Should You Worry? Petrol in a Diesel Car in Ribchester
Far less than you likely are, if it hasn't been started. Petrol resting in a diesel tank does nothing to your engine until something pulls it through the system — the ignition priming the pump, your starter, or the drive itself. So the fair answer to the first query everyone in Ribchester asks, "have I wrecked it?", is normally no. Petrol in Diesel is who to call, with your engine kept off, and so it remains that way. The rest of this page explains what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Inside the motor: what petrol in a diesel really does
Passing through an engine, diesel does two things at once. It lubricates to begin with, and after that does it burn. What keeps the surfaces inside your high-pressure pump and the fuel injectors from wearing against one another is the diesel flowing through them — they're made to extremely fine gaps.
The second job petrol does not do at all, and the first it does badly. The rattling comes from petrol being designed 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 out the protection the system hinges on, and any pump working on that blend is wearing itself.
Together, those leave the shape of the trouble plain. It is circulation that causes the damage, not contact. Where the petrol is only in your tank, it's a fault of fuel, nothing more. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with your fuel to the injectors beyond it.
Four scenarios our engineers see in Ribchester: how bad is petrol in a diesel?
Fuelled but not once started — as good as it gets. The petrol is in the tank and only the tank, and the task is a drain and a flush where your car sits. This is the one scenario that can only truly occur on a forecourt, as anywhere else the vehicle has been driven to get there.
A moment's running, or merely your ignition on. Once primed, the fuel system has drawn petrol out of your tank as far as the fuel filter and the fuel lines. Usually little more than clearing, cleaning and sorting the filter, so still simple.
Your pump now spent a couple of miles on thinned fuel — that's what driving the vehicle does. How hard the vehicle was driven matters as much as how far, and the work takes in that tank, the fuel lines, your filter and fresh fuel through the entire circuit. Short trips, like the school run to Ribchester St Wilfrid's Church of England Voluntary Aided Primary School, are one matter. Any mileage on the Preston Bypass, under 10 miles from Ribchester, means your engine working hard throughout, and a run to Preston, under 10 miles away, is a very different job too.
Driven on until it protested — rattling, smoke, a ragged idle, a soft throttle. The motor is telling you the fuel is no longer acting like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Ribblesdale Road. What goes first is still the fuel drain and flush-through, and that sorts it out, with permanent damage very uncommon when a vehicle is pulled over quickly.
Petrol in a diesel stories Ribchester people hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A bigger tank of the same mix is all you get, since topping up takes out nothing. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance supposes.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. A newer diesel runs its fuel through more precise components at higher pressure, which makes the lubrication matter more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel usually stops, since it will not run, and the damage stops there. Feed petrol to a diesel and it usually fires up, ticks over and pulls away like nothing has happened — all while its pump wears. Being able to run is not 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 distinct fault. The petrol is still inside the tank after that, and what it has weakened isn't put back.
Myth: "Drain that tank yourself and you are sorted." Once the motor has been run, some of that petrol is no longer inside your tank: it is in the fuel filter and the fuel lines, and it goes straight back through your pump at your next start. It's also genuinely hazardous to drain petrol into a can by the roadside.
How does petrol in a diesel occur?
Carelessness is seldom 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 slides into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol vehicle at all. So the mistake runs one way.
Routine and the car getting out of step is when it happens. Any vehicle that is new to you — a hire car, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. Filling up in a hurry en route to Ramsgreave & Wilpshire, with a train to catch. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is exactly the moment it takes place. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Ribchester drivers: how to prevent petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the petrol pump's label; the colour is only a clue.
- In a car you don't know, look inside the flap over the filler or at the cap before the first fill: many vehicles print the fuel type there.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, for a home with one of each.
- It seems daft and it works: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes 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 vehicles without one. They are a backstop, not a reason to stop reading the petrol pump.
- Less petrol makes a thinner mix, so stop as soon as you realise — though remembering that your next step is unchanged. It's still not to crank it.
Petrol already in a diesel in Ribchester? Start here
Short and simple, then, is the order of things. Starting it is out, and so is turning on the ignition. Ask the attendants to help you roll it away from the pump if you are still on the forecourt, whether that's SPAR Pennine Service Station or anywhere else. Ring 0333 366 0103 next, with three answers — your fuel, the approximate amount, and if it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate problem — Ribchester has a page just for it.
Ribchester petrol in a diesel jobs: why one costs more than another
The four situations above are four separate tasks, so no single quote for this would be honest. Which of them you are in is chiefly what shifts the cost. The ratio matters next, meaning how much of the tank is petrol, followed by the location of the vehicle and whether reaching it is safe for our van.
That's why our engineers ask three queries before pricing instead of after: what went in, how much, and if it's run. Those replies are what change a range into one firm number.
About Ribchester and where it is
Ribchester is a village in Lancashire, situated on the banks of the River Ribble at an elevation of around 30 metres. Ribchester lies approximately 7.7 miles north-west of Preston and 188.5 miles north of London, with nearby settlements including Stydd, Little Town, and Osbaldeston Green. Ribchester has a population of around 851 people, predominantly living in terraced housing.
Fuel drain cover across Lancashire, Ribchester included
Ribchester waits in the PR postcode area, and the teams that answer petrol in diesel jobs there work the locations around it as well — Stydd, Little Town and Osbaldeston Green among them. No need to move the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots where we work.
At the pump around Ribchester, right now?
No position is better: that is where you now are. Switched off it stays; then phone.