Clayton Green: Petrol in a Diesel Car? How Worried to Be
Likely less than you already are — provided no one has started the vehicle. Petrol resting in a diesel tank does nothing to your motor till something pulls it through your fuel system — your ignition priming your pump, your starter, or the drive itself. So the honest answer to the first query everyone in Clayton Green asks, "have I ruined it?", is generally no. Leave your engine off and call Petrol in Diesel — that keeps it that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and ways to make sure you never repeat it.
The motor and petrol in a diesel: what happens
Two jobs fall to diesel on its route through a motor. It ignites, and before it ignites it protects. Extremely fine tolerances go into your injectors and the high-pressure fuel pump, and only the diesel flowing through stops those surfaces grinding together.
Petrol handles the first task badly and the second not at all. The knocking comes from petrol being designed not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the system rests on, and any pump working on such a mixture is wearing itself.
The shape of the trouble is plain when you put those together. It's movement that does the damage, not contact. All a tank with petrol in it amounts to is a fuel problem. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream.
How serious is petrol in a diesel? Four scenarios our technicians see around Clayton Green
Filled up, never started. The best case there can be. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held in the tank alone, it's cleared and flushed on the spot, and nothing more is needed.
Your ignition turned on, or a short start. Once primed, the system has drawn petrol out of the tank up to the fuel filter and the fuel lines. That is normally still a simple task — a drain, a flush, and your filter dealt with.
Some miles driven, and your pump has spent each of them labouring on thinned fuel. Miles is only half of that; how hard it was driven matters equally. Either way this work runs to your tank, the lines, your filter and fresh fuel through the whole system. The school run to Clayton-le-Woods Manor Road Primary School is one thing. Any distance on the M61, under a mile from Clayton Green, means the engine working hard throughout, and a run to Preston, under 5 miles away, is a very different job too.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The fuel is not acting like diesel any more, and the engine is saying so. Whether it is the verge on Kiln Croft, a lay-by or a side road, stop where you are and leave it. The fuel drain and flush-through still come first, and they deal with it: if a vehicle is stopped early, permanent damage is very uncommon.
What Clayton Green people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mix. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through more precise parts: that's how a newer diesel handles its fuel, and so the lubrication matters for more, not less.
"It starts, it drives, and so no harm done" — the myth that catches most drivers than any other. A petrol motor fed diesel usually won't run, so the driver stops and the harm stops with them. Feed petrol to a diesel and it generally fires up, idles and pulls away like nothing has happened — all while its pump wears. A running engine does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. It does not put back what petrol has diluted, and that petrol is still inside that tank after that.
The next start draws petrol back round the pump out of the fuel lines and the filter, where some of that sits once the motor has been run. That is why a DIY tank drain doesn't sort it — a myth. Clearing petrol into a can at the kerbside is also really hazardous.
Why petrol in a diesel takes place so easily
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol vehicle at all. So the error runs one way.
The moment routine stops matching the car is the moment it takes place. Courtesy car, hire car, or a motor that is new. Two motors on one driveway, one petrol, one diesel. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill on the way to Leyland. A new-to-you diesel Renault Clio, its first fuelling, and a motorist used to petrol: precisely when it occurs. Add rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
How to avoid petrol in a diesel on your next fill-up around Clayton Green
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Read the pump's label; the colour is just a clue.
- Inspect your filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on your first fill in a vehicle you don't know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key when a house has one of each. So mark it.
- Before the nozzle comes off the pump the first time you fill a hired or new car, say "diesel" aloud. Daft, yes, but it works.
- Tuck the phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices exist for vehicles without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Noticing it halfway? Stop at once. A weaker blend follows from less petrol inside that tank, but your next step stays the same: do not start the car.
Clayton Green: already put petrol in a diesel?
Then the order of things is brief. Starting it is out, and so is switching on your ignition. The attendants on the forecourt — whether at Shell itself or wherever you filled up — will normally help push it clear of the pump if you ask. What got in, roughly how much, and whether it's run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a different fault, with its own page for Clayton Green, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task in Clayton Green costs more than another
An honest single price does not exist here: four scenarios, four separate jobs. Which of them you are in is chiefly what shifts your cost. Two things follow that: the petrol that got in as a share of what your tank takes, then the spot your car is in and whether a technician can get to it safely.
That is why our engineers ask three queries before quoting instead of after: what got in, how much, and if it's run. The replies turn a range into a straight figure.
About Clayton Green itself
Clayton Green is a suburban area in Lancashire, situated near the River Lostock and close to the city of Preston. Clayton Green has a mix of housing types, but is predominantly characterised by detached homes. Clayton Green is located near several other communities, including Clayton Brook and Clayton-le-Woods, and is about 4.5 miles from Preston city centre. Clayton Green sits at an elevation of around 86 metres above sea level.
Fuel drain cover across Lancashire, Clayton Green included
Clayton Brook, Cuerden and Clayton-le-Woods are among the spots near Clayton Green that the same vans work, answering petrol in diesel calls across Clayton Green's PR postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and your car doesn't need to move to us.
In Clayton Green and still at the petrol pump?
Nothing beats it: that's where you now are. Keep it switched off, then ring.