How Worried Should You Be? Petrol in a Diesel Car in Fivehead
Far less than you probably are, if it hasn't been started. Everyone around Fivehead begins with "have I wrecked it?", and the honest answer is normally no: petrol left inside that tank of any diesel stays harmless till priming, cranking or driving pulls it into the system. Keep it that way: leave your motor off and phone Petrol in Diesel. What petrol really does to a diesel, how to judge how far it's gone, and how to stop it from happening again: that is the rest of this page.
Your engine and petrol in a diesel: what goes on
Diesel does two jobs on its way through an engine. It ignites, and before it burns it protects. What keeps the surfaces inside your high-pressure pump and your injectors from wearing against each other is your diesel passing through them — they're made to very fine clearances.
Petrol handles the first task poorly and the second not at all. The clattering comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system rests on, and any pump running on such a mix is wearing itself.
Together, those make the shape of the problem plain. The harm is done by circulation, not by contact. Petrol in a tank is a fuel issue. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors beyond it.
Fivehead, petrol in a diesel: four cases, from mild to serious
Fuelled but never started — as good as it gets. That petrol is inside your tank and just the tank, and the task is a drain and a flush where the vehicle sits. This is the one scenario that can only really take place at a forecourt, because anywhere else the vehicle has been driven to get there.
Started for a second, or only the ignition on. With your system primed, your lines and filter already contain petrol that came from the tank. Drain, flush, see to the fuel filter: still normally simple.
Those few miles driven were the pump running on fuel thinned by petrol the whole way. Tank, lines, filter, then fresh fuel run through the entire system: that is this work, and the way your car was driven matters as much as the mileage. Short trips, like the school run to Curry Mallet Church of England Primary School, are one thing. Very different once more: a trip to Wells, under 25 miles away, or any miles on the M5, under 10 miles from Fivehead, where the motor never stopped labouring hard.
Driven till it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. That's your engine telling you its fuel no longer is behaving like diesel. Whether it's the verge on Gange's Hill, a lay-by or a side street, stop where you are and leave it. Permanent damage is very uncommon if a car is pulled over quickly, and the fuel drain and flush that still come first sort it out.
Fivehead drivers and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. A diesel fuel system doesn't accept petrol by percentage in the way that guidance supposes.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through finer parts: that's how a modern diesel moves its fuel, and so the protection counts more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that catches drivers. Diesel in a petrol motor generally means a motor that will not run: the driver stops, and so does the harm. Whilst your pump wears, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Being able to run is not proof of being fine.
Myth: a two-stroke additive lets you to drive home. It is an old workaround, supposed for another issue. None of what petrol weakened gets put back by it — and afterwards, your tank still contains that petrol.
Myth: "Drain your tank yourself and you are sorted." After the engine has been run, some of that petrol is no longer in the tank: it is in the filter and the fuel lines, and it goes straight back through your pump on the next start. Draining petrol into a can at the roadside is also truly hazardous.
How petrol ends up: petrol in a diesel
Nobody does it on purpose, and it is seldom carelessness. A diesel nozzle mostly won't fit a petrol motor, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error easy, and just in one direction.
The moment habit stops matching the vehicle is the moment it takes place. Any vehicle that is new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a well-known forecourt. Rushing for a train outside Taunton and fuelling up en route. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: precisely when it occurs. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Fivehead motorists: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Check the petrol pump's label; the colour is only a hint.
- Many vehicles state the fuel inside the filler flap or on the cap, so check there on your first fill in a motor you don't know.
- One of each in the home? Label your key to your diesel — a bright fob, a sticker — since 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 seems silly and it does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and aftermarket devices are available for the rest. Count it as a safety net, then keep reading the petrol pump.
- As soon as you notice, stop: less petrol in your tank makes a weaker blend. What to do next does not change, though — still don't fire it up.
Fivehead: already put petrol in a diesel?
Then the order of things is brief. Don't switch your ignition on, and do not fire it up. Ask the staff to help you push it away from the pump if you're still on the forecourt, whether that is BP or anywhere else. Next, 0333 366 0103. We'll ask what got in, about how much, and if it has been run.
If it was AdBlue and not petrol, say so. That's a different issue — corrosion and deposits rather than lost protection — and it has its own page for Fivehead.
What makes one Fivehead petrol in a diesel task cost more than the next
There is no honest single price for this, since the four scenarios above are four different tasks. Which of them you're in is mostly what moves the cost. The share counts next, meaning how much of that tank is petrol, followed by the position of the car and whether reaching it is safe for a van.
What was put in, how much, and if it's run — three queries our engineers ask before costing, not after, for exactly that reason. A range becomes a straight figure once those answers are in.
About Fivehead, for a moment
Fivehead is a small village in inland Somerset, situated near the villages of Lower Swell and Upper Fivehead. Fivehead sits at an elevation of around 46 metres, approximately 18 miles from the city of Wells. Fivehead has a population of around 609 people, predominantly living in detached houses. Fivehead is located in the South West region of England, about 126 miles west of London.
Fuel drain cover across Somerset, Fivehead included
Fivehead waits in the TA postcode area, and our teams that answer petrol in diesel jobs there work the places around it as well — Lower Swell, Upper Fivehead and Swell among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and your car does not need to move to us.
In Fivehead and still at the pump?
In that case, you couldn't be in a better spot. Keep the car turned off, then ring.