--- title: AdBlue in a Diesel Tank Parliament Hill: Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/parliament-hill-greater-london/ location: Parliament Hill county: Greater London latitude: 51.567140 longitude: -0.153840 service: AdBlue in a Diesel Tank updated: 2026-10-27 --- # Parliament Hill: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? Pause reading for a moment if the diesel tank already has AdBlue in it: ignition off, motor off, and phone 0333 366 0103. Around Parliament Hill, catching it before your motor turns usually means a drain and a thorough flush where it stands. Not happened yet? Further down, the rest of the page covers the why it occurs and the ways to prevent it altogether. ## Two fillers, two tanks: AdBlue in a diesel motor Diesel goes to your motor — but plenty of modern diesels seen around Parliament Hill and Gospel Oak carry a second fluid as well. Stored in a tank of its own, AdBlue is fed into the exhaust stream to clean it. Different tanks, separate fillers. On a lot of motors the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. Diesel gets filled on each filling station call-out, week in, week out. Far less often, the AdBlue side gets topped up — mostly from a bottle, by someone working out where it goes. The mistake lives in that gap. ## AdBlue in the diesel tank around Parliament Hill: how it happens It is seldom carelessness. Three things tend to line up. On a driveway off Holly Lodge Gardens before work, or in the car park at The Flask on the way home: that is where the rushed top-up takes place. What is the reason for the rush? As AdBlue runs low your car warns you, and once it's gone, limp mode follows. Then, the hand reaches for the cap it would have used on the old car — since a hire car, a new car or a company car puts the fillers somewhere your last one did not. Lastly, the spout goes in: a diesel filler or AdBlue one, it slides in as readily, and once the tip starts, nothing halts it. Dartmouth Park or the heart of Parliament Hill: it is the same few seconds in both. ## The AdBlue filler and the diesel filler: telling them apart Be it a Parliament Hill forecourt or a drive out in Upper Holloway, spend a couple of seconds over these before any goes in. - The cap. The AdBlue cap is commonly blue, or marked "AdBlue". Your diesel cap normally isn't. Read it instead of going by position. - The size. On plenty of motors the AdBlue filler neck is the smaller of the two. - Look inside the fuel flap: plenty of vehicles have a label there showing which fuel goes where. - Cannot see it next to your diesel filler? In that case look beneath the bonnet or in your boot — the handbook will say which. - The previous driver knows. Check as you pick up a hire car or company car — from Gospel Oak's car park, say — not when the warning appears. ## Topping up AdBlue without it reaching the diesel tank On the day the warning appears — anywhere you are in Greater London — a simple routine to follow. - Not in a rush on the side of Highgate West Hill, not on a slope, not with your motor running: park and switch off first. - Say "AdBlue" out loud as you unscrew the cap, after you find the AdBlue filler and reading it. Daft, yes, but it works. - If both sit under one flap, check the diesel cap is still closed before you lift the bottle — and leave the vehicle on. - Gently is best, through the bottle's own spout, until it is full or the bottle runs out. - Close the cap, then check again — confirm the diesel cap stayed closed the whole time. Only then, start the vehicle. Stop there if you find, at step two or three, that you've already poured into your diesel side. Never carry on to stage five. ## AdBlue in your diesel tank already, in Parliament Hill? Then the order of things is short. Do not start your motor. Keep the ignition off as well, because on plenty of diesels it by itself starts your fuel pump. Diluting it with more diesel won't work, because AdBlue settles to the base instead of blending — and that's where the fuel is pulled from. The staff at Gulf, Esso or any forecourt will usually lend a hand pushing the car away when asked. Your own driveway around Parliament Hill is where it stays. When the engine has run by now, stop somewhere safe then turn it off. Parliament Hill lies under 5 miles from the M1; on it, take the next exit. Tell us roughly how far it went: a run towards London, under 5 miles away, is a bigger job than a short hop across Parliament Hill. ## Parliament Hill: what takes place when we arrive Our van reaches the vehicle anywhere it stopped — your own drive, beside John Betjeman, or outside St Michael's CofE Voluntary Aided Primary School. Both the work and the price depend on three answers — which liquid, what quantity, and whether it's run — so our engineers ask. On the phone call itself, you are told our quote — before anything else. Then the tank is cleared and the system flushed thoroughly. More than with petrol, it matters with AdBlue: crystals build up, some metals are attacked, and none of it clears away unaided, no matter how long it is left. After the filter has been cleaned — or renewed, where required — fresh diesel goes in, and finally the car is tested. Before leaving, our engineers start the engine and confirm that it is running smoothly. If the motor has not run, most jobs take about half an hour once we are there, using pumps that are fine on a busy forecourt and quiet enough to use outside a house after dark. No money upfront; you settle up that day. At the end, a VAT invoice and the report from the engineer are handed to you for your insurer. Misfuelling cover is included in plenty of insurance policies — so use the wait to look at yours. ## About Parliament Hill, for a moment Parliament Hill is a suburban area in north London, situated near the River Fleet and overlooking the city. Parliament Hill sits at an elevation of 106 metres, providing views across the surrounding area. Parliament Hill is characterized by its predominantly flat-type housing and is located near other neighbourhoods such as Dartmouth Park and Highgate. Parliament Hill is a relatively small community with a population of around 3520 residents. ## AdBlue drains about Parliament Hill, and Greater London beyond Highgate and Archway are among the places around Parliament Hill, a residential suburb, that the same teams cover, throughout N postcodes. Quickest of all: quote a N6 6 postcode to our van. The vehicle does not need to shift. Wherever it stands — near St Michael's Church, in a lay-by en route to Pond Square, at home — that's where it is drained. If you're near a boundary, or somewhere hard to explain like the back of J. B. Priestley, ring and ask rather than guessing. ## For Parliament Hill motorists, the short version First, the cap; after that, the pour. Even so AdBlue in the diesel tank? Petrol in Diesel will empty it where it is, wherever in Greater London: keep the car off then call 0333 366 0103.