Should You Worry? Petrol in a Diesel Car in Beachley
Probably less than you are now — as long as nobody has started it. Until the ignition primes the pump, the starter cranks, or the vehicle is driven, petrol in a diesel tank simply sits there and does no harm. Which makes the truthful reply to the first Beachley query — "have I ruined it?" — normally no. Leave your engine off and phone Petrol in Diesel — that is how you keep it like that. Below, this page sets out what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to your engine?
Two jobs fall to diesel on its journey through a motor. It protects to begin with, and only then does it burn. Extremely fine clearances go into the fuel injectors and your high-pressure pump, and only your diesel flowing through stops those surfaces grinding together.
Badly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the mixture wearing itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the knocking.
Combined, those make the shape of the trouble plain. The damage is done by movement, not by contact. Where that petrol is only inside that tank, it is a fault of fuel, nothing more. Once your pump has been working on that petrol, a mechanical fault has begun: whatever is shed by a pump that's wearing travels downstream to the injectors with the fuel.
How serious is petrol in a diesel? Four scenarios our technicians see in Beachley
Filled up, never started. The best case there is. The petrol is inside that tank and only your tank, and the job is a drain and a flush where the vehicle stands. This is the one situation that can only truly occur at a forecourt, because anywhere else your car has been driven to get there.
Started for a second, or only your ignition on. The system has been bled, and so petrol has left the tank and got to the filter and your lines. Still generally easy: drain, flush, and your filter seen to.
Your pump has spent a couple of miles on weakened fuel — that's what driving the car does. Tank, lines, filter, then clean fuel put through the entire circuit: that is the work, and the way the car was driven matters as much as the distance. On the school run to Lift Offa's Mead, the distance is short. Getting as far as Bristol, under 15 miles away, makes a very different task — as does any miles on the Beachley Viaduct, under a mile from Beachley, with the engine running hard all the way.
Driven till it complained. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and the engine is saying so. Whether it is the verge on Beachley Road, a lay-by or a side street, stop where you are then leave it. What comes first is still the drain and flush, and that deals with it, with permanent damage very unusual if a car is pulled over quickly.
What Beachley drivers get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through smaller parts: that's how a current diesel moves its fuel, and so the lubrication counts more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no damage done." The motorist of a petrol engine fed diesel normally stops, since it will not run, and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, whilst the pump wears. Running does not mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an old fix for a separate fault. What petrol has weakened stays diluted, and the petrol stays in the tank anyway.
Myth: "Drain the tank yourself and you are sorted." After your engine has run, some of the petrol is no longer in that tank: it is in the fuel filter and your lines, and it goes straight back through your pump at the next start. On top of that, petrol drained into a can by the road is genuinely risky.
How it happens: petrol in a diesel
It's seldom carelessness, and no one does it on purpose. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it straightforward.
When habit and your car stop matching, it occurs. Courtesy car, hire car, or a car that's brand new. Households running one of each, petrol and diesel. A forecourt you know, but with its pumps laid out differently. A train to catch, and a rushed fill en route to Chepstow. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. The hand does what it has always done when you add rain, a phone call or a back seat full of children.
Next time you fill up around Beachley: preventing petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what counts.
- Plenty of vehicles state the fuel inside the filler flap or on the cap, and so check there on your first fill in a vehicle you do not know.
- Mark your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- 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 sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Add-on devices are available for motors without one, and some diesels come with a filler that will not take a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- Stop the moment you notice. Less petrol inside that tank means a weaker mixture. It does not change what to do next, which is still not to start the vehicle.
Beachley: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with the ignition off too. The attendants on the forecourt — whether at BP itself or wherever you filled up — will usually help push it away from the petrol pump if you ask. Then phone 0333 366 0103 and tell us what got in, roughly how much, and if it's run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and see its own Beachley page.
One petrol in a diesel job around Beachley costs more than another. Why?
The four scenarios above are four separate jobs, so no single quote for this would be honest. Which of them you are in is mostly what moves your cost. The share counts next, meaning how much of that tank is petrol, and then the position of the vehicle and whether reaching it is safe for our van.
Before any quote, not after, we ask three queries: the fuel that went in, the volume, and if it's run. That's why. With the replies, you get a straight figure rather than a range.
About Beachley, for a moment
Beachley is a small coastal village in Gloucestershire, situated near the Severn Estuary at an elevation of around 19 metres. Beachley lies close to the border with Wales and the nearby settlements of Bulwark and Sedbury. Beachley has a mix of housing types, with semi-detached homes being particularly prevalent. Beachley is located near the city of Bristol, which is approximately 11.6 miles away.
Across Gloucestershire and around Beachley: fuel drain cover
The vans answering petrol in diesel calls in Beachley, in the NP postcode area, also work the locations around it, Bulwark, Sedbury and Hardwick among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers drain, and the vehicle doesn't need to come to us.
In Beachley and still at the pump?
The best spot there is, then — that's where you are. Keep the car turned off, then ring.