Stoney Middleton: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less anxious than you likely are. Petrol resting in a diesel tank does nothing to your engine until something draws it through the system — your ignition priming your pump, your starter, or driving itself. So the honest answer to the first query everyone in Stoney Middleton asks, "have I ruined it?", is usually no. Keep it that way: leave your engine off and ring Petrol in Diesel. Further down, this page sets out what petrol actually does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
What petrol in a diesel does to the engine
Two tasks fall to diesel on its route round a motor. Before it ignites, it protects — and then it ignites. Very fine gaps are built into the injectors and your high-pressure pump, and only the diesel running through keeps those surfaces from grinding together.
The second job petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump on that mixture to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the clattering.
Seen together, they make clear what shape the trouble has. The damage is done by movement, not by contact. Any tank with petrol in it is a fuel fault. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
Four situations our technicians see around Stoney Middleton: how serious is petrol in a diesel?
Fuelled up, never started. The best case there is. Only that tank has petrol in it, and so the task is emptying your tank and flushing the fuel system where your car stands. This situation can only really take place at a forecourt: anywhere else, your car got there by being driven.
Ignition on, or started for a second. Petrol has come out of your tank and got to the filter and your lines, since the fuel system has been bled. Normally nothing more than emptying, rinsing and sorting the fuel filter, and so still straightforward.
Some miles driven, and your pump has spent each of them labouring on thinned fuel. How hard the car was driven matters as much as how far, and the work covers your tank, the lines, your filter and fresh fuel through the whole system. Short trips, like the school run to Stoney Middleton CofE (C) Primary School, are one thing. Very different once more: a trip to Sheffield, under 15 miles away, or some distance on the M1, under 15 miles from Stoney Middleton, where the engine never stopped labouring hard.
Driven until it complained. Clattering, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is the motor signalling fuel that no longer runs like diesel. Whether it's the verge on Denman Crescent, a lay-by or a side street, stop there and leave it. What goes first is still the fuel drain and flush-through, and that takes care of it, with long-term damage very uncommon if a car is stopped quickly.
What Stoney Middleton drivers get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — your tank just carries more of the same blend. That advice presumes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through more precise parts: that's how a newer diesel handles its fuel, and so the protection matters more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more people than any other. The motorist of a petrol engine fed diesel normally stops, since it will not run, and the harm stops there. While your pump wears, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Running does not mean fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an outdated fix for a distinct issue. That petrol is still in the tank afterwards, and whatever it has diluted isn't put back.
If the engine has run, part of that petrol is in the filter and your lines, not your tank — and your next start sends it straight back through the pump. So the myth "drain the tank yourself and you are sorted" does not hold. Also, a can of petrol drained by the roadside is genuinely risky.
How does petrol in a diesel take place?
Nobody does it on purpose, and it's seldom carelessness. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
The moment routine stops matching the car is the moment it occurs. Hire cars, courtesy cars, and vehicles that are new to you. A household with one petrol and one diesel on the driveway. A well-known forecourt with the pumps in a different order. Racing for a train outside Grindleford and fuelling up en route. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Add a back seat full of children, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up in Stoney Middleton
- A green handle for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- Inspect your filler flap. Plenty of vehicles state the fuel type inside the flap or on the cap. Look at it on your first fill in a vehicle you don't know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a house with one of each.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It sounds daft. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices exist for motors without one. They are a backstop, not a reason to stop reading the petrol pump.
- As soon as you notice, stop: less petrol inside your tank means a thinner blend. What to do next does not change, though — still do not crank it.
Stoney Middleton: already put petrol in a diesel?
Short and simple, then, is the order of things. Do not crank it, and don't switch the ignition on. The attendants at the forecourt — whether at BP itself or wherever you filled up — will normally help roll it clear of the petrol pump if you ask. What got in, roughly how much, and whether it has run: tell us that when you call 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a different problem, with its own page for Stoney Middleton, since AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel task in Stoney Middleton costs more than another. Why?
The four situations above are four separate tasks, so no single quote for this would be honest. Which of them you're in is chiefly what shifts your cost. Where the vehicle is matters too, and whether a technician can safely reach it, after the proportion of petrol to what your tank takes.
What got in, how much, and if it has run — three questions we ask before costing, not after, for precisely that reason. A range turns into a straight figure once the replies are in.
About Stoney Middleton
Stoney Middleton is a village in Derbyshire, situated on the banks of the River Derwent at an elevation of 159 metres. Stoney Middleton has a mix of housing types, with semi-detached homes being the most prevalent, and is located near other local places such as Calver Sough and Eyam. Stoney Middleton is close to the city of Sheffield, which is approximately 10.7 miles away, and is about 138.1 miles from London.
Fuel drain cover around Stoney Middleton and across Derbyshire
Petrol in diesel call-outs in Stoney Middleton — part of the S postcode area — go to vans that likewise cover the locations round it, Calver Sough, Calver Low and Eyam among them. The vehicle does not need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Stoney Middleton: still at the pump?
In that case, you could not be in a better place. Switched off it remains; then phone.