--- title: AdBlue in a Diesel Tank St Decumans — Don't Start It canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/st-decumans-somerset/ location: St Decumans county: Somerset latitude: 51.175180 longitude: -3.336420 service: AdBlue in a Diesel Tank updated: 2026-10-20 --- # Don't Start It: AdBlue in a Diesel Tank in St Decumans If AdBlue has got into the diesel tank, leave your engine off and leave the ignition off. Water with urea dissolved in it: that is AdBlue. Being water-based, it won't burn and never combines with diesel; damage just starts when your pump starts pulling it. Caught before the engine has been run, AdBlue in a diesel tank is generally a drain and a thorough flush, done where your car is in St Decumans. Nothing comes before ringing 0333 366 0103. ## AdBlue in your diesel tank around St Decumans: the first few minutes Do: - Keys out — that way no one can switch anything on. - Hazards on, if moving traffic is anywhere near. - The empty bottle or the till receipt shows us the fluid and the quantity, so don't bin it away. - Give us a postcode starting TA23 0, or whatever street lies nearest, and the van reaches you directly — so ring from wherever you stand. Never: - Not even briefly, and not to roll the car: the engine stays off. - Plenty of diesels power their pump the moment the ignition goes on, so keep it off. - AdBlue does not mix in diesel — it separates out — so adding extra fuel won't thin it. - Do not drive the car anywhere, not even a short way along Brendon Road. - Emptying the tank yourself beside the road is not one to try. The attendants working at any St Decumans forecourt — the Esso included — will usually help pushing it clear if you ask. At home, the vehicle remains just as it was left. ## AdBlue in a diesel tank, and what it does there Not the engine but your exhaust is where AdBlue belongs. Its own reservoir keeps it, and from there it's fed into your exhaust, and there it cleans the gas. Nothing inside an injection pump is made for this liquid — and none of it was intended to travel through one. Inside a diesel tank it acts really differently from fuel. It does not mix in. The pickup sucks fuel from the deepest part of that tank, and that's just where AdBlue settles: as it is heavier than diesel, it sinks. The first thing the fuel system pulls through, after it runs, is the AdBlue. So a motor that had AdBlue poured in on a drive in Doniford last night, and has not been started since, is still the straightforward 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. What is left once the water goes is urea, which turns into crystals: they lodge in narrow channels and block filters. On top of that, it attacks certain metals in a fuel system, and keeps going until it is flushed out. If the AdBlue is in the pipework, leaving it overnight around St Decumans leaves it worse. In your tank only, waiting does nothing. Water protects nothing. The injection pump and each injector depend on diesel flowing past them, and so the water content damages them in its own right. ## Why is AdBlue in a diesel often the bigger problem? An issue of thinned fuel is what you end up with from filling a diesel with petrol from the Q8. It mixes with your diesel, and while it is in your tank it causes no harm; the harm comes from running your motor on it. AdBlue in a diesel is a different matter: not thin fuel, yet no fuel at all. It does not burn, and so it can't simply be run through. It does not stay mixed, and so it can't be diluted. And crystals and corrosion don't wash out with the next tank of fuel. That is why the flush matters more with AdBlue than with petrol, and why starting the engine "to see" costs more here than almost anywhere else, whether your car is in Washford or the middle of St Decumans. The same good news applies as with petrol. Anywhere in Somerset your car has come to rest, an unstarted engine means the AdBlue still inside the reservoir: the simplest bit of a fuel system to clear. ## How does AdBlue end up in a diesel tank around St Decumans? It's not on purpose. Plenty of cars have the AdBlue cap beside the diesel one, now and then behind a single flap, and muddling them up is simple after dark. Usually it's never the filling station: a driver picks up a container driving home and tips it in outside the house. Usually, it occurs in one of a few familiar ways. The top-up is rushed outside Knights Templar Community Church School & Nursery, after your dash lit up with a warning while the children were taken in. After work, a bottle goes in on a driveway close to Washford Hill. Or your car is topped up in the car park at Royal British Legion, in poor light, by someone who has never opened that flap before. The least known vehicles see it most — hire cars, new ones, company ones, and the other motor in a home with both fuels. Leave it switched off: that's the first response to an identical mistake, anywhere in St Decumans or the remainder of Somerset you happen to be. ## Already started the engine with AdBlue in the diesel tank in St Decumans? Then the AdBlue has left your tank. Your filter and lines have had it pulled through, and any running time carries it on to the high-pressure pump and each injector. Lumpy running, smoke, dropping power, dashboard lights or cutting out: each might appear, perhaps midway across St Decumans or coming back from Henry Davey Playing Field. No starting it again to check: stop once it is safe, then turn everything off. Each start pulls more of it through. Leave the M5, under 25 miles from St Decumans, by the first junction and park somewhere safe, not driving on. Distance counts: each mile carries the AdBlue further in, and so heading towards Cardiff, under 25 miles away, makes a far larger job than crossing St Decumans to the car park by St Decuman's Church. About how far it had come is worth telling us. There is more to rinse out once the engine has been run, and our engineers do all of it where the vehicle has stopped. Lasting damage is very rare when it is noticed soon. ## What does an AdBlue drain on a diesel involve in St Decumans? The car remains put, whether that's a road near The Radio Museum, a drive, a lay-by or a filling station in St Decumans, and the van travels to it. Before anything else our engineers ask what was put in, roughly how much, and if the engine has been run, since those answers decide the work. Right there, the tank is then emptied, and all of the contaminated diesel and the urea leave as one. The system is flushed thoroughly, which counts more with AdBlue than with petrol, since what it leaves behind doesn't rinse out on its own. The fuel filter is flushed, or replaced where it needs to be; fresh diesel goes in; and the vehicle is tested. If the motor hasn't run, the majority of jobs take about half an hour once our technicians arrive. The pumps are explosion-proof, fine on a working forecourt and quiet enough to use outside a house after dark. The final step is to bleed your system on clean diesel. Whether it's a parking bay by the nearest station or a drive in St Decumans, that is where we start it and you drive off. Before we leave, our engineers confirm it's running properly with fresh diesel in. Our technicians do it all wherever the vehicle has stopped, and it never has to go to a garage. Insurers want a VAT invoice and an engineer report, and both come at the end. ## About St Decumans, for a moment St Decumans is a suburban area in Somerset, situated near the coast and approximately 55 metres above sea level. St Decumans is located near the towns of Watchet and Williton, and is close to the village of Five Bells. St Decumans has a population of around 1198 people and predominantly consists of semi-detached housing. ## St Decumans and Somerset: AdBlue drains across the area The teams that answer AdBlue calls around St Decumans also cover the places round it, Five Bells, Watchet and Williton among them, and most of Somerset beyond, across the TA postcode area. If you're near a boundary, or somewhere hard to explain, ring and ask instead of assuming. No moving is needed. In St Decumans, a residential suburb, a van that comes to you fits: your car is drained on the spot, whether in a driveway, a side street, a parking area or a filling station. ## What AdBlue in a diesel tank costs to put right in St Decumans Because each jobs vary, a single figure wouldn't be fair. The cost changes first with how long, if at all, the engine has been running, and next with the amount of AdBlue that got in. After that it turns on where the vehicle is and whether a technician can reach it safely, which is easier on an open drive than in a tight spot behind Watchet Boat Museum. Which fluid got in, what quantity, and whether the engine ran: each St Decumans enquiry opens by asking exactly that, before any quote, not after. Once they are known, a range becomes one firm figure. Before anyone heads out, you hear the quote on the phone. And you pay on the day, by card or over the phone, with nothing in advance. Look at your insurance whilst we are on the way: many carry misfuelling cover. ## Alongside your car around St Decumans, right now? Not touching your car is, then, the best move open to you. Keys out, engine off, ignition off. Phone 0333 366 0103: AdBlue, the amount, plus whether the engine ran are everything our engineers ask. Petrol in Diesel handles the rest throughout Somerset, St Decumans too.