Petrol in a Diesel Car in Bulford: How Worried Should You Be?
If it hasn't been started, you can worry far less than you probably are. Until the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just sits there and does no harm. Which makes the truthful reply to that first Bulford question — "have I ruined it?" — usually no. Keep it that way: leave your motor off then phone Petrol in Diesel. Below, this page sets out what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
The engine and petrol in a diesel: what happens
Passing through an engine, diesel does two things at the same time. It lubricates first, and only then does it burn. The high-pressure pump and your injectors are designed to extremely fine gaps, and the diesel passing through them is what stops those surfaces from wearing down against each other.
Petrol does the first task poorly and the second not at all. It's runnier than diesel and removes the lubrication your fuel system hinges on, so a pump running on a petrol mixture 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 rattling comes from.
Together, those make the shape of the problem plain. It is circulation that causes the harm, not contact. Petrol in the tank is a fuel problem. Once the pump has been labouring on that petrol, a mechanical problem has begun: whatever is shed by a pump that is wearing is carried onward to the fuel injectors with the fuel.
Bulford, petrol in a diesel: four cases, from mild to serious
The best case there can be: filled up, never started. The petrol is in your tank and only that tank, and the job is a drain and a flush where the car sits. This is the one scenario that can only truly occur at a forecourt, as anywhere else the vehicle has been driven to get there.
Started for a moment, or only the ignition on. With your system primed, the lines and filter now contain petrol that came from the tank. Usually little more than emptying, cleaning and sorting the fuel filter, so still straightforward.
Driven a few miles. Now your pump has spent these miles labouring on diluted fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's the work, and the way the car was driven counts as much as the mileage. Driving the kids to Bulford St Leonard's C of E (VA) Primary School is one sort of trip. Driving as far as Salisbury, under 10 miles away, makes a very different task — as does any distance on the M27, under 25 miles from Bulford, with the engine running hard the whole time.
Driven until it protested. Rattling, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Salisbury Road. What goes first is still the fuel drain and flush, and that takes care of it, with lasting damage very unusual when a vehicle is stopped early.
Petrol in a diesel stories Bulford drivers hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A bigger tank of the same mixture is all it gives, since topping up removes nothing. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Finer components and higher pressure are how a newer diesel runs its fuel, and that makes the lubrication count more, not less.
One myth that catches motorists off guard: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally leaves a motor that won't run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually fires up, ticks over and pulls away like nothing has happened — all while its pump is wearing. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated workaround for a different issue. That petrol is still inside your tank afterwards, and whatever it has thinned isn't put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in your filter and lines, waiting to go right back through your pump on your next start. Also, a can of petrol filled at the roadside is genuinely hazardous.
Petrol in a diesel: how does it occur?
On purpose? Never. Through carelessness? Seldom, 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 motor at all. The forecourt makes it easy, and the slip runs one way.
It takes place when routine and the car stop matching. Courtesy car, hire car, or a car that's brand new. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. Rushing for a train at Grateley and filling up en route. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you at the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up around Bulford
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is only a clue.
- The first fill in an unfamiliar car is the time to check the filler flap — inside it, or on the cap, many vehicles state which fuel they take.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, for a household with one of each.
- "Diesel", out loud, before you pick up the nozzle — each time a new or hired car gets its first tank. It seems silly. It works.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices exist for motors without one, and some diesels come with a filler that won't accept a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- Spotting it halfway? Stop there and then. A weaker mix results from less petrol inside your tank, yet your next step remains the same: don't fire it up.
Bulford: already put petrol in a diesel?
Then the order of things is short. Leave it unstarted, with your ignition switched off as well. Still at the forecourt, at Murco or anywhere else? Ask the attendants to help you push it clear of the pump. Call 0333 366 0103 next, with three answers — your fuel, the approximate quantity, and whether it has run.
If it was AdBlue and not petrol, say so. That's a different fault — corrosion and deposits rather than lost lubrication — and it has its own page for Bulford.
One petrol in a diesel task in Bulford costs more than another. Why?
An honest single quote does not exist here: four scenarios, four separate jobs. Chiefly, your cost shifts with which one you're in. Beyond that it's the proportion — how much petrol went in against how much the tank holds — and then where the vehicle is and whether our van can reach it safely.
That is why our technicians ask three queries before costing instead of after: what went in, how much, and if it's run. A range turns into a straight figure once the answers are in.
About Bulford and where it is
Bulford is a village situated on the banks of the River Avon in Wiltshire, with a mix of semi-detached housing and other residential properties. Bulford lies near the city of Salisbury, approximately 8.5 miles to the south, and is surrounded by other small villages such as Ratfyn and Durrington. Bulford has a population of around 1250 people and is located at an elevation of 77 metres above sea level. Bulford is also within commuting distance of London, being around 73.7 miles to the west of the capital.
Bulford and Wiltshire: where our fuel drain cover reaches
Ratfyn, Durrington and Brigmerston are among the spots around Bulford that the same vans work, answering petrol in diesel calls across Bulford's SP postcode area. Our technicians drain wherever your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the pump in Bulford?
Then, you could not be in a better position. Keep it off. Phone.