Petrol in a Diesel Car in Kirk Sandall: How Worried Should You Be?
Provided it hasn't been started, you can worry far less than you likely are. Until the ignition primes your pump, your starter turns, or the vehicle is driven, petrol in a diesel tank just rests there and does no harm. Which makes the truthful reply to that first Kirk Sandall question — "have I ruined it?" — usually no. Leave your motor off then call Petrol in Diesel — that is how you keep it that way. What petrol really does to a diesel, how to gauge how far it's gone, and how to stop it from happening again: that is the rest of this page.
Petrol in a diesel: what does it do to the motor?
Two jobs fall to diesel on its journey round a motor. Lubricating comes before burning; it does both. Extremely fine gaps go into your injectors and the high-pressure fuel pump, and only your diesel running through keeps their surfaces from grinding together.
The second job petrol doesn't do at all, and the first it does badly. It's runnier than diesel and takes away the lubrication the fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
The shape of the issue is clear once you put those together. The damage is done by circulation, not by contact. Any tank with petrol in it is a fuel fault. Once your pump has been running on that petrol, a mechanical issue has begun: anything shed by a pump that's grinding travels onward to your injectors with your fuel.
How serious is petrol in a diesel? Four scenarios our engineers see in Kirk Sandall
Filled but never started — the best it gets. On a forecourt, and genuinely only there, that petrol is still limited to the tank — since anywhere else the vehicle was driven to get to it. The job is emptying and purging on the spot.
A brief spell of running, or merely the ignition on. The system has been bled, and so petrol has left that tank and got to the fuel filter and the fuel lines. Still generally straightforward: drain, flush, and the filter dealt with.
Driven a couple of miles. Now your pump has spent those miles working on thinned fuel. Tank, lines, filter, then fresh fuel put through the entire circuit: that's the work, and the way the car was driven counts as much as the mileage. Driving the kids to Kirk Sandall Junior School is one sort of trip. Getting as far as Doncaster, under 5 miles away, makes a very different task — as does any miles on the M18, under 3 miles from Kirk Sandall, with the motor working hard the whole time.
Driven on till it protested — knocking, smoke, an uneven idle, a dead throttle. The fuel isn't behaving like diesel any more, and your motor is saying so. Pull up on the spot — on the verge on Brecks Lane, at the kerb, down a side road — and do not move it again. A car stopped soon very seldom has permanent damage, since the drain and the flush, which still come first, take care of it.
Kirk Sandall motorists and the petrol in a diesel myths they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A bigger tank of the same mix is all you get, because topping up removes nothing. A diesel fuel system does not tolerate petrol by percentage in the way that guidance presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Finer components and higher pressure are how a newer diesel runs its fuel, and that makes the protection matter more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools people. A petrol motor fed diesel generally won't run, and so the motorist stops and the harm stops with them. While your pump grinds, a diesel fed petrol usually starts, idles and drives away as if nothing has happened. Fine and running are not the same thing.
Myth: "Add some two-stroke oil and drive it home." It's an outdated workaround for a different problem. None of what petrol diluted gets put back by it — and afterwards, the tank still holds that petrol.
Myth: "Drain the tank yourself and you are sorted." After the engine has run, some of the petrol is no longer inside the tank: it is in the filter and your lines, and it goes right back through the pump on your next start. It's also really hazardous to drain petrol into a can at the roadside.
Petrol in a diesel: how does it occur?
A careless moment is seldom the cause, and nobody means to do it. A diesel nozzle generally won't fit a petrol car, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error simple, and only in one direction.
The moment routine stops matching your car is the moment it takes place. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Filling up in a hurry on the way to the nearest station, with a train to catch. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Throw in a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up in Kirk Sandall: preventing petrol in a diesel
- A green handle for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Trust the label on the pump, not the colour.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of vehicles print the fuel there.
- Label your key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- It seems daft and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- While you are thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to block a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop reading the pump.
- The moment you realise, stop: less petrol in the tank means a thinner blend. What to do next does not change, though — still don't fire it up.
Petrol already in a diesel in Kirk Sandall? Begin here
In that case, there is only a short order of things. Don't crank it, and do not switch the ignition on. Yet at the forecourt, at Tesco or anywhere else? Ask the staff to help you push the vehicle away from the pump. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate fault — Kirk Sandall has a page just for it.
Kirk Sandall petrol in a diesel jobs: why one costs more than another
The four scenarios above are four different jobs, so no single quote for this would be fair. Chiefly, your cost moves with which one you're in. Two things follow that: the petrol that went in as a proportion of what that tank takes, then the place your car is in and whether a technician can get to it safely.
That is why our engineers ask three queries before quoting instead of after: what went in, how much, and if it has run. The replies change a range into a straight figure.
About Kirk Sandall itself
Kirk Sandall is a village in South Yorkshire, situated near the town of Doncaster and close to the villages of Long Sandall and Edenthorpe. Kirk Sandall lies in a low-lying area of the Yorkshire landscape, with an elevation of around 11 metres, and is characterized by its semi-detached housing stock. Kirk Sandall is located approximately 3.8 miles from Doncaster and 147.4 miles from London, making it a commuter-friendly location.
Fuel drain cover across South Yorkshire, Kirk Sandall included
Long Sandall, Edenthorpe and Barnby Dun are among the spots around Kirk Sandall that the same vans work, answering petrol in diesel call-outs across Kirk Sandall's DN postcode area. The vehicle does not need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump around Kirk Sandall, right now?
The best place there is, then — that's where you are. Switched off it remains; then phone.