How Worried Should You Be? Petrol in a Diesel Car in Thornton
Likely less than you are now — provided nobody has started the vehicle. Till the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just waits there and does nothing. Which makes the truthful reply to the first Thornton question — "have I ruined it?" — normally no. Keep it like that: leave the engine off and call Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never do it again.
Inside your engine: what petrol in a diesel does
Diesel has two jobs on its way through a motor. It burns, and before it burns it lubricates. What keeps the surfaces inside your high-pressure pump and the fuel injectors from wearing down against each other is your diesel flowing through them — they are made to extremely fine gaps.
Petrol handles the first task poorly and the second not at all. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and strips out the protection your fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that's where the rattling starts.
Put these together and the shape of the problem is clear. It is movement that does the damage, not contact. Where that petrol is only inside the tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds goes on, carried by your fuel, into the fuel injectors further along, which is why a pump that has been working on that petrol is where a mechanical issue starts.
Four situations we see in Thornton: how bad is petrol in a diesel?
Filled but not once started — the best it gets. That petrol is inside your tank and just that tank, and the task is a drain and a flush where the vehicle sits. This is the one scenario that can only truly happen at a forecourt, because anywhere else the vehicle has been driven to get there.
A brief spell of running, or merely the ignition on. With your system primed, your lines and filter now contain petrol that has come from the tank. Usually little more than clearing, cleaning and sorting your filter, so still easy.
Those few miles on the road meant your pump working on fuel weakened by petrol throughout. Tank, lines, filter, then clean fuel run through the entire circuit: that is this work, and the way the car was driven counts as much as the miles. The school run to Horncastle Primary School is one matter. Any distance on the M180, under 50 miles from Thornton, means your engine has worked hard throughout, and a run to Lincoln, under 25 miles away, is a very different job as well.
Driven until it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is your motor signalling fuel that no longer runs like diesel. Stop wherever you are — the verge on Church Lane, a lay-by, a side street — then leave the vehicle where it is. Permanent damage is very uncommon when a vehicle is stopped early, and the fuel drain and flush-through that still go first take care of it.
Thornton people and the petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you are left with a fuller tank, still the same mix. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance supposes.
If anything, the opposite is true. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through more precise components: that's how a current diesel moves its fuel, so the lubrication matters for more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up most drivers than any other. A petrol motor fed diesel normally will not run, and so the driver stops and the damage stops with them. Whilst the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. None of what petrol weakened is put back by it — and afterwards, that tank still holds that petrol.
Myth: "Drain your tank yourself and you are sorted." Once the engine has run, some of that petrol is no longer in the tank: it's in the fuel filter and your lines, and it goes right back through your pump on the next start. It's also really dangerous to drain petrol into a can by the kerbside.
Why petrol in a diesel takes place so easily
A careless moment is seldom the cause, and no one means to do it. A diesel nozzle mostly won't fit a petrol vehicle, but the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error easy, and just in one direction.
Routine and your car falling out of step is when it occurs. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the drive. Your ordinary forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill on the way to Metheringham. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel at your next fill-up in Thornton
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on each forecourt. The label is what counts.
- The first fill in an unfamiliar car is the time to check the filler flap — on it, or on the cap, plenty of cars state which fuel to use.
- Label the 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.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems daft and it does the trick.
- Tuck your phone away. This is an easy mistake to make whilst you are thinking about something else.
- Some diesels have a filler designed to reject a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Spotting it mid-fill? Stop at once. A thinner mix follows from less petrol inside the tank, but your next step stays the same: do not fire it up.
Put petrol in a diesel around Thornton already?
The order of things is short, then. Do not switch your ignition on, and do not crank it. Still at the forecourt, at Richard Dear/Total or anywhere else? Ask the staff to help you push the vehicle clear of the pump. Phone 0333 366 0103 next, with three answers — your fuel, the rough volume, and whether it has run.
Corrosion and deposits form the problem with AdBlue, whereas petrol means lost protection. So if it was AdBlue, say so — and read its own Thornton page.
What makes one Thornton petrol in a diesel job cost more than the next
The four situations above are four different tasks, so no single quote for this would be fair. Mostly, the cost shifts with which situation you're in. Where the car is counts too, and whether a van can safely get to it, after the ratio of petrol to what your tank takes.
Ahead of any quote, not after, we ask three queries: your fuel that was put in, the quantity, and if it has run. That's why. A range becomes a straight figure when those replies are in.
About Thornton itself
Thornton is a small hamlet in Lincolnshire, situated on the riverside at an elevation of 44 metres, with detached housing being the predominant type of accommodation. Thornton lies near the villages of Martin, Langton, and Dalderby, and is approximately 16.8 miles from the city of Lincoln. Thornton is part of the wider East Midlands region, with London being around 116.4 miles to the south. Thornton has a population of around 603 residents.
Thornton and Lincolnshire: where our fuel drain cover runs
Thornton rests in the LN postcode area, and our teams that answer petrol in diesel call-outs there work the locations near it as well — Martin, Langton and Dalderby among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places we drain, and your car does not need to move to us.
At the petrol pump around Thornton, right now?
Then you are in the best place there is. Switched off it stays; then call.