How Worried Should You Be? Petrol in a Diesel Car in Swan Village
Unstarted? Then less anxious than you likely feel. "Have I wrecked it?" is the first question everyone around Swan Village asks, and the truthful answer is normally no, because petrol left in a diesel tank harms nothing until it's drawn through the system — by ignition priming, by your starter, or by being driven. Keep it like that: leave your engine off and call Petrol in Diesel. The remainder of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Inside the motor: what petrol in a diesel really does
Diesel has two tasks on its way through a motor. It combusts, and before it burns it protects. Extremely fine gaps go into the injectors and your high-pressure pump, and just your diesel flowing through stops their surfaces grinding together.
The second job petrol does not do at all, and the first it does badly. The knocking comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication the fuel system depends on, and any pump running on that blend is wearing itself.
The shape of the issue is clear once you put those together. It is movement that causes the harm, not contact. A tank with petrol in it is a fuel issue. Once the pump has been working on that petrol, a mechanical fault has started: anything shed by a pump that's wearing travels downstream to your injectors with your fuel.
Swan Village, petrol in a diesel: four cases, from mild to significant
The best case there is: filled up, not once started. At a forecourt, and really only there, the petrol is still confined to the tank — because everywhere else the vehicle was driven to get to it. The task is emptying and purging on the spot.
The ignition switched on, or a short start. With the system primed, the fuel lines and filter already contain petrol that came from that tank. That's usually still an easy task — a drain, a flush, and your filter dealt with.
Driven a few miles. Now the pump has spent those miles labouring on weakened fuel. Tank, lines, filter, then fresh fuel put through the entire circuit: that's the work, and the way the car was driven matters as much as the miles. The school run to Bramford Primary School is one thing. Getting as far as Wolverhampton, under 5 miles away, makes a very different job — as does any miles on the M6, under 5 miles from Swan Village, with the motor labouring hard the whole time.
Driven till it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer behaving like diesel. Pull up where you are — on the verge on Rosalind Avenue, at the kerb, down a side road — and do not move it again. The drain and flush-through still come first, and they sort it out: if a vehicle is pulled over soon, lasting damage is very unusual.
Swan Village motorists and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A fuller tank of the same mixture is all you get, because topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that advice assumes.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that's how a modern diesel handles its fuel, and so the protection counts more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." Diesel in a petrol motor normally leaves a motor that will not run: the motorist stops, and so does the damage. While your pump grinds, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Fine and running aren't the same at all.
Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, supposed for another fault. What petrol has diluted stays diluted, and the petrol stays in your tank anyway.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in your filter and lines, ready to go straight back through the pump at your next start. Emptying petrol into a can by the roadside is also truly dangerous.
Why petrol in a diesel occurs at all
No one does it on purpose, and it's rarely carelessness. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol vehicle at all. So the error runs one way.
Habit and your car getting out of step is when it takes place. Any motor that is new to you — a hire car, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the driveway. A familiar forecourt with the pumps in a different order. Filling up in a rush on the way to Coseley, with a train to catch. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Tiguan for the first time. With rain, a call arriving, or children to deal with, your hand just does what it always has.
How to avoid petrol in a diesel at your next fill-up in Swan Village
- Check the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on each forecourt. The label is what counts.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of motors print the fuel type there.
- One of each in the home? Mark the key to your diesel — a bright fob, a sticker — since intending to remember isn't enough.
- Before the nozzle comes off the pump the first time you fill a hired or new car, say "diesel" aloud. Daft, yes, but it does the trick.
- Tuck your phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices exist for vehicles without one, and some diesels come with a filler that won't take a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol in the tank makes a thinner blend. What to do next does not change, though — still don't crank it.
Swan Village: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off too. The attendants at the forecourt — whether at Shell itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Corrosion and deposits form the issue with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own Swan Village page.
What makes one Swan Village petrol in a diesel job cost more than the next
The four situations above are four different jobs, so no single price for this would be fair. Which of them you're in is mostly what shifts the cost. The share counts next, meaning how much of your tank is petrol, and then the position of the vehicle and whether getting to it is safe for a technician.
Three queries come first, before any quote, instead of after — what got in, how much, has it run — and that is the reason. The replies turn a range into a straight figure.
About Swan Village, for a moment
Swan Village is a suburban area located near Wolverhampton in the West Midlands, sitting at an elevation of around 163 metres. Swan Village is characterized by its predominantly semi-detached housing stock, reflecting the typical residential development of the region. Swan Village is situated close to other nearby places such as Bramford and Parkes Hall, and is about 3.8 miles from Wolverhampton city centre.
Swan Village and West Midlands: where our fuel drain cover reaches
Swan Village sits in the DY postcode area, and our vans that answer petrol in diesel jobs there work the spots around it as well — Bramford, Parkes Hall and West Coseley among them. We drain where the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the pump around Swan Village, still?
In that case, you couldn't be in a better position. Keep it off. Ring.