Should You Worry? Petrol in a Diesel Car in Sighthill
Provided it has not been started, worry far less than you likely are. Petrol resting in a diesel tank does nothing to the motor until something draws it through the system — the ignition priming the pump, your starter, or driving itself. So the truthful answer to the first query anyone in Sighthill asks, "have I wrecked it?", is generally no. To leave the vehicle that way, ring Petrol in Diesel then leave the engine alone. The remainder of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
Petrol in a diesel: what does it do to the motor?
Diesel does two jobs on its way through a motor. Lubricating comes before burning; it does both. The high-pressure fuel pump and your injectors are designed to very fine gaps, and the diesel passing through them is what keeps those surfaces from grinding against each other.
Poorly at the first, not at all at the second: that's petrol. It's thinner than diesel and strips away the protection the fuel system rests on, so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the rattling comes from.
Combined, those leave the shape of the trouble plain. The harm is done by movement, not by contact. Petrol in a tank is a fuel fault. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors further along, which is why a pump that has worked on the petrol is where a mechanical problem begins.
How serious is petrol in a diesel? Four scenarios our technicians see in Sighthill
The best case there is: filled up, never started. That petrol is inside the tank and just the tank, and the job is a drain and a flush where your car stands. This is the one situation that can only truly happen on a forecourt, since anywhere else your car has been driven to get there.
Ignition on, or started for a second. Petrol has come out of that tank and got to the filter and the lines, since the fuel system has been primed. Still generally easy: drain, flush, and the filter dealt with.
Driven a couple of miles. Now the pump has spent those miles running on diluted fuel. How hard your car was driven matters as much as how far, and this work takes in your tank, the fuel lines, the filter and fresh fuel through the whole system. Short trips, like the school run to the local primary school, are one matter. Any miles on the M8, under a mile from Sighthill, means your engine working hard throughout, and a run to Edinburgh, under 5 miles away, makes a very different task as well.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you the fuel is no longer acting like diesel. Stop wherever you are — the verge on Bankhead Broadway, a lay-by, a side street — then leave it there. What comes first is still the fuel drain and flush, and that deals with it, with lasting damage very uncommon if a vehicle is stopped early.
Petrol in a diesel myths Sighthill motorists hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — that tank simply carries more of the same blend. The idea behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through finer parts: that is how a modern diesel handles its fuel, and so the protection matters more, not less.
"It starts, it drives, and so there is no harm" — the myth that catches most motorists than any other. The driver of a petrol engine fed diesel normally stops, since it will not run, and the damage stops there. While the pump wears, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Running doesn't mean fine.
Myth: a two-stroke additive lets you to drive home. It is an old workaround, supposed for another fault. The petrol is still inside your tank afterwards, and whatever it has diluted isn't put back.
The next start sends petrol back round your pump from the fuel lines and your filter, where some of it sits once the engine has run. That's why draining the tank yourself doesn't sort it — a myth. Besides, petrol emptied into a can by the road is truly hazardous.
Why petrol in a diesel happens so easily
It is seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol motor at all. So the mistake runs one way.
It occurs when routine and the car stop matching. Any motor that's new to you — a hire car, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to Edinburgh Park. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it occurs. Your hand does what it has always done when you add rain, a phone call or a back seat full of children.
Sighthill motorists: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: many cars state the fuel type there.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a household has one of each. So label it.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It sounds daft and it works.
- Put the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Some diesels come with a filler built to block a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- Less petrol makes a weaker mixture, and so stop as soon as you notice — while remembering that your next step is unchanged. It is still not to start the car.
Put petrol in a diesel around Sighthill already?
The order of things is short, then. Starting it is out, and so is switching on the ignition. Ask the attendants to help you push it clear of the pump if you are still on the forecourt, whether that is BP or somewhere else. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it has been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate fault — Sighthill has a page just for it.
What makes one Sighthill petrol in a diesel job cost more than the next
An honest single price doesn't exist here: four scenarios, four separate tasks. Chiefly, the cost shifts with which situation you are in. Two things come after that: the petrol that went in as a proportion of what that tank holds, then the place the vehicle is in and whether our van can get to it safely.
That is why our technicians ask three questions before pricing instead of after: what was put in, how much, and whether it's run. A range turns into a straight figure when the replies are in.
About Sighthill, for a moment
Sighthill is a suburban area in the City of Edinburgh, situated near the Water of Leith and approximately 4.6 miles west of Edinburgh's city centre. Sighthill sits at an elevation of around 65 metres, with the surrounding landscape dominated by the urban sprawl of the city. Sighthill is characterised by its predominantly flat-based residential housing, with nearby areas including Wester Hailes, South Gyle, and Broomhouse. Sighthill is home to a population of around 2561 people, according to recent estimates.
Sighthill and City of Edinburgh: where our fuel drain cover reaches
The teams answering petrol in diesel calls around Sighthill, in the EH postcode area, also work the places near it, Wester Hailes, South Gyle and Broomhouse included. The car doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Sighthill: still at the pump?
No position is better: that's where you are. Turned off it stays; then phone.