Sandfields: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, provided it hasn't been started. Petrol resting in a diesel tank does nothing to the engine until something draws it through the system — your ignition priming your pump, the starter, or driving itself. So the honest answer to the first query anyone in Sandfields asks, "have I wrecked it?", is normally no. Petrol in Diesel is who to phone, with your motor left off, and so it stays that way. The remainder of this page explains 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.
What petrol in a diesel does to the engine
Diesel has two tasks on its way through a motor. It lubricates first, and only then does it burn. Your high-pressure pump and the fuel injectors are built to extremely fine clearances, and the diesel passing through them is what keeps those surfaces from wearing against each other.
The second task petrol does not do at all, and the first it does badly. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication the system hinges on, and any pump working on that mix is wearing itself.
The shape of the trouble is plain when you put those together. Contact doesn't do the harm — circulation does. A tank with petrol in it is a fuel fault. After your pump has been running on that petrol, a mechanical issue has begun: whatever is shed by a pump that's grinding is carried onward to your injectors with the fuel.
Petrol in a diesel in Sandfields: how bad is it? Four cases
The best case there is: filled up, never started. Only that tank has petrol in it, so the job is draining your tank and flushing your system where your car sits. This scenario can only truly take place at a forecourt: anywhere else, the vehicle got there by being driven.
Started for a second, or only your ignition on. Petrol has come out of your tank and reached the fuel filter and the fuel lines, since the fuel system has been primed. Usually little more than emptying, purging and sorting the filter, and so still simple.
Those few miles driven were your pump working on fuel thinned by petrol the whole way. Tank, lines, filter, then fresh fuel run through the whole circuit: that is the work, and the way your car was driven counts as much as the miles. A school run to the local primary school is one matter. Very different a second time: a run to Swansea, under 10 miles away, or any distance on the M4, under a mile from Sandfields, where your engine never stopped labouring hard.
It protested, 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 runs like diesel. Whether it is the verge on Southdown Road, a lay-by or a side street, stop there then leave it. What goes first is still the drain and flush-through, and that sorts it out, with lasting damage very uncommon if a car is pulled over early.
Stories Sandfields motorists hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A fuller tank of the same mixture is all you get, because topping up removes nothing. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Lubrication counts more on modern diesels, not less, since their fuel runs through more precise components at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that catches drivers. A petrol motor fed diesel generally won't run, so the motorist stops and the harm stops with them. While your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. A running engine doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. That petrol is still inside your tank after that, and whatever it has thinned isn't put back.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, waiting to go straight back through your pump on your next start. Also, a can of petrol drained by the roadside is truly hazardous.
Why petrol in a diesel happens at all
No one does it on purpose, and it's seldom carelessness. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol motor at all. So the mistake runs one way.
Habit and your car getting out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. A hurried fill en route to Baglan with a train to catch. Years of petrol vehicles behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Preventing petrol in a diesel next time you fill up in Sandfields
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is only a hint.
- Many motors state the fuel type inside the filler flap or on the cap, so check there on the first fill in a car you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a household with one of each.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away then keep your mind on the pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to block a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop reading the petrol pump.
- The moment you realise, stop: less petrol inside the tank means a thinner mix. What to do next does not change, though — still do not start it.
Sandfields: already put petrol in a diesel?
The order of things is brief, then. Leave it unstarted, with the ignition switched off too. The attendants on the forecourt — whether at Morrisons itself or wherever you filled up — will normally help roll it clear of the petrol pump if you ask. Phone 0333 366 0103 next, with three answers — the fuel, the approximate volume, and if it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different problem — Sandfields has a page all for it.
One petrol in a diesel job around Sandfields costs more than another. Why?
A fair single price doesn't exist here: four situations, four separate jobs. Which of them you are in is mostly what shifts the cost. Next it's the ratio — how much petrol got in against how much your tank takes — and after that where your car is and whether a van can get to it safely.
Ahead of any quote, not after, we ask three questions: the fuel that got in, its volume, and if it has run. That is why. A range turns into a straight figure when the replies are in.
About Sandfields and where it is
Sandfields is a coastal suburban area in Neath Port Talbot, situated near the mouth of the Afan River and close to the nearby towns of Aberavon and Port Talbot. Sandfields has a relatively low elevation of around 9 metres above sea level, reflecting its coastal location. Sandfields is characterized by its predominantly semi-detached housing stock, which is typical of many suburban areas in south Wales.
Across Neath Port Talbot and in Sandfields: fuel drain cover
Sandfields sits in the SA postcode area, and the teams that answer petrol in diesel jobs there work the locations around it as well — Aberavon, Baglan and Port Talbot among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our engineers drain, and the vehicle does not need to move to us.
In Sandfields and still at the petrol pump?
Then you're in the best position there can be. Switched off it stays; then phone.