--- title: Explained: AdBlue in a Diesel Tank Olchfa canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/olchfa-swansea/ location: Olchfa county: Swansea latitude: 51.620020 longitude: -4.006420 service: AdBlue in a Diesel Tank updated: 2026-10-05 --- # AdBlue in a Diesel Tank in Olchfa: How It Occurs and How to Prevent It AdBlue already in the diesel tank? In that case set this page aside a moment, keep your ignition and motor off, then ring 0333 366 0103. Around Olchfa, catching it before the motor turns usually leaves a drain and a full flush where it stands. Nothing happened yet? Below, the page explains the reasons it happens and the how to avoid it for good. ## Two fillers, two tanks: AdBlue in a diesel car Diesel feeds your motor — but many modern diesels driven about Olchfa and Ty-coch carry another fluid too. AdBlue goes to the exhaust, where it is sprayed into the gas to clean it, and it lives in a tank of its own. Different tanks, different fillers. Other cars keep the AdBlue filler in the boot or under the bonnet; a lot of others have both together behind one flap. Filling your diesel side at the petrol pump goes on constantly. Someone who has to stop and think where it goes usually tops up the AdBlue side, from a bottle, and much less commonly. The slip lives in that gap. ## Olchfa: how AdBlue in your diesel tank occurs It's seldom carelessness. Three things tend to line up. The warning comes first. As AdBlue runs low your car tells you, and if it runs out completely, the car drops into limp mode. So the top-up is done in a hurry: on a driveway off Ffordd yr Olchfa before work, or in the car park at Hen Dderwen on the way home. Then your car is new. A hire car, a new vehicle or a company car puts the fillers where your last one didn't, and the hand reaches for the cap it would have used on the old one. Third, the bottle fits: a diesel filler or AdBlue one, it goes in just as easily, and after the pour starts, nothing stops it. Penyrheol or the heart of Olchfa: it is the same few seconds in both. ## The AdBlue filler and the diesel filler: telling them apart Before you pour anything, whether on a driveway in Sketty or a forecourt around Olchfa, check these. They take a few seconds. - Read the cap rather than going by position: AdBlue caps are often blue or marked "AdBlue", and diesel caps usually aren't. - On many motors, the size gives it away: AdBlue has the smaller filler neck. - Open the filler flap and check for a label — plenty of vehicles show what goes in each filler right there. - Cannot find it next to your diesel inlet? In that case check below the bonnet or in your boot — the owner's manual will say where. - Picking up a hire or company car, say at the car park at Gowerton? Check with whoever drove the car last before you set off, rather than when the light goes on. ## Keeping AdBlue out of your diesel tank when you top up Wherever around Swansea the light comes on, here is a routine for the day. - Not in a rush on the side of Olchfa Lane, not on a slope, not with your engine running: park then switch off properly. - Daft as it sounds, saying "AdBlue" out loud as you unscrew the cap does the trick — once you've located the filler and read the cap. - The diesel cap stays on. When the two share a flap, make sure it is closed before the bottle comes up. - Tip slowly, using the bottle's own spout. Stop when it's full or when the bottle is empty. - Shut the cap, then look once more — confirm the diesel filler remained closed throughout. After that, start the vehicle. Stop there if you find, at stage two or three, that you've already poured into your diesel side. Do not go on to stage five. ## AdBlue in the diesel tank already, around Olchfa? Don't start your engine: that's how the short order of things starts. The fuel pump runs on plenty of diesels as soon as your ignition is switched on — and so leave it off. Diluting it with extra diesel won't work, since AdBlue sinks to the bottom instead of blending — and that's where your fuel is pulled from. If you're at a forecourt, whether it's the Texaco or the Esso, ask the attendants to help roll your car away from the petrol pump. Leave it where it is if you're on your own drive in Olchfa. Stop as soon as it is safe and switch off, if the motor has already run. Olchfa lies under 5 miles from the M4; on it, use the next junction. Tell us about how far it went: a run towards Swansea, under 3 miles away, is a bigger job than a short hop across Olchfa. ## Our arrival around Olchfa, and what takes place next Wherever the car has stopped, be it by the local primary school, beside School Library or on your own drive, the van comes to it. We ask what was put in, roughly how much, and whether it's run, since the replies determine this work and the price. On the call itself, you are told the quote — ahead of dispatch. Emptying that tank comes next, then a thorough flush of the system. With AdBlue that counts more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own. Filter flushed or, where it must be, replaced; fresh diesel in; and then a check of the car. Then our engineers start the car and make sure it runs properly before we go. Using pumps safe on a working forecourt and quiet enough to use outside a house at night, most jobs where the engine has not run need roughly half an hour once we are there. Paying is on the day, not upfront, and you receive the documents an insurer asks for: an engineer report and a VAT invoice. Wrong-fuel cover is part of plenty of insurance policies — and so make use of the wait to look at yours. ## About Olchfa, for a moment Olchfa is a suburban area located on the outskirts of Swansea, situated near the coast in south Wales. Olchfa sits at an elevation of 88 metres, overlooking the surrounding landscape and nearby communities such as Penyrheol and Killay. Olchfa is characterized by its predominantly flat-type housing, which is typical of many suburban areas in the region. Olchfa is close to the city of Swansea, being only 2.8 miles away from the city centre. ## Olchfa and Swansea: AdBlue drains across the area Being a residential suburb, Olchfa has the same vans as nearby areas — Carnglas, Killay — all the way across SA postcodes and the surrounding area beyond. Quickest of all: give a SA2 7 postcode for the van. There's no need to shift your car. Anywhere it stands — near Sports Hall, on a lay-by en route to Hendrefoilan Woods, on a drive — that's where it is emptied. Guessing doesn't help behind Sketty Park Community Centre, close to a border, or anywhere awkward to pin down; phone and ask. ## The short version for Olchfa people Always, the cap; after that, the pour. Even so AdBlue in the diesel tank? Petrol in Diesel can drain it where it is, anywhere around Swansea: keep it off then ring 0333 366 0103.