--- title: Petrol in a Diesel Car Black Tar — Next Steps canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/black-tar-pembrokeshire/ location: Black Tar county: Pembrokeshire latitude: 51.748220 longitude: -4.905930 service: Petrol in a Diesel Car updated: 2026-10-06 --- # Petrol in a Diesel Car in Black Tar: What Happens Now Stop. Engine off. Keep the vehicle that way — no moment on, no shifting it at all. Drained then flushed, just where it sits: that's generally all an unrun diesel with petrol in it needs. Whether it remains that simple depends on the minutes to come more than on anything else. Here's the order of things from here, wherever you're in Black Tar. ## Petrol in a diesel? What to do in minute one Work through these in sequence, first. - Pull your keys out. Even the ignition on its own can prime the system, drawing petrol out of your tank to exactly the parts it damages, and so keep it off wholly. - No diesel on top. More fuel in takes away none of the petrol — it only makes you with extra of the same mixture. - Get the car easy to see first — hazards on — if there's traffic going past anywhere near you. - The attendants will generally help you roll it away from the petrol pump. Ask, and move it by hand — not on the engine, even for a few yards. - The first question we will ask is which fuel went in and about how much — and your receipt says both. Hold on to it. On the M4, under 50 miles from Black Tar, the next junction is the location to leave it; elsewhere, the first sensible spot to stop. Do not press on to the services. Then go back to step one. ## Black Tar fuel drain: has your engine run yet, or not? One answer is what everything after this point depends on. If the motor has not run at all: - No place but the tank: that is where that petrol yet is. - Where your car sits is usually where this work happens: a drain, then a flush. - Stage one counts for exactly this reason: it is the best place to be in. If your motor has run, even briefly: - The fuel lines and your filter already hold petrol pulled from the tank. - On a longer run it has got to your high-pressure pump as well as the fuel injectors. - The farther it went, the larger this job — the lines, your filter, and now and then more besides. The line falls there because diesel protects the high-pressure fuel pump and your injectors on its way through them — and petrol does not. A tank of petrol, left still, hurts nothing. Petrol being pumped is grinding down the parts that move the car. ## What to have ready when you call about petrol in a diesel from Black Tar Whether the technician goes round or finds you comes down to a little preparation. - SA62 4 and the remainder of the postcode makes the best way to begin telling us where you are. - Wherever you have pulled up, the road's name helps — whether that's Rectory Road or somewhere else — and so does the name of a car park. - Describe a car park by what it serves — the one at Co-op Food, for instance — and it's much quicker to find. - Make and model of the car, and the fact it is a diesel. - Tell us which got in — petrol or AdBlue — because AdBlue is a separate job, with a page of its own for Black Tar. - The amount: the receipt's litres, or otherwise how long you had the nozzle in. - If it has run, how far and how heavily — as well as whether it's run at all. - The owner may have to authorise this work under some hire or company contracts — so it's faster to settle whose car it is before we arrive. Then ring 0333 366 0103. If it can wait — your car is at home with going nowhere — works as well. ## Whilst you wait for a fuel drain in Black Tar Help, however well meant, is what does the damage whilst you wait. So stick to these. - Where your car has stopped decides where you wait. Exposed: away from it, away from the traffic. Safe: with it. Either way, safety ahead of your car. - Nobody — however helpful — starts it, whether to see if it runs or to move the car a short way. - Anything from the boot, oil meant for two-strokes or injector cleaner: no additive lifts the petrol. - A DIY drain leaves your fuel that has already gone beyond your tank, and siphoning petrol by the road is dangerous besides. - Not for your radio, not for your windows: your ignition stays off. ## When the van arrives: your fuel drain, step by step - Three questions. What went in, how much, and whether it's run. The replies decide the job, which is why the quote comes after them and not before. - Emptying it's how that blend gets taken out of the tank. - If it ran, your lines are holding petrol that has moved beyond the tank — so they're rinsed. - Your filter is seen to. Cleared, or replaced where your car has a usable one. - The fuel system is primed with clean diesel. - The start-up. With fresh diesel in and your system bled, it's started and tested to confirm it runs smoothly. Until it runs on new diesel, our engineers remain with it. It is very uncommon for a car caught early to be left with permanent damage, and normal use starts again at once. ## After the fuel drain: back on the road around Black Tar - Started on clean diesel, it needs nothing special of you. Simply drive normally. - Pull over and ring us back if anything seems wrong early on — a light on the dash, smoke from the exhaust, an idle that runs rough, or a throttle with a dead spot. - Hold on to the paperwork. A hire company, a fleet manager or an insurer may ask what was done. - Next time, go by the petrol pump's label instead of the colour of its handle. ## About Black Tar itself Black Tar is a small coastal locality in Pembrokeshire, situated near the villages of Llangwm and Guilford, with detached housing being the predominant type of accommodation. Black Tar sits at a low elevation of around 12 metres, close to the sea, and is located approximately 17.9 miles from St Davids. Black Tar is part of a wider area of scattered settlements and rural landscapes in western Wales. Black Tar has a small population of around 500 people. ## Fuel drains across Black Tar and nearby Llangwm, Guildford and Guilford are served by the same vans that take petrol in diesel calls in Black Tar — and so is most of Pembrokeshire beyond. Somewhere tricky to describe, or close to a boundary? Asking beats assuming — ring. ## Ring, and leave the car off — petrol in a diesel across Pembrokeshire Step one is the whole of that: engine off, keys out, receipt in your pocket. From there Petrol in Diesel takes over, on the forecourt, by the roadside or on your driveway.