Should You Worry? Petrol in a Diesel Car in Park Wood
Probably less than you are now — as long as nobody has started it. Petrol resting in a diesel tank does nothing to the motor until something draws it through your fuel system — your ignition priming the pump, your starter, or driving on its own. So the honest answer to the first question everyone in Park Wood asks, "have I ruined it?", is usually no. To keep it that way, ring Petrol in Diesel and leave your motor switched off. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening again: that's the remainder of this page.
Inside the motor: what petrol in a diesel does
Two jobs fall to diesel on its journey round a motor. It protects to begin with, and only then does it burn. The high-pressure fuel pump and the fuel injectors are designed to extremely fine tolerances, and your diesel passing through them is what keeps those surfaces from grinding against one another.
Of those two tasks, petrol manages the first badly and the second not at all. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on that mixture to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the rattling.
Taken together, they show what shape the problem has. Not contact but circulation is what causes the harm. Where the petrol is only inside that tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds goes on, borne by the fuel, into your injectors downstream, which is why a pump that has worked on the petrol is where a mechanical problem begins.
Four scenarios our engineers see around Park Wood: how serious is petrol in a diesel?
Filled up, and never started: no case is better. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in the tank alone, it is cleared and rinsed on the spot, and nothing more is needed.
Your ignition turned on, or a short start. Petrol has come out of the tank and got to your filter and the fuel lines, because your system has been bled. Usually little more than emptying, flushing and sorting the filter, and so still easy.
A few miles driven, and your pump has spent each of them labouring on diluted fuel. How hard the vehicle was driven counts as much as how far, and this work covers that tank, the lines, your filter and clean fuel through the entire circuit. Short trips, like the school run to St Augustine of Canterbury Catholic Primary School, are one thing. Any miles on the M2, under a mile from Park Wood, means the motor working hard throughout, and a run to Southend-on-Sea, under 15 miles away, is a very different task too.
Driven on till it complained — knocking, smoke, a lumpy idle, a soft throttle. What you are hearing is the engine signalling fuel that no longer runs like diesel. Stop wherever you are — the verge on Deanwood Drive, a lay-by, a side street — and leave it where it is. Long-term damage is very unusual when a car is stopped quickly, and the drain and flush that still go first deal with it.
Petrol in a diesel myths Park Wood drivers hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mix. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." A modern diesel runs its fuel through more precise components at higher pressure, which makes the protection matter more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it generally won't run, and so the motorist stops — and the damage stops with them. While your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate problem. None of what petrol diluted is put back by it — and afterwards, that tank still contains that petrol.
Once the motor has run, part of the petrol is in your filter and the lines, not that tank — and your next start pulls it right back through your pump. So the myth "drain that tank yourself and you are sorted" doesn't stand up. And, a can of petrol filled at the roadside is truly risky.
Petrol in a diesel: how does it occur?
No one does it on purpose, and it's rarely carelessness. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol car at all. So the slip runs one way.
Habit and the car falling out of step is when it takes place. A new vehicle, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. Your normal forecourt, its pumps now in a different order. Racing for a train outside Rainham (Kent) and filling up en route. Exactly the moment it takes place: after years of driving petrol, someone fills a diesel Renault Megane for the first time. The hand repeats what it has always done when you add rain, a phone call or a back seat full of children.
Preventing petrol in a diesel next time you fill up in Park Wood
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is only 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 cars state which fuel they take.
- One of each in the house? Label your key to your diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- It sounds silly and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Tuck your phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- Stop the moment you notice. Less petrol inside that tank means a thinner mixture. It doesn't change what to do next, which is still not to crank it.
Park Wood: already put petrol in a diesel?
The order of things is short, then. Do not switch your ignition on, and don't crank it. The staff at the forecourt — whether at BP itself or wherever you filled up — will normally help push it clear of the petrol pump if you ask. Phone 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and if it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different problem — Park Wood has a page just for it.
One petrol in a diesel job around Park Wood costs more than another. Why?
Four separate jobs sit behind the four situations above — which is why there is no honest single price. Mostly, the cost moves with which situation you're in. Next it's the ratio — how much petrol went in against how much that tank takes — and after that where the car is and whether a technician can get to it safely.
Three questions come first, before any quote, instead of after — what was put in, how much, has it run — and this is the reason. Given those replies, you get a straight figure rather than a range.
About Park Wood
Park Wood is a suburban area in Kent, situated inland at an elevation of 103 metres, and forms part of the wider residential landscape around Southend-on-Sea. Park Wood is characterized by its predominance of terraced housing and is located near other local places such as Farthing Corner and Wigmore. Park Wood sits within the South East region, approximately 33 miles from London, and is a relatively small community with a population of around 7107 residents.
Park Wood and Kent: where our fuel drain cover runs
The teams answering petrol in diesel calls in Park Wood, in the ME postcode area, also work the places around it, Farthing Corner, Wigmore and Meresborough among them. Our technicians drain where the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the petrol pump in Park Wood?
No position is better: that is where you are. Leave it switched off, then ring.