Wood Royd: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, worry less than you probably are. Petrol sitting in a diesel tank does nothing to your motor until something draws it through the fuel system — your ignition priming the pump, your starter, or driving itself. So the truthful answer to the first question anyone around Wood Royd asks, "have I wrecked it?", is normally no. To leave it like that, call Petrol in Diesel and leave your motor alone. The rest of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
Inside the engine: what petrol in a diesel does
On its way through a motor, diesel does two tasks. Before it ignites, it lubricates — and then it combusts. The high-pressure pump and the injectors are built to extremely fine tolerances, and the diesel passing through them is what keeps those surfaces from wearing against one another.
The second task petrol doesn't do at all, and the first it does badly. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system rests on, and any pump working on such a blend is wearing itself.
The shape of the issue is plain when you put those together. Contact does not do the harm — movement does. Where that petrol is only in that tank, it is a fault of fuel, nothing more. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to your injectors downstream.
Wood Royd, petrol in a diesel: four situations, from mild to significant
The best case there can be: filled up, never started. Just that tank has petrol in it, so the task is clearing your tank and rinsing your system where the car stands. This situation can only really happen at a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a moment. Your system has been bled, so petrol has left that tank and got to the filter and the lines. Usually little more than draining, flushing and sorting the fuel filter, and so still straightforward.
A few miles driven, and your pump has spent every one of them labouring on thinned fuel. Miles is only half of it; how hard it was driven matters equally. Either way this work includes the tank, the lines, the fuel filter and clean fuel through the entire circuit. On the school run to Royd Nursery and Infant School, the mileage is short. A run as far as Sheffield, under 10 miles away, is a very different job. So is any miles on the M1, under 5 miles from Wood Royd, where your engine has been labouring hard the whole time.
Knocking, an uneven idle, smoke, a throttle gone soft: driven till it complained. The fuel is not acting like diesel any more, and your engine is saying so. Leave it where it has stopped: a lay-by, a side street, the verge on Armitage Road. What goes first is still the fuel drain and flush-through, and that takes care of it, with permanent damage very uncommon if a vehicle is pulled over soon.
Petrol in a diesel myths Wood Royd people hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. That guidance presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
"Current diesels can handle a little petrol" — a myth, and nearer the opposite. A current diesel runs its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that catches people. Feed diesel to a petrol motor and it normally will not run, so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it normally fires up, idles and drives away as if nothing happened — all while its pump is wearing. A running engine does not mean fine.
An outdated fix for a separate problem is behind this one. Myth: "Add some two-stroke oil and drive the car home." The petrol is still inside that tank after that, and what it has thinned isn't put back.
If your engine has been run, part of that petrol is in the filter and your lines, not the tank — and your next start pulls it straight back through your pump. So the myth "drain that tank yourself and you're sorted" doesn't stand up. And, a can of petrol drained at the roadside is truly hazardous.
Why petrol in a diesel takes place so easily
It is seldom carelessness, and no one does it on purpose. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol car at all. The forecourt makes it simple, and the error runs one way.
The moment routine stops matching your car is the moment it happens. A motor that is new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps suddenly in a different order. Filling up in a hurry on the way to Penistone, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. With rain, a call arriving, or children to deal with, your hand simply does what it always has.
How to avoid petrol in a diesel on your next fill-up in Wood Royd
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is just a hint.
- The first fill in a strange car is the time to check the filler flap — on it, or on the cap, many motors state which fuel to use.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key if a home has one of each. So label it.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds daft. It works.
- Whilst you're thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices are available for motors without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol inside the tank means a weaker mixture. It doesn't change what to do next, which is still not to crank it.
Petrol already in a diesel in Wood Royd? Start here
The order of things is short, then. Leave it unstarted, with your ignition switched off as well. Ask the attendants to help you roll it clear of the pump if you're still on the forecourt, whether that is Murco or anywhere else. Then ring 0333 366 0103 and tell us what went in, about how much, and if it's run.
If it was AdBlue rather than petrol, say so. That is a different issue — corrosion and deposits rather than lost protection — and it has its own page for Wood Royd.
Wood Royd petrol in a diesel jobs: why one costs more than another
Four separate tasks lie behind the four situations above — which is why there's no fair single price. The scenario itself does most of the work of moving your cost. Where your car is matters too, and whether a van can safely reach it, after the ratio of petrol to what the tank holds.
Three questions come first, before quoting, rather than after — what was put in, how much, has it run — and this is the reason. The replies change a range into a straight figure.
About Wood Royd itself
Wood Royd is a suburban area situated near the River Don in South Yorkshire, with an elevation of around 204 metres. Wood Royd lies approximately 7.9 miles from Sheffield and is part of the larger urban area surrounding the city. Wood Royd has a mix of housing types, but semi-detached homes are the most common, and its population is around 5388 residents. Wood Royd is close to nearby places such as Old Haywoods, Carr Head, and Royd.
Across South Yorkshire and in Wood Royd: fuel drain cover
Petrol in diesel jobs around Wood Royd — part of the S postcode area — go to vans that likewise cover the locations about it, Old Haywoods, Carr Head and Royd among them. The vehicle doesn't need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Wood Royd: still at the pump?
No position is better: that is where you now are. Phone, and leave it turned off.