Preventing AdBlue in a Diesel Tank in Gerrans: Why It Occurs
Leave your motor and ignition off then phone 0333 366 0103 first — the rest can wait if AdBlue is already in the diesel tank. Around Gerrans, catching it before your engine runs usually leaves a drain and a full flush on the spot. The remainder of this page explains why it happens and how to ensure it doesn't — useful if you're reading ahead of time.
AdBlue in a diesel motor: two tanks, two fillers
Many newer diesels around Percuil, like those in Gerrans, run on two liquids; the engine gets only the diesel. The exhaust, not the motor, is where AdBlue ends up: dosed into the gas to fresh it, from a separate tank.
Separate tanks, different fillers. Some vehicles put the AdBlue filler in your boot or under the bonnet; plenty more place the two together behind one flap. Filling the diesel side at the pump happens constantly. Far less regularly, the AdBlue side is filled — normally from a bottle, by someone working out where it goes. Mistakes happen in the gap between them.
How AdBlue in the diesel tank occurs in Gerrans
Seldom is it carelessness: normally three things coincide.
The warning comes first. As AdBlue runs low your car tells you, and if it runs out completely, the vehicle goes into limp mode. So the top-up is done in a hurry: on a drive off Gerrans Square before work, or in the car park outside The Standard Inn on the way home.
Then the car is strange. A hire car, a new motor or a company car puts the fillers where your last one did not, and the hand hits for the cap it would have used on the old one.
A spout-topped bottle finds no resistance at a diesel filler no more than at an AdBlue one. So the pour, after begun, carries on. It takes a few seconds, be it out in Portscatho or right in the heart of Gerrans.
Telling the AdBlue filler from your diesel filler
Whether a Gerrans forecourt or a driveway out in St Just in Roseland, take a few seconds on these before any is poured in.
- Read the cap rather than going by where it sits: AdBlue ones are frequently blue or marked "AdBlue", and diesel ones usually aren't.
- The size. On many motors the AdBlue filler neck is the smaller of the two.
- Look inside your fuel flap: plenty of cars have a label there showing which fuel goes where.
- The handbook. If your filler is not 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, perhaps at the car park at Falmouth Docks? Ask the person who drove the vehicle last before you set off, rather than when the light goes on.
AdBlue top-ups that never reach the diesel tank
When the light comes on, wherever across Cornwall, follow this routine.
- Switch off after you park — flat ground, motor off, and not rushed beside Treloan Lane at the roadside.
- Find the AdBlue filler, read the cap, and speak the word "AdBlue" aloud while unscrewing it. It seems silly. It works.
- Both under one flap? So confirm the cap on your diesel side stays closed before raising the bottle.
- Stop when the tank is topped up or the bottle is empty; until then, tip gently through its built-in spout.
- Close the cap and check once more. Make sure the diesel cap was never opened. Only then start your car.
Discover at the second or third stage that AdBlue went in the diesel tank? That is where you stop. Don't go on to stage five.
Already put AdBlue in your diesel tank around Gerrans?
Then the order of things is short. Do not start the motor. The fuel pump starts on plenty of diesels as soon as the ignition goes on — and so keep it off. Thinning it with extra diesel won't work, because AdBlue settles to the bottom instead of blending — and that is where the fuel is drawn from.
At a forecourt — Esso, another forecourt nearby or any other — the attendants will normally help push the vehicle clear, if you ask. On your own drive in Gerrans? Then the vehicle stays put.
Stop as soon as it is safe then switch off, if the motor has already run. Gerrans sits over 50 miles from the M5; on it, use the next junction. Mileage matters — a short hop across Gerrans makes a smaller job than heading under 10 miles towards Truro — so say roughly how far it went.
Our arrival around Gerrans, and what happens next
By Gerrans School, close to St Gerrans or on your own drive: wherever the vehicle has stopped, our engineers come to it. Both the work and the quote depend on three replies — which liquid, which quantity, and if it's run — so our engineers ask. The price comes on the call, ahead of any van leaving.
Emptying your tank comes next, followed by a thorough flush of your system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own — which is why that counts more here than with petrol. After the fuel filter is cleaned — or replaced, if needed — fresh diesel is added, and then your vehicle gets tested. The engine is fired up next and checked to be sure it runs properly, all before we leave.
If your engine hasn't run, the majority of jobs take about half an hour once we are there, using pumps that are fine on a working forecourt and quiet enough to use outside a house after dark. Nothing in advance; you settle up on the day. At the end, a VAT invoice and a report from the engineer are handed to you for the insurer. It is worth looking at your policy while we travel to you: misfuelling cover comes with many policies.
About Gerrans
Gerrans is a coastal village in Cornwall, situated near the Roseland Peninsula and overlooking the sea. Gerrans has a population of around 834 people and is characterised by its predominantly detached housing stock. Gerrans is close to the nearby villages of Portscatho and Rosevine, and is about 6.6 miles from the city of Truro. Gerrans sits at an elevation of 57 metres above sea level, in a scenic area of the South West region.
Gerrans and Cornwall: AdBlue drains across the area
As a coastal village, Gerrans shares its vans nearby areas — Rosevine, Trethewell — all the way across TR postcodes and the surrounding area around them. A postcode starting TR2 5 gets the van to you fastest.
The car stays put. A driveway, a lay-by on the way to Drawler Plantation, a side street close to Monument to General Slim: our technicians drain the car where it sits. Awkward to explain, like the back of The Roseland Centre? By a border? Asking is better than assuming, and so phone.
The short version for Gerrans motorists
Tip no AdBlue till you have read the cap. Even so AdBlue in the diesel tank? Petrol in Diesel can empty it wherever it stands, wherever around Cornwall: keep the car off and call 0333 366 0103.