as you unscrew the cap, after finding the AdBlue filler and read it. Silly, perhaps, yet it does the trick.
- Both under one flap? So make sure the lid on the diesel side stays closed before raising the bottle.
- Gently is best, through the bottle's own spout, until it's full or the bottle runs out.
- Close the cap, and look once more — making sure the diesel filler stayed closed the whole time. Only then, start the car.
Find at the second or third stage that the bottle went into the wrong tank? That is where you stop. Never carry on to step five.
Put AdBlue in your diesel tank around Portherras already?
What follows is a short order of things, starting with not starting the motor. On many diesels the ignition alone runs the fuel pump, and so don't switch the car on. AdBlue doesn't mix with diesel — it sinks to the bottom of your tank, where the fuel is sucked from — so do not top up with diesel to thin it.
The attendants at Trewellard Garage, another forecourt nearby or another forecourt will normally help to push your car clear if asked. Leave it where it is if you're on your own drive around Portherras.
Already run? Stop once it's sensible, then turn off. Portherras sits over 50 miles from the M5; there, use the first junction. Mileage matters — a short hop across Portherras makes a smaller job than driving under 50 miles towards Truro — so tell us roughly how far it went.
What happens when we get there in Portherras
Outside Pendeen School, near Engine House or on your own driveway: wherever the car has stopped, we come to it. Our engineers ask what got in, roughly how much, and whether it has run, because those answers decide the work and our quote. You get that quote by phone, before anybody sets off.
Draining that tank comes next, then a full flush of the fuel system. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, so it does not wash out on its own. The filter flushed or, where needed, swapped; fresh diesel in; then a check of your vehicle. Before we leave, our technicians fire it up and confirm that it is running correctly.
Unrun vehicles usually need a half-hour visit after arrival. The kit is safe on a busy forecourt, and hushed enough for a driveway late at night. Paying is on the day, not upfront, and you receive the documents your insurer asks for: an engineer's report and a VAT invoice. Plenty of insurance policies include misfuelling cover, so it's worth checking yours whilst we are on the way.
About Portherras itself
Portherras is a small suburban area situated on the coast of Cornwall, with its elevation at around 137 metres providing views out to sea. Portherras is located near several nearby villages, including Higher Bojewyan, Pendeen, and Higher Boscaswell, and is approximately 27.9 miles from the city of Truro. Portherras has a population of around 604 people, predominantly living in terraced housing.
AdBlue drains across Cornwall, Portherras included
Portherras is a residential suburb, and the vans that cover it also work the towns near it, Pendeen and Higher Boscaswell among them, across the TR postcode area. A postcode starting TR19 7 gets our van to you fastest.
Shifting your car isn't necessary. Wherever it stands — near Chimney, on a lay-by en route to Borlaze Park, at home — that is where it is emptied. If you are near a border, or somewhere hard to explain like the back of St John the Baptist, ring and ask rather than guessing.
In short, for Portherras drivers
Read the cap before you tip. AdBlue in the diesel tank regardless? Keep it off then call 0333 366 0103; Petrol in Diesel empties it where it stands, throughout Cornwall.