Petrol in a Diesel Car in Settle: How Worried Should You Be?
Far less than you likely are, provided it hasn't been started. Petrol resting in a diesel tank does nothing to the engine till something draws it through the system — the ignition priming the pump, the starter, or the drive itself. So the fair answer to the first question everyone in Settle asks, "have I ruined it?", is normally no. Petrol in Diesel is who to phone, with your engine kept off, and so it remains that way. Further down, this page sets out what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Inside the engine: what petrol in a diesel really does
On its way through a motor, diesel does two tasks. Before it burns, it protects — then it burns. What stops the surfaces inside your high-pressure pump and the fuel injectors from wearing against each other is the diesel passing through them — they're made to very fine tolerances.
Petrol handles the first job badly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump running on that mixture to wear itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you hear the rattling.
The shape of the trouble is plain when you put those together. Not contact but circulation is what causes the damage. Where the petrol is only inside the tank, it's a fault of fuel, nothing more. Once your pump has been running on that petrol, a mechanical issue has started: whatever is shed by a pump that's wearing is carried onward to your injectors with your fuel.
Four scenarios our technicians see around Settle: how serious is petrol in a diesel?
Fuelled up, never started. The best case there is. At a forecourt, and genuinely only there, the petrol is still limited to your tank — because everywhere else your car was driven to get to it. The task is emptying and rinsing on the spot.
Started for a moment, or just the ignition on. Once primed, your system has drawn petrol from the tank up to the filter and the fuel lines. That is usually still a simple task — a drain, a flush, and the fuel filter seen to.
Your pump has spent a couple of miles on weakened fuel — that's what driving it meant. The work is the tank, your lines, the fuel filter and clean fuel through the entire circuit, and how hard the car was driven counts as much as how far. A school run to Settle Church of England Voluntary Controlled Primary School is one matter. Very different once more: a trip to Lancaster, under 25 miles away, or some miles on the M65, under 25 miles from Settle, where the engine kept working hard.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven until it complained. The engine is telling you the fuel is no longer behaving like diesel. Leave it where it stops: a lay-by, a side street, the verge on Station Road. Permanent damage is very rare when a car is pulled over early, and the drain and flush that still go first sort it out.
What Settle drivers get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you're left with a fuller tank, still the same mix. That advice presumes a diesel fuel system handles petrol by percentage. It doesn't.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." Finer parts and higher pressure are the way a current diesel runs its fuel, and that makes the protection count more, not less.
One myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it generally won't run, and so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it usually starts, idles and pulls away as if nothing happened — all the while its pump wears. Being able to run is not proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate fault. What petrol has weakened remains diluted, and the petrol remains inside the tank anyway.
Myth: "Drain your tank yourself and you are sorted." After the motor has been run, some of that petrol is no longer inside your tank: it is in the fuel filter and your lines, and it goes straight back through the pump at the next start. Also, a can of petrol filled at the roadside is genuinely hazardous.
Petrol in a diesel: how does it take place?
A careless moment is seldom the cause, and nobody means to do it. One way only, because of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol motor. That's how the forecourt makes it straightforward.
When habit and your car stop matching, it takes place. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. A train to catch, and a hurried fill on the way to the nearest station. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is exactly the moment it takes place. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up around Settle: preventing petrol in a diesel
- The label is what counts, and so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, but not on every forecourt.
- Inspect the filler flap. Plenty of cars state the fuel inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- One of each in the household? Mark the key to your diesel — a coloured fob, a sticker — because intending to remember is not enough.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It sounds silly and it does the trick.
- Put your phone away. This is an easy mistake to make whilst you are thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built 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 weaker mixture, and so stop as soon as you realise — though remembering that the next step is unchanged. It's still not to fire it up.
Settle: already put petrol in a diesel?
Then, there is just a short order of things. Don't start the car, and don't turn your ignition on. The staff on the forecourt — whether at Asda Express itself or wherever you filled up — will normally help roll it away from the petrol pump if you ask. What went in, roughly how much, and whether it has run: tell us that when you phone 0333 366 0103.
Corrosion and deposits are the issue with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Settle page.
Settle petrol in a diesel jobs: why one costs more than another
A fair single price doesn't exist here: four scenarios, four separate tasks. What shifts your cost is chiefly which of them you are in. Where the vehicle is matters too, and whether our van can safely reach it, after the ratio of petrol to what that tank takes.
What was put in, how much, and if it has run — three queries our technicians ask before pricing, not after, for precisely that reason. The replies change a range into a straight figure.
About Settle and where it is
Settle is a town situated in the Ribble Valley in North Yorkshire, with a riverside setting and an elevation of 159 metres. Settle has a mix of housing types, but is predominantly characterised by terraced properties. Settle is located near several smaller communities, including Upper Settle, Giggleswick, and Langcliffe, and is approximately 21 miles from Lancaster. Settle has a population of around 3785 people and is about 198 miles from London.
Across North Yorkshire and in Settle: fuel drain cover
Our teams answering petrol in diesel call-outs in Settle, in the BD postcode area, also work the spots around it, Upper Settle, Giggleswick and Langcliffe included. Our engineers drain wherever the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Settle: still at the petrol pump?
Nothing beats it: that is where you are. Keep it off. Phone.