Should You Worry? Petrol in a Diesel Car in Eskhill
Provided it hasn't been started, worry less than you probably are. "Have I wrecked it?" is the first thing anyone around Eskhill asks, and the honest answer is usually no, since petrol left in a diesel tank harms nothing until it's dragged through the fuel system — by ignition priming, by your starter, or by driving. Petrol in Diesel is who to call, with your engine kept off, and so it stays that way. The rest of this page sets out what petrol really does to a diesel, how to judge 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 engine?
Diesel has two jobs on its way through an engine. It ignites, and before it ignites it protects. Extremely fine clearances go into the fuel injectors and the high-pressure pump, and only the diesel running through stops those surfaces grinding together.
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, so a pump running on that mixture to wear itself. It's also 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 takes. It's circulation that causes the damage, not contact. A tank with petrol in it is a fuel fault. Once the pump has been working on that petrol, a mechanical fault has begun: whatever is shed by a pump that's wearing down travels downstream to the injectors with the fuel.
Petrol in a diesel around Eskhill: how bad is it? Four situations
Fuelled up, never started. The best case there is. At a forecourt, and genuinely only there, that petrol is still limited to the tank — since everywhere else your car was driven to get to it. The task is emptying and flushing on the spot.
Started for a second, or only your ignition on. Once primed, your system has drawn petrol out of your tank up to the fuel filter and your lines. Still generally simple: drain, flush, and the filter sorted.
Those few miles driven meant your pump working on fuel diluted by petrol throughout. Tank, lines, filter, then fresh fuel put through the whole system: that's the work, and the way your car was driven counts as much as the distance. On the school run to the local primary school, the miles is small. A run as far as Edinburgh, under 10 miles away, is a very different job. So is any mileage on the M8, under 10 miles from Eskhill, where the engine has been labouring hard throughout.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the engine reporting fuel that no longer acts like diesel. Pull up wherever you are — the verge on Eskhill, a lay-by, a side street — and leave it there. The fuel drain and flush-through still come first, and they deal with it: when a vehicle is pulled over early, long-term damage is very uncommon.
What Eskhill motorists get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed when you top up — the tank just holds more of the same blend. A diesel fuel system doesn't accept petrol by percentage in the way that advice assumes.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Finer components and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The driver of a petrol motor fed diesel usually has no choice but to stop, because it will not run, and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, whilst your pump grinds. Fine and running are not the same thing.
Not so: a two-stroke additive makes it safe to drive home. It is an old fix, meant for another problem. What petrol has weakened remains thinned, and that petrol stays in the tank regardless.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol sits in the fuel filter and lines, ready to go right back through your pump at your next start. It is also really dangerous to drain petrol into a can at the roadside.
Petrol in a diesel: how does it occur?
It's seldom 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 error runs one way.
It occurs when routine and the vehicle stop matching. A car that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Filling up in a hurry on the way to Curriehill, with a train to catch. A new-to-you diesel Volkswagen Tiguan, its first fuelling, and a driver accustomed to petrol: exactly when it happens. With rain, a call arriving, or children to deal with, the hand simply does what it always has.
Eskhill drivers: 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.
- Inspect your filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, in a household with one of each.
- It sounds daft and it works: on the first fill in a new or hired car, say "diesel" aloud 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 your phone away and keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices are available for the remainder. Count it as a safety net, then keep checking the petrol pump.
- Stop as soon as you notice. Less petrol in your tank makes a weaker mixture. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel in Eskhill already?
Then the order of things is short. Don't crank it, and do not turn the ignition on. Ask the staff to help you roll it clear of the pump if you are still at the forecourt, whether that's Tesco or somewhere else. Then phone 0333 366 0103 and tell us what got in, about how much, and whether it's run.
Say so if it was AdBlue instead of petrol: it is a different fault, with its own page for Eskhill, since AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task around Eskhill costs more than another
The four scenarios above are four separate tasks, so no single price for this would be honest. What shifts your cost is chiefly which of them you're in. Two things follow that: the petrol that got in as a share of what your tank takes, then the spot the car is in and whether a van can reach it safely.
That is why our technicians ask three queries before costing rather than after: what was put in, how much, and whether it has run. Those replies turn a range into a straight figure.
About Eskhill, briefly
Eskhill is a suburban area situated on the riverside in Midlothian, with a mix of terraced housing and other residential properties. Eskhill sits at an elevation of 192 metres, close to the nearby towns of Loanburn and Penicuik, and is approximately 8.5 miles from Edinburgh. Eskhill is part of the wider commuter belt around Edinburgh, with many residents making the short journey to the city for work or leisure. Eskhill has a population of around 5546 people, living in a range of housing types, predominantly terraced homes.
Fuel drain cover across Midlothian, Eskhill included
Eskhill sits in the EH postcode area, and the teams that answer petrol in diesel call-outs there work the spots around it as well — Loanburn, Penicuik and Kirkhill among them. The car does not need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump in Eskhill, right now?
Then, you couldn't be in a better spot. Call, and keep it switched off.