--- title: AdBlue in a Diesel Tank Harmondsworth: What Now canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/harmondsworth-greater-london/ location: Harmondsworth county: Greater London latitude: 51.488690 longitude: -0.478940 service: AdBlue in a Diesel Tank updated: 2026-10-26 --- # AdBlue in the Diesel Tank in Harmondsworth, and What to Do Next All of it turns on one detail: whether your motor has been run after the AdBlue went in — far more than anything else. Over in Thorney or right around Harmondsworth, an unstarted engine should remain unrun. Usually that means emptying and properly purging it right there in Harmondsworth — so keep the key and motor off then ring 0333 366 0103. If it's run, stop as soon as it is safe then switch off. The job is bigger, but the first step is the same. Compare your case to a situation from the ones below, wherever around Greater London you happen to be. ## Harmondsworth forecourt: AdBlue in a diesel at the pump You're at the petrol pump, the nozzle or the bottle still in your hand, and you have just noticed the cap you opened was the wrong one. Be it Shell, Esso or somewhere else in Harmondsworth, the case is the same. In short: there is no better place to be to spot it. No pump has drawn it in, so the AdBlue sits just in the tank. Next: resist the urge to start it just to free up the pump. Ask the attendants to help you push your car into a parking bay, keep the receipt or the bottle, then phone us from the forecourt. Stuck by the petrol pump? Explosion-proof kit keeps a busy forecourt sensible, so it can be drained where it is. ## AdBlue in your diesel tank on a Harmondsworth drive? Several days had gone by with the warning light on. Only by the recycling, the empty bottle in your hand, did you glance back at the cap you'd opened on the driveway. It takes place on drives just off Moor Lane as commonly as anywhere. What it means: if you haven't driven since, this is almost as good as the forecourt. At the bottom of your tank is where AdBlue stays, because it will not blend with diesel — and a night passing changes no difference. Keep your keys indoors tonight — otherwise someone may drive it off at breakfast — and phone us. Longford or Harmondsworth: wherever your driveway sits, that is where it gets cleared. Even at night, our pumps stay quiet enough for a driveway. ## On the road around Harmondsworth with AdBlue in a diesel A mile or two beyond topping up, your motor started misbehaving: rough running, smoke, lost power, warnings on the dash. Somewhere along Summerhouse Lane or heading towards Westminster — under 25 miles away. What it means: the system has drawn the AdBlue in. The injection pump and each injector see it as well on a bigger trip, after the fuel filter and lines have it. Each mile and each restart takes it further. What to do: pull over where it's safe to do so and switch off. Services farther on can wait: from the M4, under a mile out of Harmondsworth, use the next junction. Do not restart the vehicle to see if it has cleared; it will not have. Phone, and say how far the vehicle went. ## Hire, lease or company car with AdBlue in the wrong tank You have just driven the vehicle a week. Your own motor either has no AdBlue or keeps it somewhere different, so nothing warned you the AdBlue cap sits just beside your diesel. Wherever you are across Greater London, every motorist could be caught. What it means: the same as the situations above, depending on whether it has run, with one more stage. Plenty of hire and company contracts want the owner to approve work on the vehicle. Your move: rental firm or fleet manager to begin with, us next, because settling it beforehand saves time. Leave the car switched off as the answer arrives, even if you're waiting at Heathrow Terminal 5 Rail or near St Mary's. ## Harmondsworth: unsure if it was AdBlue in your diesel tank? At times the honest answer is "I think so". A slight ammonia whiff hangs around the filler, the bottle feels too light, and the cap you took off is a blur. The gates of Harmondsworth Primary School in a hurry, say, or someone's drive out in Poyle. Meaning? Spills outside the filler don't reach your motor at all. AdBlue inside the diesel tank does. Any AdBlue in the tank would be sucked in by starting the vehicle, and the start would not settle which it is in any case. Take it that it got in, and don't start the key. Call us and explain what you saw; we would rather check a tank that turns out free of AdBlue than drain one that has already been run. ## Each AdBlue drain around Harmondsworth shares these steps Whatever the case, a single opening applies. Three things come once we arrive — on a forecourt, a driveway, a street beside Harmondsworth Great Barn or the car park at The Five Bells: the fluid, the amount, and whether the motor has been started. The price comes on the call, before a van leaves, and the replies set the job. Emptying your tank comes next, then a careful flush — more vital after urea than after petrol, because crystals and corrosion won't go by themselves, however long it sits. Clean diesel is put in once the fuel filter is flushed or replaced, and the car is then checked. Where your motor has not been started, expect about half an hour on site, for most cases. Firing it up comes last. Before our technicians leave, it's tested to make sure it runs properly on fresh diesel. Our technicians do the whole job where your car is, and lasting damage is very rare when it has been spotted soon. Payment comes on the day, never upfront. For your insurer, you get a VAT invoice plus a report from the engineer. Plenty of insurance policies cover misfuelling, so look at yours as we head over. ## About Harmondsworth and where it is Harmondsworth is a suburban area in the London Borough of Hillingdon, situated on the River Colne at an elevation of around 28 metres. Harmondsworth lies near the villages of Longford, Sipson, and West Drayton, and is approximately 15 miles west of central London. Harmondsworth is characterised by its semi-detached housing stock and quiet residential atmosphere. Harmondsworth has a population of around 1161 people, according to recent estimates. ## AdBlue drains around Harmondsworth and across Greater London Over UB postcodes, the vans serving Harmondsworth — a residential suburb — reach nearby towns too, Sipson and West Drayton included. Fastest of all: a UB7 0 postcode for your location. Parked heading to Harmondsworth Recreation Ground, or bang in the centre of Harmondsworth, your car remains put — there is no need to move it anywhere. Where it stands, that's where it gets cleared. Ring and check instead of guessing if you are close to Harmondsworth Baptist Church, near a border, or somewhere tricky to pin down. ## Your scenario, summed up Not run yet: keep the car off then ring. Already run: stop, switch off then call. Either way, Petrol in Diesel takes it from there in Harmondsworth and anywhere around Greater London on 0333 366 0103.