Petrol in a Diesel Car in Horselees: How Worried Should You Be?
Provided it has not been started, worry far less than you probably are. Petrol resting in a diesel tank does nothing to your engine until something pulls it through the system — the ignition priming the pump, your starter, or driving on its own. So the fair answer to the first query anyone around Horselees asks, "have I wrecked it?", is normally no. Keep it like that: leave the engine off then ring Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening again: that is the remainder of this page.
What petrol in a diesel does to the engine
On its way through a motor, diesel has two tasks. It lubricates to begin with, and after that does it burn. 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 built to very fine tolerances.
Of these two tasks, petrol manages the first badly and the second never. The knocking comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection the system depends on, and any pump working on such a mix is wearing itself.
The shape of the trouble is plain once you put those together. It's circulation that does the harm, not contact. A tank with petrol in it is a fuel fault. Once the pump has been running on that petrol, a mechanical fault has begun: anything shed by a pump that is grinding travels onward to the injectors with your fuel.
Four situations our engineers see around Horselees: how serious is petrol in a diesel?
Filled but not once started — as good as it gets. That petrol is in the tank and only your tank, and the task is a drain and a flush where your car stands. This is the one scenario that can only really take place on a forecourt, as anywhere else your car has been driven to get there.
Ignition on, or started for a second. The system has been bled, so petrol has left that tank and got to the filter and your lines. Normally nothing more than emptying, rinsing and seeing to the fuel filter, so still easy.
Those few miles on the road meant the pump labouring on fuel weakened by petrol the whole way. Tank, lines, filter, then clean fuel put through the entire system: that is this work, and the way your car was driven matters as much as the mileage. On the school run to Boughton-under-Blean and Dunkirk Primary School, the mileage is short. A run as far as Canterbury, under 10 miles away, is a very different task. So is any miles on the M2, under 3 miles from Horselees, where the engine has been running hard the whole time.
Driven on until it complained — knocking, smoke, an uneven idle, a soft throttle. The fuel is not behaving like diesel any more, and the engine is telling you. Leave it where it stops: a lay-by, a side street, the verge on Dunkirk Road North. The fuel drain and flush still come first, and they sort it out: when a vehicle is stopped quickly, lasting damage is very unusual.
Petrol in a diesel stories Horselees motorists hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. That advice supposes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A current diesel runs its fuel through smaller parts at higher pressure, which makes the lubrication count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no harm done." A petrol motor fed diesel generally won't run, and so the motorist stops 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 wears. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. The petrol is still inside your tank afterwards, and what it has thinned isn't put back.
Myth: "Drain the tank yourself and you're sorted." After your engine has been 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 your pump at the next start. It's also truly dangerous to drain petrol into a can at the roadside.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and no one 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 generally will not go into a petrol motor at all. The forecourt makes it easy, and the mistake runs one way.
It takes place when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. Two cars on one drive, one petrol, one diesel. The pumps in a different order on a well-known forecourt. A train to catch, and a rushed fill on the way to Selling. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. Throw in a back seat full of kids, a phone call or rain, and the hand takes over.
Horselees motorists: how to avoid petrol in a diesel next time
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Trust the label on the pump, not the colour.
- The first fill in a strange vehicle is the time to check the filler flap — inside it, or on the cap, many cars state the fuel to use.
- 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 mark it.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car needs its first tank. It seems silly. It does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a safety net, then keep checking the petrol pump.
- As soon as you realise, stop: less petrol in the tank means a weaker mixture. What to do next doesn't change, though — still do not fire it up.
Put petrol in a diesel in Horselees already?
The order of things is short, then. Starting it is out, and so is turning on the ignition. Ask the attendants to help you roll it clear of the pump if you are still at the forecourt, whether that is Gulf or somewhere else. Then phone 0333 366 0103 and tell us what went in, roughly how much, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate problem — Horselees has a page all for it.
What makes one Horselees petrol in a diesel task cost more than the next
There's no honest single price for this, because the four scenarios above are four separate tasks. Which of them you are in is chiefly what shifts the cost. The share counts next, meaning how much of that tank is petrol, followed by the position of the vehicle and whether getting to it is safe for our van.
That's why we ask three questions before costing instead of after: what got in, how much, and if it has run. Those answers change a range into a straight figure.
About Horselees
Horselees is a suburban area situated inland in Kent, approximately 5 miles from Canterbury and 49 miles from London, with an elevation of around 60 metres. Horselees has a population of around 1738 people and is characterised by semi-detached housing. Horselees is located near other local places such as Hickmans Green, Boughton Street, and Boughton under Blean. Horselees forms part of the wider residential area surrounding Canterbury.
Fuel drain cover across Kent, Horselees included
The teams answering petrol in diesel call-outs in Horselees, in the ME postcode area, also work the spots around it, Hickmans Green, Boughton Street and Boughton under Blean among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we work, and the car doesn't need to come to us.
Horselees: still at the pump?
Nothing beats it: that is where you are. Keep the car switched off, then ring.