Should You Worry? Petrol in a Diesel Car in Kirkcudbright
Far less than you probably are, provided it has not been started. Everyone in Kirkcudbright begins with "have I wrecked it?", and the honest answer is usually no: petrol resting in the tank of any diesel stays harmless until priming, cranking or driving pulls it into your fuel system. Keep it like that: leave your engine off then call Petrol in Diesel. Further down, you will find what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
What petrol in a diesel does to the engine
Two jobs fall to diesel on its route through a motor. It lubricates first, and only then does it burn. Built to extremely fine clearances, the injectors and the pump depend on the diesel flowing through them to stop their surfaces wearing against one another.
Of those two jobs, petrol handles the first badly and the second never. It's runnier than diesel and removes the lubrication the fuel system depends on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Seen together, they show what shape the trouble has. Contact does not do the harm — movement does. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, borne by your fuel, into the injectors downstream, which is why a pump that has worked on the petrol is where a mechanical issue starts.
Kirkcudbright, petrol in a diesel: four cases, from mild to significant
Fuelled up, never started. The best case there can be. Only that tank has petrol in it, so the job is emptying the tank and rinsing the system where the vehicle sits. This scenario can only truly occur on a forecourt: anywhere else, the car got there by being driven.
Started for a second, or only your ignition on. Your system has been bled, and so petrol has left that tank and got to the fuel filter and the fuel lines. Usually little more than clearing, purging and seeing to the filter, so still simple.
A couple of miles driven, and the pump has spent each of them labouring on diluted fuel. Tank, lines, filter, then fresh fuel put through the whole circuit: that is this work, and the way the car was driven counts as much as the miles. Short trips, such as the school run to the local primary school, are one thing. Any miles on the A74(M), under 50 miles from Kirkcudbright, means your engine has worked hard throughout, and a run to Carlisle, under 50 miles away, is a very different task as well.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The engine is telling you your fuel is no longer behaving like diesel. Pull up wherever you are — the verge on Bridge Street, a lay-by, a side street — and leave it where it is. What comes first is still the fuel drain and flush-through, and that deals with it, with lasting damage very unusual when a car is stopped quickly.
What Kirkcudbright motorists get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A bigger tank of the same mixture is all it gives, since topping up removes nothing. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise components: that is how a modern diesel handles its fuel, and so the protection counts for more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more motorists than any other. Any petrol motor fed diesel generally won't run, and so the driver stops and the damage stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, while your pump wears. 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 different fault. It does not put back what petrol has weakened, and the petrol is still in that tank later.
Myth: "Drain that tank yourself and you're sorted." After the motor has run, some of the petrol is no longer in that tank: it's in your filter and the fuel lines, and it goes straight back through the pump at the next start. Also, a can of petrol filled at the roadside is genuinely hazardous.
Why petrol in a diesel takes place at all
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol vehicle at all. The forecourt makes it easy, and the slip runs one way.
It happens when habit and the vehicle stop matching. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the driveway of the same household. A familiar forecourt with the pumps in a different order. Filling up in a rush en route to the nearest station, with a train to catch. A new-to-you diesel Renault Clio, its first fuelling, and a motorist used to petrol: exactly when it takes place. Add a back seat full of kids, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up in Kirkcudbright
- Green for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- In a motor you do not know, look inside the flap over your filler or at the cap before the first fill: plenty of motors print the fuel there.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Whilst you are thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to reject a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop reading the pump.
- As soon as you realise, stop: less petrol inside the tank means a weaker blend. What to do next does not change, though — still do not start the car.
Petrol already in a diesel in Kirkcudbright? Begin here
Short and simple, then, is the order of things. Leave it unstarted, with your ignition switched off too. Ask the attendants to help you push it clear of the pump if you are still at the forecourt, whether that is the nearest petrol station or somewhere else. Then call 0333 366 0103 and tell us what got in, about how much, and whether it has run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own Kirkcudbright page.
One petrol in a diesel job around Kirkcudbright costs more than another. Why?
Four separate jobs lie behind the four situations above — which is why there's no fair single price. Which of them you are in is chiefly what shifts your cost. Where your car is counts too, and whether a van can safely get to it, after the proportion of petrol to what your tank holds.
That's why our technicians ask three questions before costing rather than after: what was put in, how much, and if it has run. A range becomes a straight figure when the replies are in.
About Kirkcudbright
Kirkcudbright is a small town situated on the coast of Dumfries and Galloway in Scotland, with a population of around 3219 people. Kirkcudbright sits at a low elevation of approximately 10 metres above sea level, near the estuary of the River Dee. Kirkcudbright is characterised by its detached housing and is close to nearby places such as St Marys Isle and Tongland. Kirkcudbright is located near the Solway Coast, an area of natural beauty in southern Scotland.
Fuel drain cover in Kirkcudbright and across Dumfries and Galloway
Kirkcudbright sits in the DG postcode area, and our vans that answer petrol in diesel call-outs there work the places around it as well — St Marys Isle, Mutehill and Tongland among them. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places where we work.
Still at the pump in Kirkcudbright?
No position is better: that is where you now are. Keep it off. Phone.