Cambridge: AdBlue in the Diesel Tank? Leave It Off
If AdBlue has got into the diesel tank, keep the engine off and keep your ignition off. Urea mixed in water is all AdBlue is. The trouble begins once it's sucked through the lines — it will not burn, and it won't combine with diesel. In Cambridge, AdBlue in a diesel tank caught before your engine runs normally comes down to a drain and a thorough flush, just where the car is. Before you do anything else, ring 0333 366 0103.
What to do straight away, Cambridge: AdBlue in your diesel tank
Things to do:
- Keys out — that way nobody can power anything on.
- Hazards on, if moving traffic is anywhere close.
- The empty bottle or the till receipt shows us the fluid and the amount, so don't throw it out.
- Tell us a postcode starting CB1 0, or whatever street is closest, and our van reaches you straight — so call from wherever you stand.
Things not to do:
- Not even for a second, and not to shift your car: the engine remains off.
- The ignition stays off: on many diesels, switching it on is enough to run the fuel pump.
- Do not top up with diesel to thin it. AdBlue does not dilute in diesel; it separates out.
- Keep it where it is rather than driving it anywhere, even a short distance up Guildhall Street.
- Emptying that tank on your own beside the road is not worth trying.
Ask the people behind the counter to help you move the vehicle away from the island if you are on a forecourt in Cambridge, whether it's the Shell or somewhere else. If you are on your own drive, leave the vehicle exactly where it is.
AdBlue in a diesel tank, and what it does there
AdBlue is made for your exhaust, not the engine. From a separate tank it is fed straight to the exhaust, cleaning what the engine emits. Nothing inside a fuel pump is made for this fluid — and none of it was meant to go through one.
Inside a diesel tank it behaves very differently from fuel. It does not mix in. The intake sucks fuel from the deepest part of the tank, and that is just where AdBlue ends up: as it is heavier than diesel, it sinks. The first thing your fuel system pulls through, after it runs, is the AdBlue. So a car that had AdBlue poured in on a drive in Romsey Town last night, and has not been started since, is still the easy case: the AdBlue is lying at the bottom of that tank, and nothing has pulled it in.
From there it causes two kinds of damage. It attacks some metals found in fuel systems, working on whatever it touches until it is cleared completely. And once the water goes, the urea forms crystals that clog filters and settle in tiny channels. Pipes holding AdBlue spell harm by morning for a vehicle sitting around Cambridge. Only inside the tank, it stays the same. Diesel lubricates the high-pressure pump and every injector as it flows; water gives no lubrication, and that is a separate kind of damage.
Why is AdBlue in a diesel often the bigger fault?
Top up a diesel with petrol in error over at the BP, and the issue is thinned fuel. Mixed through your diesel and sitting unused, it's harmless for now; running your engine does the harm.
AdBlue in a diesel is a fault of the wrong substance altogether. It can't just be run through, because it doesn't burn. It does not stay mixed, so it can't be thinned. And crystals and corrosion do not wash out with the next tank of fuel. That is why the flush matters more with AdBlue than with petrol, and why starting your engine "to see" costs more here than nearly anywhere else, whether the car is in Arbury or the middle of Cambridge.
With AdBlue, the good news is no separate from petrol. If the motor has not run, the AdBlue is still inside the tank, and your tank is the easiest part of a fuel system to clear, wherever across Cambridgeshire your car is sitting.
How AdBlue ends up in a diesel tank around Cambridge
After dark, two caps together — the AdBlue one and the diesel cap, occasionally behind one flap — can look the same. No one means it; plenty of designs allow it. Mostly it is never the filling station: someone picks up a container driving home and tips it in outside the house.
A couple of familiar ways account for most cases. A warning light comes on during the school run, and the top-up occurs in a hurry outside Park Street CofE Primary School. A bottle is poured in at the end of the day on a drive just off Petty Cury. Another version: darkness, the car park outside The Pint Shop, and someone using that flap for the first time.
It happens most in the cars motorists know least: a hire car, a new car, a company car, or the second car of a household with one diesel and one petrol. Anywhere in Cambridgeshire, Cambridge included, the mistake doesn't change, and neither does the first response: keep it off.
Cambridge: started your engine with AdBlue in the diesel tank?
In that case, the AdBlue is no longer inside the tank. With any running, it goes on to the injection pump and each injector, after passing via your filter and lines.
You may see the engine running roughly, smoking, losing power, showing warning lights or cutting out, maybe on the way back from Bursar's Garden or halfway across Cambridge. Stop as soon as it is safe, switch off, and don't restart it to check. More of it is pulled through with each start.
On the M11, under 3 miles from Cambridge, the next junction is where to leave, and somewhere safe is where to stop — not driving on.
How far it went matters. A couple of hundred yards across Cambridge to the car park by Talos is a very different job from a run towards Ely, under 15 miles away, with the AdBlue reaching further into the fuel system with every mile. Roughly how far it had come is worth telling us.
We do all of the rinsing where the vehicle has ended up, and once your engine has been started there is more of it. Noticed early, it very seldom leaves lasting damage.
Emptying AdBlue in a diesel around Cambridge: what it takes
We come to the car, wherever it has stopped around Cambridge: a side street close to Snowy, a drive, a lay-by or a forecourt. The work rests on three answers, which our technicians ask for before all else — which fluid went in, the amount, and whether the motor has run.
The polluted diesel and the urea leave together after the tank is emptied, right there. With AdBlue, more so than with petrol, flushing counts: the fuel system is cleaned all the way through since residue won't flush out unaided. Next, the filter: cleaned, or changed when it must be. Then fresh diesel, then a check of your car. Not run? Then expect about half an hour on site for most jobs. The pumps are explosion-proof, safe on a busy forecourt and quiet enough to use outside a house at night.
Lastly, the fuel system is bled with new diesel. Whether it's a parking space outside the nearest station or a drive around Cambridge, that is where we start it and you drive off. Before we leave, our engineers check it's running correctly with clean diesel in. As the job is done in its entirety where the vehicle is, a garage never comes into it. You receive a VAT invoice and an engineer report after that, which is what insurers want.
About Cambridge and where it is
Cambridge is a historic city situated in the east of England, on the banks of the River Cam. It serves as the main town of Cambridgeshire, with a rich past that spans thousands of years. Cambridge has developed from a significant centre of trade and commerce in ancient times to a thriving urban area. The city's scenic riverside setting adds to its charm and character.
AdBlue drains in Cambridge and across Cambridgeshire
Newnham Croft, Newnham and Newtown are among the places around Cambridge that the same vans serve, together with much of Cambridgeshire further out, over the CB postcode area. Assuming won't help close to a county line or anywhere hard to describe; phone and ask.
A mobile service fits Cambridge, a city: there's no need to take your car to us, since our engineers drain it there, in a driveway, a side street, a parking area or a forecourt.
What AdBlue in a diesel tank costs to put right around Cambridge
Every job differs, so no single price would be fair. What changes the cost is, first, whether your engine has been running and for how long; then how much AdBlue went in; and finally where the car is and whether a technician can get to it safely, which is easier on an open drive than in a tight space behind Cambridge University Catholic Chaplaincy, Chapel of St John Fisher.
That is why each call from Cambridge starts with the same three questions, asked before giving a figure, not after: what was put in, how much, and if it has run. With those replies, the range shrinks to a single fixed figure.
Quoted by phone before the van sets out, the job is paid for that day — card or phone, nothing in advance. While the van is travelling, check your policy: many cover misfuelling.
In Cambridge and still alongside your car?
Then the most handy thing you can do is nothing to your car. Keys out, motor off, ignition off. Ring 0333 366 0103 and tell us it is AdBlue, about how much, and whether it's run. Petrol in Diesel takes it from there, around Cambridge or anywhere around Cambridgeshire.