Should You Worry? Petrol in a Diesel Car in White Houses
Probably less than you already are — provided nobody has started the car. Petrol resting in a diesel tank does nothing to your motor till something draws it through your fuel system — your ignition priming the pump, your starter, or the drive itself. So the fair answer to the first query everyone in White Houses asks, "have I wrecked it?", is generally no. Petrol in Diesel is who to call, with the engine kept off, and so it stays that way. The rest of this page sets out what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
The motor and petrol in a diesel: what goes on
On its way through an engine, diesel does two tasks. It lubricates first, and only then does it burn. What keeps the surfaces inside the high-pressure fuel pump and your injectors from grinding against one another is your diesel passing through them — they are designed to extremely fine tolerances.
Of those two jobs, petrol manages the first poorly and the second never. The rattling comes from petrol being made 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 system rests on, and any pump running on that mix is wearing itself.
Combined, those leave the shape of the problem clear. Contact doesn't do the harm — movement does. A tank with petrol in it is a fuel issue. After your pump has been working on that petrol, a mechanical issue has started: anything shed by a pump that's grinding is carried onward to the fuel injectors with your fuel.
Four scenarios our engineers see in White Houses: how serious is petrol in a diesel?
Filled up, and not started: no case is better. Just that tank has petrol in it, so the job is clearing the tank and purging the system where the vehicle stands. This situation can only truly happen on a forecourt: anywhere else, the car got there by being driven.
A moment's running, or just your ignition on. Once primed, your system has pulled petrol from that tank up to the fuel filter and your lines. Normally little more than draining, rinsing and sorting the filter, so still straightforward.
Those few miles driven meant the pump working on fuel weakened by petrol throughout. How hard the vehicle was driven counts as much as how far, and the work takes in the tank, your lines, the filter and fresh fuel through the whole system. On the school run to Bracken Lane Primary Academy, the distance is short. Any miles on the Doncaster By-Pass, under 10 miles from White Houses, means your engine working hard throughout, and a run to Lincoln, under 25 miles away, is a very different job too.
Driven on till it complained — knocking, smoke, a ragged idle, a dead throttle. That is the engine telling you its fuel no longer is behaving like diesel. Pull up wherever you are — the verge on Snowden Drive, a lay-by, a side street — and leave the car where it is. What comes first is still the fuel drain and flush, and that deals with it, with lasting damage very rare if a vehicle is pulled over quickly.
What White Houses motorists get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." A modern diesel sends its fuel through smaller components at higher pressure, which makes the protection count more, not less.
One myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor usually means a motor that will not run: the motorist stops, and so does the harm. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Being able to run isn't proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. What petrol has thinned stays diluted, and that petrol remains inside the tank regardless.
Myth: "Drain your tank yourself and you are sorted." After the engine has been run, some of the petrol is no longer in the tank: it is in your filter and the lines, and it goes right back through your pump on the next start. Besides, petrol cleared into a can by the road is genuinely risky.
Why petrol in a diesel occurs so easily
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
Routine and your car getting out of step is when it occurs. Hire cars, courtesy cars, and motors that are new to you. Two vehicles on one driveway, one petrol, one diesel. Your normal forecourt, its pumps suddenly in a different order. Racing for a train at Retford and fuelling up en route. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is exactly the moment it occurs. With rain, a call coming in, or a car full of children to deal with, your hand just does what it has always done.
Next time you fill up in White Houses: preventing petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is just a hint.
- The first fill in a strange motor is the time to check the filler flap — on it, or on the cap, plenty of motors state which fuel they take.
- One of each in the house? Label the key to your diesel — a bright fob, a sticker — because intending to remember isn't enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it does the trick.
- Tuck the phone away. This is an easy mistake to make while you are thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to block a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop checking the pump.
- As soon as you notice, stop: less petrol in the tank makes a thinner blend. What to do next doesn't change, though — still don't crank it.
Already put petrol in a diesel in White Houses?
Then, there is just a short order of things. Starting it is out, and so is turning on your ignition. The staff at the forecourt — whether at BP itself or wherever you filled up — will usually help push it away from the pump if you ask. Ring 0333 366 0103 next, with three facts — the fuel, the approximate amount, and if it's run.
Corrosion and deposits are the issue with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and read its own White Houses page.
White Houses petrol in a diesel jobs: why one costs more than another
The four situations above are four separate jobs, so no single quote for this would be fair. Which of them you are in is chiefly what shifts the cost. Where the car is matters too, and whether our van can safely get to it, after the proportion of petrol to what your tank holds.
Ahead of any quote, not after, come three queries: your fuel that got in, its quantity, and whether it has run. That is why. A range becomes a straight figure when the replies are in.
About White Houses, for a moment
White Houses is a locality in Nottinghamshire, situated on the riverside at a low elevation of around 23 metres. White Houses lies near the villages of Thrumpton and Newtown, and is close to the town of South Retford. White Houses has a population of approximately 1236 people, predominantly living in detached houses.
Across Nottinghamshire and around White Houses: fuel drain cover
White Houses rests in the DN postcode area, and our teams that answer petrol in diesel calls there work the locations near it as well — Thrumpton, Newtown and South Retford among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places we work, and the vehicle doesn't need to move to us.
White Houses: still at the petrol pump?
Then you're in the best place there can be. Ring, and keep it switched off.