--- title: Drain Petrol From a Diesel Car — Southway canonical: https://www.petrolinadieselcar.co.uk/petrol-in-diesel/southway-devon/ location: Southway county: Devon latitude: 50.428200 longitude: -4.129460 service: Petrol in a Diesel Car updated: 2026-10-08 --- # Put Petrol in a Diesel Car in Southway? With your tank still carrying the fuel and your engine not yet turned over, nearly every job takes only a drain, so keep the engine off. That result is settled in the minutes immediately after filling up, and not by the amount that went in. Across Southway and the remainder of Devon, Petrol in Diesel drains the car and flushes it where it is, whether at a roadside, on a drive or at a forecourt. Our engineers will show you what the next move will be. Call us — this happens ahead of anything else. ## Petrol in a diesel: what to try now - Don't crank it — and never trust it if it fires up. That is the thing drivers have wrong about petrol in a diesel specifically. A petrol motor filled with diesel typically just won't run, so the driver stops and the wear halts with them. A diesel filled with petrol typically starts, idles and drives off without complaint for a couple of miles. It isn't all right. It's grinding the fuel system while you drive. - Leave the ignition alone as well. Diesel does two jobs: it combusts, and before it ignites it protects the high-pressure pump and the injectors. Petrol manages the first and not the second. Turning the ignition on is frequently enough to prime the system, which moves the petrol out of that tank then into precisely those components. - Don't add diesel on top to dilute it. A diesel fuel system will not cope with petrol by percentage the way that guidance presumes, and topping up clears nothing — it just hands you a bigger tank of the same blend. The type makes no difference either: super unleaded is just petrol. - Stay put if it is sensible to. Hazards on, motor off, keep it. Wherever you have stopped — the verge on Southway Drive, anywhere — an awkward location for us is better than a started diesel, and nothing is easier for us to sort out than a vehicle that never shifted. - Before you ring, have your whereabouts. Anything nearest to you with a label on it, plus a postcode that starts PL6 6 — that is what settles whether our van shows up or circles. - Ring 0333 366 0103. Say what was put in, about how many litres, plus whether the motor has started. Those three answers determine your whole visit. ## Forecourt drains for petrol in a diesel Much of this job begins at a forecourt, which means a big part of that gets done on site. If you're still on the forecourt at Tesco, that's usually where the drain happens — we work on garage forecourts regularly, with the owner's permission. The forecourt is the single setting it is stopped before the motor has run. We can still put it right where it stands, even away from the pumps. In a car park, on a drive or in a lay-by, the car has been switched on and driven there, and that sucked fuel through the filter then into your high-pressure pump, all the way from that tank. None of that is a catastrophe, but the flush then has to go past your tank to your lines and the filter, and the few seconds between checking the receipt and going for the keys are what determine that. Roll the vehicle out of the way if the staff offer, and they usually will. The next customer gets through the pump, and that is worth doing. Cranking it just to roll four car lengths is not. How much fuel the pump has pulled is what we're actually asking — not how long ago any of that was. So the phone call our technicians like runs like this: diesel Renault Clio, some litres of unleaded, a couple of miles done, now turned off at Aldi. ## Do our engineers reach your end of Southway? Derriford, Glenholt, Belliver, Woolwell, Widewell — all of them on the rounds that bring us across to Southway too, a residential suburb. Our technicians still come. Those names above are just the nearest neighbours, and a page is there for most locations across Devon, and so an absence from the list is not an absence from the coverage. Call us and enquire rather than assuming — borders especially, and anywhere your satnav tends to misread. The patch the page covers sits on this map. We operate roadside, on forecourts, on driveways and at car parks across all of that, and the car never needs to move to us. Twenty to nine. At the gates of Beechwood Primary Academy. Late already, and the receipt in your hand says unleaded. Put the hazards on, leave your ignition alone, and phone. You could think three miles is nothing, in the Skoda Octavia or anything else — except that fuel is supplied on demand, and a run taken in a rush demands a great deal of that. ## Roadside breakdowns across Southway The opportunity to pull over somewhere sensible doesn't fall to everyone. Hazards flashing in a lay-by somewhere, or stopped on the verge of Rockfield Avenue as you realised after setting off — we take that call so often that it's the usual kind. Wait beside your car when it's wise to wait inside, and out of it if it isn't. Don't start up the motor to nurse the vehicle somewhere handier — a diesel running on petrol will usually oblige, and every mile it obliges for is pulling that blend further into the system. Pressing on causes the car far more harm than a technician driving out to an awkward spot, and that is no problem for us. ## A few miles on petrol in a diesel: now what? This is where your M5 matters, under 50 miles away from Southway. A drop in power, an uneven idle, smoke: those are the symptoms when they arrive, instead of a neat stop — and a misfilled diesel will usually take you onto it and some way along before anything feels wrong at all. The first sensible exit is the one to take. Turn off there, and leave the restarting alone. On a longer run — anything approaching the under 5 miles to the nearest city — take it the contamination has been through your filter, the pump and the injectors, and mention it when you ring. It affects what our engineers bring. ## Where's Southway? Southway is a suburban area located on the outskirts of Plymouth in Devon, sitting at an elevation of 108 metres. Southway is characterized by its predominantly terraced housing and is situated near the nearby places of Derriford, Glenholt, and Belliver. Southway is close to the coast and is approximately 4.1 miles from Plymouth, making it a residential community with access to the city's amenities. Southway has a population of around 5355 residents. ## What happens when we get to you around Southway - Our engineers ask first, price after. What was put in? How much? Has your engine run? Those answers alter what the work really is. - The contaminated mixture is pulled from your tank. - Lines rinsed, filter cleared. Whatever is left later isn't the thing that created the problem. - Priming follows, once new diesel is in. - It's started with new diesel in it, and our engineers make sure that it's running properly. Your car is then ready for you to drive away. Lasting damage is very uncommon when it has been caught quickly, and because all of it is done where the car is, it never has to go to a garage. Draining the Mercedes E-Class, changing the filter where there is a usable one, purging the lines, putting fresh fuel through the whole circuit: that is the job, and it is shaped by the worst of that resting in the lines instead of in the tank by this point. Three things help when you ring from near Church of the Holy Spirit — which side the filler is on, whether our van can pull up next to without blocking the road, and whether your engine has run since you filled up. On-street is the commonest spot our technicians work, and so the location itself is hardly ever the issue. A narrow parking space trumps a vehicle driven somewhere more handy. ## AdBlue in a diesel tank around Southway is a different problem The problem is not the same, though the opening rule is — do not fire it up — if what got in was AdBlue instead of petrol. The lubrication a fuel system depends on gets stripped away by petrol, which weakens your diesel. Urea dissolved in water, AdBlue, and in a diesel tank that causes rust and residue. Both are ours. There's a separate Southway page for AdBlue removal, with the details on it — including the reasons it often turns out to be the worse of the two. Authorisation first, where there is a hire firm or a company behind the car — some contracts require it, and settling that beforehand saves a great deal of time later. After that, phone us about the diesel Audi A3 close to St Thomas More. You'll not know how full your tank was. Hardly anyone does, two days into a motor, and it gets worked out on the spot all the same. We ask since the damage petrol does in a diesel is proportional: a few litres in a nearly empty tank make a much stronger mix than the same few in a full one, and since petrol is engineered to resist igniting under pressure, which is exactly what a diesel relies on, the stronger it gets the more the motor knocks and smokes and flattens off. ## What a petrol-in-diesel drain costs around Southway What shifts the figure is listed below, because this job isn't one job and our engineers cannot frankly put a single price on this page. - Started? Driven? Either answer counts more than anything else on this list. - The tank's capacity, set against how much of the wrong fuel got into it. - Whether it was unleaded or AdBlue. - Whether our van can safely get to your car and work on it, which depends on where the car is. Tell us what the vehicle is, how much went in, and whether the engine has run. A straight answer comes back, not a range. Not time-critical, with the vehicle at home and going nowhere? Then does this job. A few streets, then it stopped. Throttle dead, idle lumpy, and your diesel BMW 5 Series is parked up by Derriford Church. Your engine isn't giving up — that softness is fuel that will not build pressure. There is no light on the dash for it, and so vehicles like yours normally get driven a second time before anybody picks up the phone. Please don't. Off, then ring us. ## Southway drivers ask us these about petrol in diesel ## I'm on a forecourt around Southway. Can you drain it here? A big portion of this work gets done there, so yes. Tell us which one you are at when you ring and we will tell you if our technicians can work there. With the station's permission our engineers work at Texaco and the other forecourts around town regularly. ## A couple of litres of petrol in a diesel — too much? It depends on the ratio instead of the litres, and a lot more on whether your motor has run. What determines how much work is needed is if that mixture has been sucked through the fuel system — since although five litres in a nearly empty tank is a separate case from five in a full one, either way that is the question. ## I drove it after putting petrol in my diesel. What now? Turn off somewhere sensible, then keep it that way after you stop. Driving is what moves the trouble from that tank into the pump and injectors — but it's salvageable far more commonly than motorists expect, and the single most valuable thing you can do now isn't restart it. ## Will a fuel drain void my warranty? It isn't an alteration, and so a drain and flush carried out correctly does not cancel a manufacturer's warranty. Running a diesel on petrol is the thing likelier to cause an argument with one, which is another reason to leave the car turned off. ## Could I put some two-stroke in and just drive? Two-stroke oil solves a distinct issue, and an old one at that. Nothing it does puts back what petrol thinned. No. The tank still has petrol in it afterwards, and your pump still has to put up with it. ## Main dealers and petrol in a diesel There's no need to bring it to a main dealer, because our engineers drain and flush your car wherever it is. ## Standing next to it? Switched off is the way it stays. Already driven it? Then stop somewhere sensible, turn off, then let it remain that way. Cold, stationary, going nowhere: that is the best position to be in. Drivers fear this a lot more than they need to. Mobile fuel draining around Southway and across Devon — at the kerbside, on the forecourt or at home.