Earswick: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, if it has not been started. Till the ignition primes your pump, the starter cranks, or the car is driven, petrol in a diesel tank simply waits there and does nothing. Which means the honest reply to that first Earswick query — "have I wrecked it?" — normally no. To leave it that way, phone Petrol in Diesel then leave the engine alone. The rest of this page covers what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you a second time.
The engine and petrol in a diesel: what happens
On its way through a motor, diesel has two tasks. Before it burns, it lubricates — then it burns. Your high-pressure pump and the injectors are designed to extremely fine gaps, and your diesel passing through them is what keeps those surfaces from wearing down against one another.
Of those two jobs, petrol handles the first poorly and the second never. It is runnier than diesel and removes the lubrication the system hinges on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the rattling comes from.
Together, those leave the shape of the problem clear. It's movement that causes the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. Once your pump has been working on that petrol, a mechanical issue has begun: anything shed by a pump that is grinding travels downstream to the injectors with your fuel.
Four situations we see in Earswick: how serious is petrol in a diesel?
Filled up, and never started: no case is better. Just that tank has petrol in it, and so the task is draining your tank and purging the fuel system where your car stands. This scenario can only really take place at a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a brief start. Once primed, the fuel system has drawn petrol from the tank up to the filter and your lines. Still generally straightforward: drain, flush, and your filter dealt with.
Those few miles on the road meant your pump running on fuel thinned by petrol throughout. How hard your car was driven matters as much as how far, and the work covers your tank, the fuel lines, the fuel filter and clean fuel through the whole circuit. Driving the kids to Ralph Butterfield Primary School is one sort of trip. Very different a second time: a trip to York, under 5 miles away, or any distance on the A1(M), under 15 miles from Earswick, where the motor never stopped running hard.
Driven on till it complained — knocking, smoke, an uneven idle, a soft throttle. The fuel is not acting like diesel any more, and your motor is saying so. Stop wherever you are — the verge on Strensall Road, a lay-by, a side street — and leave it there. What comes first is still the fuel drain and flush-through, and that takes care of it, with lasting damage very unusual when a car is stopped soon.
Earswick people 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 will be." A fuller tank of the same mix is all it gives, since topping up removes nothing. That advice presumes a diesel fuel system handles petrol by percentage. It does not.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." Protection counts more on current diesels, not less, since their fuel runs through smaller components at higher pressure.
"It starts, it drives, and so there is no harm" — the myth that catches more motorists than any other. A petrol motor fed diesel usually won't run, and so the driver stops and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while the pump wears. Being able to run isn't the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate problem. None of what petrol thinned gets put back by it — and later, that tank still contains that petrol.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in your filter and lines, waiting to go right back through your pump on the next start. Emptying petrol into a can at the roadside is also truly hazardous.
Why petrol in a diesel happens so easily
Carelessness is rarely the cause, and no one means to do it. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol car at all. So the error runs one way.
It takes place when routine and the vehicle stop matching. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps arranged differently. Racing for a train outside York and filling up en route. A new-to-you diesel Renault Clio, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. Throw in a back seat full of children, a phone call or rain, and the hand takes over.
How to prevent petrol in a diesel at your next fill-up in Earswick
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what counts.
- Plenty of cars state the fuel type inside your filler flap or on the cap, so check there on your first fill in any car you don't know.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, for a home with one of each.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car gets its first tank. It sounds silly. It works.
- Mistakes like this are straightforward to make while your mind is on something else, so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop reading the petrol pump.
- Stop the moment you realise. Less petrol in your tank makes a thinner mixture. It doesn't change what to do next, which is still not to fire it up.
Earswick: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with your ignition off as well. Yet at the forecourt, at JET or anywhere else? Ask the attendants to help you roll the vehicle away from the pump. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Earswick page.
One petrol in a diesel task in Earswick costs more than another. Why?
The four scenarios above are four separate tasks, so no single quote for this would be honest. What shifts the cost is mostly which of them you're in. The share counts next, meaning how much of your tank is petrol, followed by the position of the car and whether reaching it is safe for a technician.
Ahead of any quote, not after, we ask three queries: the fuel that was put in, the quantity, and if it has run. That is why. With the replies, you get a straight figure rather than a range.
About Earswick and its setting
Earswick is a small village situated on the River Foss in North Yorkshire, close to the city of York. Earswick has a low elevation of around 19 metres, reflecting its riverside location. Earswick is characterised by its predominantly detached housing stock, with the village lying just 3.5 miles from York and 177.1 miles from London.
Fuel drain cover in Earswick and across North Yorkshire
Our teams answering petrol in diesel call-outs around Earswick, in the YO postcode area, equally work the locations near it, Towthorpe, Haxby and Huntington among them. Our engineers drain where the vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Earswick: still at the pump?
Then, you could not be in a better spot. Leave it switched off, then ring.