Should You Worry? Petrol in a Diesel Car in Gowkshill
Likely less than you already are — as long as no one has started the car. Until the ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank just waits there and does nothing. Which makes the truthful reply to that first Gowkshill query — "have I wrecked it?" — usually no. Petrol in Diesel is who to ring, with your engine left off, and so it stays that way. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and ways to make sure you never repeat it.
Inside the motor: what petrol in a diesel does
Passing through an engine, diesel is doing two jobs at the same time. Lubricating comes before burning; it does both. Extremely fine tolerances are built into the injectors and the high-pressure pump, and just your diesel running through stops their surfaces grinding together.
The second task 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 precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the fuel system rests on, and any pump running on that mix is wearing itself.
The shape of the problem is plain when you put those together. Not contact but circulation is what causes the damage. A tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, carried by the fuel, into your injectors downstream, which is why a pump that has worked on that petrol is where a mechanical issue begins.
Gowkshill, petrol in a diesel: four cases, from mild to serious
Filled but never started — the best it gets. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With the petrol held inside the tank alone, it's drained and rinsed right where it stands, and nothing more is needed.
The ignition switched on, or a short start. Once primed, the fuel system has pulled petrol out of that tank up to the fuel filter and the lines. Normally little more than clearing, rinsing and seeing to the filter, and so still simple.
Those few miles driven were your pump working on fuel thinned by petrol the whole way. Tank, lines, filter, then fresh fuel run through the whole circuit: that's the work, and the way the vehicle was driven counts as much as the mileage. Driving the kids to the local primary school is one sort of trip. Getting as far as Edinburgh, under 10 miles away, makes a very different job — as does any miles on the M8, under 15 miles from Gowkshill, with the engine running hard the whole time.
Driven on until it protested — rattling, smoke, a lumpy idle, a soft throttle. That is your engine telling you its fuel no longer is acting like diesel. Pull up where you are — on the verge on Stobhill Road, at the kerb, down a side road — and don't move it. What goes first is still the fuel drain and flush-through, and that deals with it, with lasting damage very rare when a car is pulled over early.
What Gowkshill motorists get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." A bigger tank of the same mixture is all it gives, since topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." A modern diesel sends its fuel through smaller parts at higher pressure, which makes the protection matter more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally means a motor that will not run: the motorist stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive it home." It is an old workaround for a distinct issue. None of what petrol diluted is put back by it — and later, your tank still holds that petrol.
Myth: "Drain the tank yourself and you're sorted." Once your engine has run, some of that petrol is no longer inside that tank: it is in the fuel filter and your lines, and it goes straight back through the pump on your next start. Besides, petrol drained into a can by the road is genuinely hazardous.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. A diesel nozzle generally will not fit a petrol car, but the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake straightforward, and just in that direction.
The moment habit stops matching the car is the moment it occurs. A new vehicle, a hire car or a courtesy car. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a familiar forecourt. A rushed fill on the way to Newtongrange with a train to catch. 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.
Gowkshill motorists: how to avoid petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Trust the label on the pump, not the colour.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: many cars print the fuel there.
- Mark the key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car needs its first tank. It seems daft. It does the trick.
- Mistakes like this are easy to make while 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 built to block a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a backstop, then keep checking the pump.
- Spotting it mid-fill? Stop at once. A weaker mixture results from less petrol inside your tank, yet your next stage stays the same: don't start it.
Petrol already in a diesel around Gowkshill? Start here
Short and simple, then, is the order of things. Never crank it, and don't switch your ignition on. Ask the attendants to help you roll it away from the petrol pump if you are still on the forecourt, whether that is Shell or somewhere else. Call 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and if it has run.
Say so if it was AdBlue rather than petrol: it is a separate problem, with its own page for Gowkshill, because AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Gowkshill petrol in a diesel task cost more than the next
The four scenarios above are four different jobs, so no single quote for this would be honest. Which of them you're in is chiefly what shifts the cost. Where your car is counts too, and whether a van can safely get to it, after the share of petrol to what that tank takes.
That's why we ask three queries before quoting 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 Gowkshill, for a moment
Gowkshill is a small village in Midlothian, situated inland at an elevation of 145 metres, approximately 8 miles from Edinburgh. Gowkshill lies near several other communities, including Monkswood, Arniston, and Newtongrange. Gowkshill has a population of around 581 people, predominantly residing in flats. Gowkshill is located about 323 miles north of London, in the central lowlands of Scotland.
Across Midlothian and around Gowkshill: fuel drain cover
Gowkshill sits in the EH postcode area, and our vans that answer petrol in diesel call-outs there work the spots around it as well — Monkswood, Arniston and Newtongrange among them. The car doesn't need to move to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Gowkshill: still at the pump?
Then you're in the best place there is. Phone, and keep it switched off.