--- title: Explained: AdBlue in a Diesel Tank Pathhead canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/pathhead-midlothian/ location: Pathhead county: Midlothian latitude: 55.867410 longitude: -2.967360 service: AdBlue in a Diesel Tank updated: 2026-10-02 --- # Why It Occurs and How to Prevent It: AdBlue in a Diesel Tank in Pathhead Stop reading a minute when the diesel tank already has AdBlue in it: ignition off, motor off, then call 0333 366 0103. Caught before your motor runs, it's normally a drain and a thorough flush, done where the vehicle is in Pathhead. If you're reading before it has happened, the remainder of this page is about why it happens and how to make sure it does not. ## Why does AdBlue in a diesel car need its own filler? Many modern diesels on the roads around Pathhead and Chesterhill carry two liquids, not one. Diesel goes to the motor. AdBlue's own tank holds it, and from there it is sent to your exhaust, and there a spray treats the fumes. Each tank has its own filler. Other cars keep the AdBlue filler in your boot or under the bonnet; plenty of others have the two together under one flap. Diesel goes in on each forecourt visit, week in, week out. The AdBlue side is topped up far less often, normally from a bottle, and usually by a person who has to stop and think where it goes. The mistake grows in that gap between the two. ## How does AdBlue in the diesel tank occur around Pathhead? It's rarely carelessness. Three things tend to line up. Hurry follows from the warning. Your car warns you as AdBlue runs low, and a dry tank sends the vehicle into limp mode — so the top-up happens in a rush, before work on a drive off Oxenfoord Avenue, or on the way home in the car park outside The Foresters. Unfamiliar motors are next, too. Hire cars, new cars and company vehicles put their fillers differently, and habit reaches for the cap it 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, so nothing stops the pour after it has started. Dewartown or the middle of Pathhead: it is the same few seconds either way. ## Which filler is for AdBlue, and which for diesel? Be it a Pathhead forecourt or a driveway out in Newlandrig, spend a couple of seconds on these before anything is poured in. - Where it sits misleads; the cap does not. AdBlue caps tend to be blue or bear the word "AdBlue" — diesel caps usually do not. - Check the size: the smaller filler neck is, on many motors, the AdBlue one. - Open the filler flap and look for a label — plenty of vehicles mark what goes in which filler right there. - In your boot or under the bonnet: that's where your filler sits if it is not by the diesel cap, and the handbook says which. - The previous driver knows. Check when you pick up a hire car or fleet car — at Gorebridge's car park, perhaps — not when the light appears. ## AdBlue top-ups that never reach your diesel tank On the day the warning appears — wherever you are across Midlothian — a routine to follow. - Pull in somewhere level, engine off, with time to spare — never hurried on the side of Oxenfoord Drive. - Daft as it sounds, speaking "AdBlue" aloud while you unscrew the cap works — after you have located your filler and read it. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — and leave it on. - Stop when the tank is topped up or the bottle runs dry; until then, pour gently through the built-in spout. - Before starting the car, close the cap and look a second time that your diesel cap never opened off. Spot at stage two or three that it has already gone into the diesel side? So stop just there. Skip step five entirely. ## Put AdBlue in your diesel tank around Pathhead already? The short order of things, beginning with not starting the motor. On many diesels your ignition alone runs the fuel pump, so do not switch it on. Do not top up with diesel to thin it: AdBlue does not mix with diesel, it sinks to the bottom of the tank, where your fuel is pulled from. On a forecourt — Esso, BP or another — the attendants will normally help roll your car away, when you ask. Your own driveway around Pathhead is where it stays. Stop as soon as it is safe then switch off, if your motor has already run. Leave the M8 — under 15 miles out of Pathhead — at the first junction. About how far did it go? Crossing Pathhead is smaller a job than a run of under 15 miles towards Edinburgh, and so tell us. ## When our engineers turn up around Pathhead, what occurs? The van comes to your car anywhere it has come to rest — your own drive, beside Pathhead Village Hall, or by the local primary school. Both the work and our price depend on three replies — what liquid, what amount, and if it's run — so our technicians ask. During the call itself, you hear the price — ahead of anything else. Next: draining, then a thorough flush of the whole system. More than with petrol, it counts with AdBlue: the crystals form, some metals are attacked, and none of that washes away unaided, however long it sits. The filter is cleaned, or replaced where it needs to be; clean diesel goes in; and the vehicle is tested. The motor is started next and checked to make sure it runs properly, all before we leave. With pumps fine on a busy forecourt and quiet enough for use outside a house at night, most jobs where your engine has not run need about half an hour after our technicians arrive. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. Plenty of insurance policies include misfuelling cover, so it's worth checking yours while we are on the way. ## About Pathhead Pathhead is a village situated on the riverside in Midlothian, with a mix of semi-detached housing and other residential properties. Pathhead sits at an elevation of 156 metres, near the towns of Dewartown and Edgehead, and is located approximately 10 miles from Edinburgh. Pathhead has a population of around 797 people, and its location near the Scottish capital makes it a commuter base for those working in Edinburgh. Pathhead is also close to other nearby places, including Crichton. ## AdBlue drains around Pathhead, and Midlothian beyond Pathhead is a village, and the teams that cover it also work the places near it, Edgehead and Crichton among them, across the EH postcode area. Our van gets to you fastest with a postcode starting EH37 5. Shifting the car is not necessary. Our engineers drain it where it is — a side street close to Oxenfoord Castle, a lay-by on the way to Ford Glen, a driveway. Tricky to explain, like the back of Cranstoun Church? By a county line? Checking is better than assuming, so ring. ## Pathhead people: the short version Tip no AdBlue until you have read the cap. If AdBlue has gone in the diesel tank regardless, leave it off then call 0333 366 0103. Petrol in Diesel empties it where it stands, anywhere across Midlothian.