--- title: Next Steps: Petrol in a Diesel Car Mainstone canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/mainstone-devon/ location: Mainstone county: Devon latitude: 50.414250 longitude: -4.085550 service: Petrol in a Diesel Car updated: 2026-10-01 --- # The Next Steps, in Order: Petrol in a Diesel Car in Mainstone Pause, then leave the engine off — not on, and not for a moment to move the vehicle. Petrol in a diesel that has not been run is usually a drain plus a flush, done right where the car stands, and what you do in the next few minutes decides that more than anything else. From now on, step by step, wherever you are in Mainstone: ## Engine off: minute one with petrol in a diesel First, these — in this order. - The ignition off, keys out. Switched on, your ignition can prime your system — and priming is what draws petrol out of your tank towards the parts it harms. - Don't top it up with diesel. Adding diesel removes nothing. You are left with a bigger tank of the same mix. - Hazard lights on. If you are at all close to moving traffic, make the car easy to see before you do anything else. - Off the pump by hand. On a forecourt, ask the staff to help you roll the vehicle clear of the petrol pump. Do not fire it up to shift it, however short the way. - Hold on to the till receipt. It says which fuel was put in plus about how much, which is the first thing we'll ask. On the M5, under 50 miles from Mainstone, the next exit is the location to come off; anywhere, the first sensible location to stop. Do not press on to the services. Then go back to stage one. ## The fork in every Mainstone fuel drain: has it run yet? What comes next rests on one answer, and just one. Not run, not even once: - Only the tank has petrol in it so far. - Where the car sits is usually where this work is done: a drain, then a flush. - Stage one counts for exactly this reason: it's the best position to be in. Run at all, however briefly: - Out of your tank, past the fuel filter, into your lines: that is how far the petrol has travelled. - Your high-pressure pump as well as your injectors get it on a bigger run. - Miles is what makes it a bigger job: flushed lines, a filter seen to, and at times further work. Diesel keeps the high-pressure pump and the fuel injectors protected as it goes through them. Petrol gives them nothing, and that is why the line is drawn there. In your tank, left alone, petrol does no harm. Pump the petrol, though, and it grinds down the very parts that move it. ## Before you call about petrol in a diesel in Mainstone: what our technicians need A little planning is the difference between a technician that finds you and a van that circles. - PL6 8 plus the remainder of the postcode is the ideal way to begin telling us where you are. - A road name is a help: Earls Wood Drive, say, or whatever street you have stopped in. A car park does the trick too. - What a car park serves is the easiest way to find it, and so mention the landmark — such as the one outside Asda. - The vehicle. Make, model, and that it is a diesel. - Petrol or AdBlue? Tell us which. They are separate jobs, and AdBlue has a separate Mainstone page. - How long the nozzle was in, or the litres on your receipt — either tells us how much. - If it's run, how far and how heavily — and whether it has run at all. - Sort who owns the car before we get there: some hire or company agreements want the owner to authorise the work, and doing it quicker first. Then call 0333 366 0103. If it can wait — the car is at home with going nowhere — does the trick as well. ## Mainstone fuel drain on its way? Whilst you wait The wait is where kindly meant help does the harm. Hold to these. - Your safety comes before the vehicle. Somewhere unsafe? Get away from the traffic and wait away from it. Fine where it sits? Wait with it. - No one — however kind — starts it, whether to see if it runs or to move the car a short way. - No additives. Two-stroke oil, injector cleaner, something from your boot — none of that gets the petrol back out. - Draining it yourself is out: a can of siphoned petrol on a verge is a danger, and your fuel beyond your tank remains put anyway. - Ignition remains off. Even for the radio or your windows. ## When our van gets there: your fuel drain, step by step - Three queries. What got in, how much, and if it has run. The replies decide this job, which is why the quote comes after them and not before. - Next your tank is cleared, so the contaminated fuel comes out. - The fuel lines are flushed. If it ran, the petrol has shifted beyond your tank, and the lines are holding it. - The fuel filter is seen to. Cleared, or replaced where the vehicle has a workable one. - Clean diesel goes in, and your system is primed. - Our engineers start the car only after clean diesel has gone in and primed your system, then make sure that it is running properly. Only once it is running on clean diesel do our technicians head off. The car goes back to normal driving right away, and permanent damage is very unusual when it has been caught quickly. ## Once your fuel drain is done: driving around Mainstone again - After it has been started on fresh fuel, there is nothing special to do: drive normally. - Keep an eye on the first miles. A warning light, smoke, a rough idle or a flat spot under the throttle means pull over and ring us back. - The work may matter later with a hire company, an insurer or a fleet manager. Keep your paperwork. - Next time, check the pump. The label, not the colour of the handle. ## About Mainstone and where it is Mainstone is a suburban area located on the outskirts of Plymouth in Devon, sitting at an elevation of 97 metres near the River Plym. Mainstone is characterized by its semi-detached housing stock and is situated close to nearby places such as Estover, Leigham, and Glenholt. Mainstone has a population of approximately 1401 residents and is about 3.9 miles from Plymouth city centre. Mainstone is also relatively distant from London, at around 188 miles away. ## Fuel drains round Mainstone and beyond Most of Devon gets the same teams as Mainstone for petrol in diesel call-outs, Estover, Leigham and Glenholt included. Ring and ask instead of assuming if you're somewhere hard to explain or close to a boundary. ## Ring, and leave the vehicle off — petrol in a diesel around Devon Keys out, engine off, the receipt in your pocket: that is stage one done. The rest is for Petrol in Diesel, wherever your car is — forecourt, roadside or driveway.