Woodfalls: Petrol in a Diesel Car? How Worried to Be
If it has not been started, you can worry less than you likely are. Petrol resting in a diesel tank does nothing to the engine until something draws it through the fuel system — the ignition priming the pump, your starter, or driving itself. So the fair answer to the first query everyone around Woodfalls asks, "have I ruined it?", is generally no. Leave your engine off and phone Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and ways to make sure you never repeat it.
What petrol in a diesel does to the engine
Two tasks fall to diesel on its route through a motor. It lubricates first, and after that does it burn. Built to extremely fine gaps, the fuel injectors and the pump rely on your diesel moving through them to stop their surfaces wearing against one another.
Badly at the first, not at all at the second: that is petrol. A pump working on a petrol mix is wearing itself out, because petrol is thinner than diesel and takes away the protection the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any knocking comes.
Combined, those make the shape of the problem plain. It's movement that does the harm, not contact. Any tank with petrol in it is a fuel problem. After your pump has been working on that petrol, a mechanical fault has begun: whatever is shed by a pump that is grinding is carried downstream to the injectors with the fuel.
Four scenarios we see around Woodfalls: how serious is petrol in a diesel?
Filled up, never started. The best case there can be. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol kept inside your tank alone, it is drained and purged right where it stands, and nothing more is needed.
Ignition on, or started for a second. With the fuel system primed, the fuel lines and filter now contain petrol that has come from that tank. Still usually straightforward: drain, flush, and the filter dealt with.
Those few miles driven meant your pump labouring on fuel thinned by petrol the whole way. How hard the car was driven counts as much as how far, and the work takes in your tank, the fuel lines, your filter and clean fuel through the entire system. The school run to Hale Primary School is one thing. A run as far as Salisbury, under 10 miles away, is a very different task. So is any distance on the M27, under 10 miles from Woodfalls, where the engine has been running hard throughout.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. What you are hearing is your motor signalling fuel that no longer behaves like diesel. Whether it's the verge on Whiteshoot, a lay-by or a side road, stop where you are and leave it. Permanent damage is very unusual when a car is pulled over quickly, and the fuel drain and flush that still come first take care of it.
Woodfalls motorists and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — the tank simply carries more of the same mixture. The assumption behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and closer to the reverse. Smaller components and higher pressure are how a newer diesel runs its fuel, and that makes the protection count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Feed diesel to a petrol motor and it usually won't run, and so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it generally fires up, ticks over and pulls away like nothing has happened — all while its pump wears. Fine and running are not the same thing.
Myth: a two-stroke additive lets you to drive home. It is an old fix, supposed for another issue. It doesn't put back what petrol has thinned, and that petrol is still inside that tank later.
The next start sends petrol back round your pump out of the lines and your filter, where some of that ends up after the engine has been run. That is why draining your tank yourself doesn't sort it — a myth. On top of that, petrol drained into a can by the road is truly hazardous.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Seldom, if ever. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol car. That's how the forecourt makes it easy.
It takes place when routine and the car stop matching. Courtesy car, hire car, or a vehicle that is brand new. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. A hurried fill on the way to Dean with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. With rain, a call arriving, or children to deal with, your hand just does what it always has.
Next time you fill up in Woodfalls: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what matters.
- The first fill in a strange motor is the time to check the filler flap — on it, or on the cap, plenty of cars state the fuel to use.
- 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 intending to remember.
- It sounds daft and it works: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a safety net, not a reason to stop checking the petrol pump.
- Less petrol means a weaker mixture, so stop the moment you notice — though remembering that the next step is unchanged. It is still not to start it.
Petrol already in a diesel in Woodfalls? Begin here
Then the order of things is short. Don't crank it, and do not turn your ignition on. The staff on the forecourt — whether at Esso itself or wherever you filled up — will usually help roll it clear of the petrol pump if you ask. What was put in, about how much, and if it has run: tell us those when you phone 0333 366 0103.
Corrosion and deposits form the issue with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Woodfalls page.
What makes one Woodfalls petrol in a diesel task cost more than the next
Four separate tasks sit behind the four situations above — which is why there's no fair single quote. Which of them you are in is mostly what shifts the cost. Beyond that it's the proportion — how much petrol was put in against how much that tank holds — and after that where the car is and whether a technician can get to it safely.
That is why we ask three queries before quoting rather than after: what was put in, how much, and whether it has run. Those answers are what turn a range into one firm number.
About Woodfalls itself
Woodfalls is a small village in Hampshire, situated inland at an elevation of 112 metres, approximately 7 miles from Salisbury. Woodfalls has a population of around 572 people and is characterised by predominantly detached housing. Woodfalls is located near other small settlements such as North Charford and Hatchet Green, and is about 78 miles from London.
Across Hampshire and around Woodfalls: fuel drain cover
Woodfalls rests in the SP postcode area, and the vans that answer petrol in diesel calls there work the locations around it as well — North Charford, Hatchet Green and Bohemia among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots we drain, and your vehicle doesn't need to move to us.
Still at the petrol pump in Woodfalls?
The best position there is, then — that is where you are. Keep it off. Call.