--- title: Explained: AdBlue in a Diesel Tank Highgate canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/highgate-west-midlands/ location: Highgate county: West Midlands latitude: 52.465510 longitude: -1.891550 service: AdBlue in a Diesel Tank updated: 2026-10-24 --- # Highgate: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? Pause reading for a moment when your diesel tank already has AdBlue in it: ignition off, engine off, and ring 0333 366 0103. Normally, when the motor has not turned, it is emptied and fully flushed where your car sits in Highgate. The remainder of this page explains why it happens and how to ensure it does not — useful if you're reading ahead of time. ## AdBlue in a diesel car: two tanks, two fillers Many newer diesels in Bordesley, as well as Highgate, run on two fluids; your engine takes only the diesel. Its own tank keeps it, and from there it goes to your exhaust, where a spray treats the gas. Every tank has a filler of its own. Some vehicles put the AdBlue filler in your boot or under the bonnet; a lot of others have both side by side under one flap. Diesel goes in at each filling station call-out, week in, week out. Someone who has to stop and think where it goes normally fills the AdBlue side, from a bottle, and far less frequently. That gap is where the slip lives. ## How AdBlue in the diesel tank happens in Highgate It's hardly ever carelessness. Three things tend to line up. On a drive off Highgate Street before work, or in the car park at The Town Crier heading home: that's where the hurried top-up happens. What is the reason for the rush? As AdBlue runs low your car warns you, and once it is gone, limp mode kicks in. Then your car is new. A hire car, a new car or a company car puts the fillers where your last one did not, and your hand hits for the cap it would have used on the old one. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, and so nothing stops the pour once it has started. Whether it happens in Deritend or the middle of Highgate, it's the same few seconds. ## Telling the AdBlue filler from the diesel filler Check these before pouring, at a forecourt around Highgate or a drive out in Lee Bank. Seconds, no more. - The cap. The AdBlue cap is regularly blue, or marked "AdBlue". The diesel cap normally isn't. Read it rather than going by where it sits. - On many vehicles, the size gives it away: AdBlue gets the smaller filler neck. - Open the filler flap and check for a label — many cars mark what goes in which filler right there. - In the boot or under the bonnet: that's where your filler sits if it is not by your diesel cap, and the handbook says which. - Collecting a hire or company car, perhaps at the car park outside Bordesley? Ask the person who drove the vehicle last before you set off, not when the light goes on. ## Keeping AdBlue out of the diesel tank when you top up A routine for the day the light comes on, wherever around West Midlands that is. - Not in a rush on the side of Horton Square, not on a slope, not with the motor running: park then switch off properly. - Say "AdBlue" out loud as you unscrew the cap, after finding the AdBlue filler and read it. Silly, perhaps, but it works. - Leave the diesel cap on. If both sit under one flap, check the diesel cap is still closed before you lift the bottle. - Using the bottle's own spout, tip slowly — and stop when it is full or the bottle is empty. - Before starting the vehicle, close the cap and look a second time that the diesel cap never opened off. If at step two or three you find you have already poured into the diesel side, stop there. Step five stays out. ## Already put AdBlue in your diesel tank around Highgate? What follows is a short order of things, starting with not starting the motor. Don't switch the ignition on; on plenty of diesels that alone runs the fuel pump. Topping up with diesel won't thin it: rather than mixing, AdBlue drops to the base of that tank, right where fuel is drawn from. The attendants at Rea Bridge Service Station, Texaco or any forecourt will normally help to push the vehicle clear if you ask. Leave it where it is if you're on your own drive in Highgate. Already started? Pull over once it is safe, then turn off. Leave the Aston Expressway — under 3 miles out of Highgate — at the next junction. Mileage counts — a quick hop across Highgate is a smaller job than heading under 3 miles towards Birmingham — so tell us roughly how far it went. ## What occurs when we get there around Highgate Our technicians come to your car wherever it has stopped, whether that is outside Lift Percy Shurmer, close to Highgate Baptist Church or on your own drive. Our engineers ask what got in, roughly how much, and if it has run, since the replies decide this work and our quote. That quote comes over the phone, before any van leaves. After that: a drain, then a full flush of the whole system. Unlike petrol, AdBlue leaves crystals and eats at some fuel-system metals, and none of it clears out unaided. Hence it matters more. Your filter is cleaned, or replaced where it needs to be; fresh diesel goes in; and your car is tested. Then we start it and check it runs smoothly before we go. Most jobs are finished in roughly half an hour after our technicians arrive, provided your motor has not run — and the pumps our engineers use are fine on a busy forecourt and quiet after dark outside a house. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. It's worth looking at your insurance while we travel to you: misfuelling cover comes with plenty of policies. ## About Highgate itself Highgate is a suburban area in the West Midlands, situated near the River Rea and close to the city centre of Birmingham. Highgate has a relatively low elevation of 109 metres and is located near other nearby places such as Deritend, Digbeth, and Balsall Heath. Highgate is predominantly composed of flat housing and has a population of approximately 9211 residents. Highgate is also relatively far from London, at a distance of 100.1 miles. ## AdBlue drains around Highgate and across West Midlands Highgate is a residential suburb, and our vans that cover it also work the places around it, Digbeth and Balsall Heath among them, across the B postcode area. Quote a postcode that starts B12 0, and our van arrives quickest. Your car stays put. A drive, a lay-by on the way to New Hope Community Park, a side street close to Reverend Peter Stanford: we drain the car where it sits. If you're near a boundary, or somewhere hard to explain like the back of Birmingham Central Mosque, ring and ask instead of assuming. ## Highgate drivers: the short version Before you pour, read the cap. AdBlue in your diesel tank regardless? Leave it switched off then ring 0333 366 0103; Petrol in Diesel drains it where it stands, across West Midlands.