Avoiding AdBlue in a Diesel Tank in Lea Valley: Why It Happens
Keep the engine and ignition off then ring 0333 366 0103 first — the rest can wait if AdBlue is already in the diesel tank. A drain plus a thorough flush, carried out right where the vehicle stands around Lea Valley, is normally all it needs if found before your motor runs. The remainder of this page covers why it happens and how to ensure it does not — useful if you are reading before it has happened.
AdBlue in a diesel motor: two tanks, two fillers
Many modern diesels around Mackerye End, as well as Lea Valley, run on two liquids; your engine takes just the diesel. Your exhaust, not your motor, is where AdBlue goes: dosed into the gas to fresh them, from a separate tank.
Different tanks, separate fillers. Some vehicles put the AdBlue filler in the boot or under the bonnet; plenty more place the two together under one flap. Diesel gets filled at each forecourt call-out, week in, week out. Someone who has to stop and work out where it goes normally fills the AdBlue side, from a bottle, and far less commonly. The mistake lives in that gap.
Lea Valley: how AdBlue in the diesel tank takes place
Rarely is it carelessness: usually three things coincide.
The warning comes first. As AdBlue runs low your car tells you, and if it runs out altogether, the car goes into limp mode. So the top-up is done in a hurry: on a drive off Lower Luton Road before work, or in the car park at Marquis of Granby on the way home.
Next, the hand reaches for the cap it would have used on the old motor — since a hire car, a new vehicle or a company car places the fillers somewhere your last one didn't.
No part stops the tip once it has started, since a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. Leasey Bridge or the heart of Lea Valley: it is the same few seconds either way.
Which filler is for AdBlue, and which for diesel?
Check these first, at a forecourt in Lea Valley or a drive over in Amwell. A few seconds, no more.
- Blue and marking: an AdBlue cap is commonly blue, or says "AdBlue", where a diesel cap normally doesn't. Go by the cap, not where it sits.
- Many motors fit AdBlue the smaller filler of the two.
- The flap. Look inside the fuel flap for a label. Many vehicles say there which fuel goes where.
- The handbook shows which it is if your filler isn't next to your diesel cap: the boot, or under the bonnet.
- Ask 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 outside Harpenden.
Topping up AdBlue without it reaching the diesel tank
Wherever across Hertfordshire the light comes on, this is a routine for the day.
- Not in a rush on the side of Cherry Tree Lane, not on a slope, not with the motor running: park then switch off first.
- Find the AdBlue filler, read the cap, and say the name "AdBlue" out loud as you unscrew 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.
- Pour slowly, using the bottle's own spout. Stop when it is full or when the bottle is empty.
- Close the cap, and check once more — making sure the diesel cap stayed shut throughout. After that, start the car.
Stop there if you find, at stage two or three, that you have already poured into the diesel side. Never go on to stage five.
Put AdBlue in your diesel tank around Lea Valley already?
Short order, then. Top of that: your motor stays off. Keep your ignition off as well, because on plenty of diesels it alone starts the fuel pump. AdBlue does not mix with diesel — it sinks to the bottom of the tank, where your fuel is pulled from — so do not top up with diesel to dilute it.
Ask the attendants to help roll the vehicle away from the pump if you are on a forecourt — the Esso, the BP or somewhere else. On your own drive around Lea Valley? Then your car stays where it is.
If the motor has already run, stop as soon as it is safe and switch off. On the A1(M), under 5 miles from Lea Valley, that means the next exit. A short hop across Lea Valley is a smaller job than a run towards St Albans, under 5 miles away, and so tell us roughly how far it went.
Our arrival around Lea Valley, and what takes place next
By High Beeches Primary School, near Bury Farm Cottages or on your own driveway: wherever the vehicle has stopped, our technicians come to it. Both the work and our price rest on three answers — what fluid, what amount, and if it's run — so our technicians ask. You hear that quote by phone, before anyone sets off.
After that: draining, then a full flush of the whole system. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own — which is why the flush counts more here than with petrol. The filter is flushed, or replaced where it needs to be; fresh diesel goes in; and the vehicle is tested. We do not go until it has been started and is running correctly.
If the motor hasn't run, the majority of jobs take about half an hour once we're there, using pumps that are safe on a busy forecourt and quiet enough to use outside a house at night. Nothing upfront; you settle up that day. At the end, a VAT invoice and a report from the engineer go to you for the insurer. It's worth checking your policy as the van travels to you: misfuelling cover is included with many policies.
About Lea Valley and where it is
Lea Valley is a small village in Hertfordshire, situated on the banks of the River Lea at an elevation of around 88 metres. Lea Valley lies approximately 23 miles north of London and 4.7 miles southeast of St Albans, with nearby places including Leasey Bridge and Marshalls Heath. Lea Valley has a population of around 672 people, predominantly living in semi-detached houses.
AdBlue drains in Lea Valley and across Hertfordshire
Being a village, Lea Valley has the same vans as nearby areas — The Folly, Marshalls Heath — all the way through AL postcodes and the surrounding area around them. A postcode starting AL4 8 gets the van to you fastest.
No need to move your car. The drain happens on the spot, be it a drive, a street near Wheathampstead United Church, or a lay-by on the way to Melissa Field. Awkward to pin down, like the back of Crabtree Church? By a border? Checking is better than assuming, so ring.
The short version for Lea Valley motorists
Always, the cap; after that, the pour. Petrol in Diesel drains it on the spot, anywhere around Hertfordshire, if AdBlue has gone in the diesel tank anyway — so leave it off then call 0333 366 0103.