Petrol in a Diesel Car in Brackenlands: How Worried Should You Be?
Provided it hasn't been started, worry far less than you probably are. Petrol sitting in a diesel tank does nothing to your motor until something pulls it through the fuel system — your ignition priming the pump, the starter, or the drive on its own. So the fair answer to the first question everyone in Brackenlands asks, "have I ruined it?", is generally no. To leave the vehicle like that, phone Petrol in Diesel and leave the engine alone. 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 a second time.
The engine and petrol in a diesel: what goes on
Two tasks fall to diesel on its route through a motor. Before it ignites, it protects — then it combusts. What stops the surfaces inside the high-pressure fuel pump and your injectors from wearing down against each other is the diesel passing through them — they are designed to extremely fine gaps.
Of these two tasks, petrol handles the first badly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is runnier than diesel and strips out the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that's where the rattling comes.
The shape of the trouble is plain once you put those together. Contact does not do the damage — movement does. All a tank with petrol in it amounts to is a fuel fault. After the pump has been running on that petrol, a mechanical issue has started: anything shed by a pump that's wearing down is carried onward to the fuel injectors with the fuel.
How bad is petrol in a diesel? Four situations our engineers see in Brackenlands
Fuelled, and never started: nothing beats it. Only that tank has petrol in it, so the task is draining that tank and rinsing the system where your car sits. This situation can only really take place on a forecourt: anywhere else, the vehicle got there by being driven.
The ignition turned on, or a brief start. Once primed, the system has pulled petrol from that tank as far as the filter and the lines. Usually nothing more than clearing, rinsing and seeing to your filter, and so still simple.
Those few miles on the road were the pump running on fuel diluted by petrol the whole way. Tank, lines, filter, then fresh fuel run through the entire system: that is this work, and the way the vehicle was driven counts as much as the distance. The school run to Wigton Nursery and Infant School is one matter. A run as far as Carlisle, under 15 miles away, is a very different task. So is any mileage on the M6, under 15 miles from Brackenlands, where your engine has been running hard throughout.
Driven until it protested. Rattling, an uneven idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer acting like diesel. Stop wherever you are — the verge on South Bank Close, a lay-by, a side street — then leave the vehicle where it is. Lasting damage is very unusual when a vehicle is stopped early, and the drain and flush-through that still go first sort it out.
Brackenlands motorists and the 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." Topping up takes out nothing; it gives you a bigger tank of the same mixture. The idea behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A current diesel can cope with a bit of petrol." Lubrication counts more on modern diesels, not less, because their fuel runs through smaller parts at higher pressure.
The myth that catches motorists out: if it starts and drives, it must be unharmed. A petrol engine fed diesel generally will not run, so the motorist stops and the harm stops with them. Whilst your pump wears, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Being able to run isn't the same as being fine.
An outdated fix for a distinct problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." The petrol is still in your tank afterwards, and whatever it has thinned is not put back.
The next start draws petrol back round your pump from the fuel lines and the filter, where some of it sits after the engine has run. That's why draining the tank yourself does not sort it — a myth. On top of that, petrol drained into a can by the road is genuinely hazardous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. A diesel nozzle generally won't go into a petrol motor, but the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and just in that direction.
The moment habit stops matching the car is the moment it takes place. Courtesy car, hire car, or a vehicle that's brand new. A household with one petrol and one diesel on the drive. The pumps in a different order on a familiar forecourt. A hurried fill en route to Wigton with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it occurs. With rain, a call coming in, or children to deal with, your hand just does what it always has.
Next time you fill up in Brackenlands: avoiding petrol in a diesel
- The label is what matters, so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Plenty of motors state the fuel inside your filler flap or on the cap, and so check there on the first fill in a motor you don't know.
- One of each in the house? Mark your key to the diesel — a coloured fob, a sticker — since meaning to remember isn't enough.
- Before the nozzle comes off the pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Daft, yes, yet it works.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to refuse a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a backstop, and keep reading the petrol pump.
- Spotting it mid-fill? Stop at once. A weaker blend results from less petrol inside your tank, but the next step stays the same: don't fire it up.
Petrol already in a diesel in Brackenlands? Begin here
The order of things is brief, then. Leave it unstarted, with the ignition off as well. Still at the forecourt, at BP or anywhere else? Ask the attendants to help you push the car clear of the pump. Then ring 0333 366 0103 and tell us what was put in, roughly how much, and whether it's run.
Corrosion and deposits are the issue with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Brackenlands page.
One petrol in a diesel job around Brackenlands costs more than another. Why?
There's no fair single price for this, since the four scenarios above are four different tasks. What shifts your cost is mostly which of them you are in. Where the car is counts too, and whether our van can safely reach it, after the ratio of petrol to what the tank holds.
Three queries come first, before quoting, instead of after — what got in, how much, has it run — and that is the reason. The replies change a range into a straight figure.
About Brackenlands
Brackenlands is a suburban area situated on the riverside in Cumbria, with an elevation of 52 metres above sea level. Brackenlands lies approximately 10 miles from Carlisle and 260 miles from London, making it a relatively remote but still accessible community. Brackenlands is characterized by its semi-detached housing and a population of around 1629 residents. Brackenlands is near other small places like Highmoor and High Longthwaite, and is also close to the historic area of Old Carlisle.
Fuel drain cover around Brackenlands and across Cumbria
Highmoor, High Longthwaite and Old Carlisle are among the spots near Brackenlands that the same vans work, answering petrol in diesel call-outs across Brackenlands's CA postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and the vehicle doesn't need to move to us.
At the petrol pump in Brackenlands, right now?
The best position there is, then — that is where you are. Phone, and keep it switched off.