Dingleton: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — as long as no one has started the car. "Have I ruined it?" is the first thing everyone around Dingleton asks, and the truthful answer is normally no, because petrol left in a diesel tank harms nothing till it is dragged through your fuel system — by ignition priming, by your starter, or by being driven. Keep it like that: leave your motor off then call Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's gone, and how to keep it from happening a second time: that's the remainder of this page.
The engine and petrol in a diesel: what goes on
Two tasks fall to diesel on its route through a motor. Before it combusts, it lubricates — then it combusts. Extremely fine gaps are built into your injectors and your high-pressure pump, and only the diesel flowing through stops their surfaces grinding together.
Of those two tasks, petrol handles the first badly and the second not at all. It's thinner than diesel and removes the protection your fuel system depends on, so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the problem is clear when you put those together. Not contact but circulation is what does the damage. Where the petrol is only inside the tank, it is an issue of fuel, nothing more. Whatever a worn pump sheds goes on, carried by your fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical issue starts.
How serious is petrol in a diesel? Four scenarios we see around Dingleton
The best case there can be: filled up, not once started. Just that tank has petrol in it, so the job is emptying your tank and flushing your system where the vehicle stands. This situation can only truly happen on a forecourt: anywhere else, the car got there by being driven.
A brief spell of running, or just the ignition on. Petrol has left the tank and reached your filter and the lines, because the fuel system has been bled. Usually little more than clearing, flushing and sorting your filter, so still simple.
A couple of miles driven, and the pump has spent each of them running on weakened fuel. Mileage is only half of that; how hard it was driven counts just as much. Either way the work includes your tank, the lines, the filter and clean fuel through the entire circuit. A school run to the local primary school is one matter. Any miles on the M8, under 50 miles from Dingleton, means your engine has worked hard throughout, and a run to Edinburgh, under 50 miles away, is a very different job as well.
Driven till it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. That's your motor telling you its fuel has stopped behaving like diesel. Stop where you are — on the verge on Chiefswood Road, at the kerb, down a side road — and don't move it. What comes first is still the fuel drain and flush, and that deals with it, with long-term damage very uncommon when a vehicle is pulled over early.
Myths Dingleton people hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all you get, because topping up removes nothing. Percentage isn't how a diesel fuel system copes with petrol, whatever that guidance assumes.
Myth: a newer diesel copes with a bit of petrol. Rather, the reverse. More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication count more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. A petrol motor fed diesel normally will not run, so the driver stops and the harm stops with them. Feed petrol to a diesel and it normally starts, ticks over and drives away like nothing happened — all the while its pump is wearing. Fine and running aren't the same at all.
Myth: a two-stroke additive lets you to drive home. It is an old fix, supposed for another problem. It does not put back what petrol has thinned, and the petrol is still inside that tank afterwards.
Myth: "Drain that tank yourself and you're sorted." After the motor has been run, some of that petrol is no longer inside the tank: it is in the fuel filter and the fuel lines, and it goes right back through your pump at the next start. It is also truly hazardous to drain petrol into a can at the roadside.
How it happens: petrol in a diesel
No one does it on purpose, and it is rarely carelessness. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol car. That's how the forecourt makes it straightforward.
It takes place when routine and the vehicle stop matching. Hire cars, courtesy cars, and cars that are new to you. Two motors on one drive, one petrol, one diesel. A well-known forecourt with the pumps in a different order. A hurried fill on the way to Tweedbank with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: exactly when it happens. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up around Dingleton
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Read the petrol pump's label; the colour is just a hint.
- The first fill in a new vehicle is the time to check the filler flap — inside it, or on the cap, plenty of motors state the fuel to use.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a home has one of each. So label it.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Silly, yes, yet it works.
- Thinking about something else is when this becomes an easy mistake to make, and so put your phone away then keep your mind on the petrol pump.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- The moment you realise, stop: less petrol in that tank means a weaker mix. What to do next does not change, though — still don't crank it.
Already put petrol in a diesel around Dingleton?
Short and simple, then, is the order of things. Starting it is out, and so is switching on your ignition. If you're still at the forecourt — BP or anywhere else — ask the attendants to help you push the vehicle clear of the pump. Call 0333 366 0103 next, with three answers — your fuel, the approximate volume, and if it's run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and see its own Dingleton page.
What makes one Dingleton petrol in a diesel task cost more than the next
The four situations above are four different tasks, so no single quote for this would be fair. Which of them you are in is mostly what moves the cost. The proportion matters next, meaning how much of the tank is petrol, and then the position of your car and whether getting to it is safe for a van.
Three queries come first, before any quote, rather than after — what was put in, how much, has it run — and that is the reason. Those replies are what turn a range into one firm number.
About Dingleton and where it is
Dingleton is a suburban area situated on the riverside in the Scottish Borders, with a population of around 1152 people. Dingleton is characterized by its semi-detached housing and is located near the towns of Melrose and Galashiels. Dingleton sits at an elevation of 153 metres, close to the nearby villages of Highcross and Darnick. Dingleton is approximately 30 miles from Edinburgh, Scotland's capital city.
Dingleton and Scottish Borders: where our fuel drain cover runs
The vans answering petrol in diesel jobs around Dingleton, in the TD postcode area, also work the locations near it, Melrose, Highcross and Darnick included. The car does not 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.
Dingleton: still at the pump?
Then, you couldn't be in a better spot. Switched off it stays; then ring.