Broseley: 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 pulls it through your fuel system — your ignition priming the pump, your starter, or driving itself. So the fair answer to the first question anyone around Broseley asks, "have I wrecked it?", is generally no. Petrol in Diesel is who to ring, with the motor left off, and so it remains that way. The remainder of this page sets out what petrol really 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.
What petrol in a diesel does to the engine
Diesel does two tasks on its way through an engine. Lubricating comes before burning; it does both. What keeps the surfaces inside the high-pressure pump and the fuel injectors from wearing against one another is your diesel flowing through them — they're made to very fine tolerances.
The second job petrol doesn't do at all, and the first it does badly. It is thinner than diesel and takes away the protection your fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the knocking comes from.
Together, those make the shape of the trouble clear. Contact doesn't do the harm — circulation does. Where the petrol is only inside that tank, it's a problem of fuel, nothing more. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to your injectors beyond it.
How bad is petrol in a diesel? Four situations our engineers see in Broseley
Filled but never started — as good as it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol held in that tank alone, it is cleared and rinsed right where it stands, and nothing more is needed.
Your ignition switched on, or a brief start. Once primed, the system has drawn petrol out of your tank up to the fuel filter and the fuel lines. Usually nothing more than draining, flushing and sorting the filter, so still easy.
Some miles driven, and the pump has spent every one of them running on diluted fuel. How hard your car was driven counts as much as how far, and the work covers your tank, the lines, the fuel filter and clean fuel through the whole system. Short trips, like the school run to Broseley CofE Primary School, are one thing. Any mileage on the M54, under 5 miles from Broseley, means the motor has worked hard throughout, and a run to Wolverhampton, under 15 miles away, makes a very different job as well.
Driven till it protested. Rattling, an uneven idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer behaving like diesel. Leave it where it stops: a lay-by, a quiet street, the verge on Barber Street. The drain and flush-through still come first, and they take care of it: when a vehicle is pulled over quickly, lasting damage is very rare.
What Broseley drivers get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that guidance supposes.
Myth: a current diesel copes with a bit of petrol. If anything, the reverse. At higher pressure, through finer components: that's how a modern diesel moves its fuel, and so the protection counts for more, not less.
"It starts, it drives, and so there is no harm" — the myth that catches more people than any other. The motorist of a petrol motor fed diesel normally stops, because it will not run, and the harm stops there. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, while the pump grinds. Running isn't the same as fine.
An outdated workaround for a different issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." The petrol is still inside your tank after that, and whatever it has thinned is not put back.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, ready to go right back through the pump on your next start. Draining petrol into a can at the kerbside is also genuinely dangerous.
Petrol in a diesel: how does it take place?
It's seldom carelessness, and nobody does it on purpose. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol motor. That's how the forecourt makes it easy.
Habit and the car falling out of step is when it takes place. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps laid out differently. A train to catch, and a hurried fill en route to Telford Central. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to prevent petrol in a diesel on your next fill-up around Broseley
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what counts.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of vehicles state the fuel there.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key when a home has one of each. So mark it.
- It sounds silly and it works: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- 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.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that will not accept 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 inside your tank makes a weaker mix. What to do next doesn't change, though — still do not start the car.
Petrol already in a diesel in Broseley? Start here
In that case, there's just a short order of things. Do not fire it up, and do not switch the ignition on. If you are still at the forecourt — the nearest petrol station or anywhere else — ask the attendants to help you roll it clear of the petrol pump. Ring 0333 366 0103 next, with three answers — your fuel, the approximate volume, and whether it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a different fault — Broseley has a page just for it.
What makes one Broseley petrol in a diesel task cost more than the next
A fair single price does not exist here: four situations, four separate jobs. Mostly, your cost moves with which situation you're in. 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 was put in, how much, and whether it's run — three queries we ask before pricing, not after, for exactly that reason. Those answers are what change a range into one firm number.
About Broseley and where it is
Broseley is a small town in Shropshire, situated near the Ironbridge Gorge and the settlements of Benthall and Jackfield. Broseley sits at an elevation of around 155 metres, approximately 14.9 miles from Wolverhampton and 125.9 miles from London. Broseley has a population of around 5596 people, predominantly living in semi-detached housing. Broseley remains a residential community with a mix of old and new buildings.
Broseley and Shropshire: where our fuel drain cover reaches
Benthall, Jackfield and Ironbridge are among the places around Broseley that the same vans work, answering petrol in diesel call-outs across Broseley's TF postcode area. You need not bring the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Broseley: still at the pump?
Then you're in the best spot there can be. Keep it switched off, and ring.