Hillend: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry less than you probably are. Petrol resting in a diesel tank does nothing to the motor until something draws it through the system — the ignition priming the pump, the starter, or the drive itself. So the fair answer to the first query everyone in Hillend asks, "have I wrecked it?", is normally no. To keep it like that, ring Petrol in Diesel then leave the motor alone. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has spread, and ways to make sure you never do it again.
What petrol in a diesel does to your engine
On its way through a motor, diesel does two jobs. Before it combusts, it protects — and then it ignites. The high-pressure fuel pump and your injectors are made to extremely fine tolerances, and your diesel passing through them is what stops those surfaces from wearing against one another.
The second task petrol doesn't do at all, and the first it does badly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the blend to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Seen together, they show the shape the trouble has. It's circulation that causes the damage, not contact. Petrol in a tank is a fuel problem. The beginning of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors beyond it.
Hillend, petrol in a diesel: four cases, from mild to significant
The best case there can be: filled up, not once started. Being at a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With the petrol held in that tank alone, it's emptied and rinsed on the spot, and nothing more is needed.
A brief spell of running, or merely the ignition on. Once primed, the fuel system has pulled petrol from the tank up to the fuel filter and the lines. Still generally simple: drain, flush, and the filter dealt with.
Driven a few miles. Now the pump has spent these miles labouring on diluted fuel. How hard the car was driven matters as much as how far, and this work covers your tank, the lines, the fuel filter and fresh fuel through the whole circuit. On the school run to the local primary school, the mileage is small. Very different a second time: a run to Glasgow, under 15 miles away, or any miles on the M8, under 3 miles from Hillend, where your engine never stopped running hard.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. That is the motor telling you its fuel has stopped acting like diesel. Leave it where it has stopped: a lay-by, a quiet street, the verge on Caldercruix Road. The fuel drain and flush still go first, and they deal with it: if a car is stopped quickly, long-term damage is very uncommon.
Hillend people and that petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that advice assumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the reverse. A modern diesel sends its fuel through more precise components at higher pressure, which makes the protection matter more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol motor and it generally will not run, so the driver stops — and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, while the pump wears. Fine and running are not the same at all.
Not so: a two-stroke additive makes it safe to drive home. It was an old workaround, meant for another issue. None of what petrol weakened gets put back by it — and afterwards, the tank still holds that petrol.
If your engine has been run, part of the petrol is in your filter and your lines, not the tank — and your next start sends it right back through your pump. So the myth "drain the tank yourself and you're sorted" doesn't hold. Clearing petrol into a can by the roadside is also really dangerous.
How does petrol in a diesel take place?
No one does it on purpose, and it is rarely carelessness. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
The moment routine stops matching the car is the moment it occurs. Hire cars, courtesy cars, and motors that are new to you. Two motors on one driveway, one petrol, one diesel. The pumps in a different order on a familiar forecourt. A hurried fill on the way to Caldercruix with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it occurs. With rain, a call arriving, or a car full of children to deal with, your hand just does what it always has.
Hillend drivers: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust 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 your first fill: many motors state the fuel type there.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, in a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it works.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels come with a filler built to reject a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- Stop the moment you notice. Less petrol in that tank makes a weaker mixture. It doesn't change what to do next, which is still not to start the car.
Put petrol in a diesel around Hillend already?
The order of things is brief, then. Never crank it, and don't switch your ignition on. Yet on the forecourt, at BP or anywhere else? Ask the staff to help you push the vehicle clear of the petrol pump. Next, 0333 366 0103. We will ask what got in, about how much, and if it has been run.
If it was AdBlue and not petrol, say so. That's a separate problem — corrosion and deposits rather than lost lubrication — and it has its own page for Hillend.
One petrol in a diesel job around Hillend costs more than another. Why?
There is no fair single quote for this, since the four scenarios above are four separate jobs. The situation itself does most of the work of moving your cost. Beyond that it is the ratio — how much petrol was put in against how much your tank holds — and after that where your car is and whether a technician can get to it safely.
Ahead of any quote, not after, come three questions: your fuel that got in, its amount, and whether it's run. That is why. With the answers, you get a straight figure rather than a range.
About Hillend itself
Hillend is a suburban area situated on the shores of a lake in North Lanarkshire, with a mix of semi-detached housing and other residential properties. Hillend sits at an elevation of 191 metres, overlooking the surrounding countryside and lakes. Hillend is located near several other communities, including Caldercruix, Longriggend, and Plains, and is approximately 13.8 miles from Glasgow. Hillend has a population of around 1728 people, making it a small but established residential community.
Fuel drain cover around Hillend and across North Lanarkshire
Caldercruix, Longriggend and Plains are among the places near Hillend that the same teams work, answering petrol in diesel call-outs across Hillend's ML postcode area. The car does not need to move to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump in Hillend, still?
The best position there is, then — that's where you are. Turned off it remains; then ring.