How Worried Should You Be? Petrol in a Diesel Car in Overton
Far less than you probably are, provided it hasn't been started. "Have I ruined it?" is the first thing anyone around Overton asks, and the truthful answer is usually no, because petrol resting in a diesel tank harms nothing till it is dragged through the system — by ignition priming, by your starter, or by driving. Leave your motor off and phone Petrol in Diesel — that keeps it like that. Read on for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and the way to make sure you never do it again.
Petrol in a diesel: what does it do to your engine?
Diesel has two tasks on its way through an engine. It combusts, and before it combusts it protects. Very fine gaps go into your injectors and the high-pressure fuel pump, and only your diesel flowing through stops their surfaces grinding together.
The second task petrol doesn't do at all, and the first it does badly. It's thinner than diesel and strips away the lubrication your fuel system rests on, and 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 reverse of what a diesel needs from its fuel. That's where the rattling comes from.
Put those together and the shape of the issue is plain. The damage is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel fault. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
How bad is petrol in a diesel? Four situations our engineers see in Overton
Filled up, and never started: no case is better. Only the tank has petrol in it, so the task is draining the tank and purging the system where the car stands. This scenario can only really occur on a forecourt: anywhere else, the vehicle got there by being driven.
Started for a moment, or just your ignition on. Petrol has left that tank and reached your filter and the lines, since the system has been bled. Normally nothing more than draining, rinsing and seeing to the fuel filter, and so still simple.
Your pump has spent a couple of miles on weakened fuel — that is what driving it meant. Tank, lines, filter, then fresh fuel put through the entire circuit: that's this work, and the way the car was driven counts as much as the mileage. A school run to Overton Church of England Primary School is one matter. Very different once more: a trip to Winchester, under 15 miles away, or any miles on the M3, under 5 miles from Overton, where the engine never stopped running hard.
Driven on till it protested — clattering, smoke, an uneven idle, a dead throttle. The fuel is not acting like diesel any more, and your engine is saying so. Stop wherever you are — the verge on Kingsclere Road, a lay-by, a side street — and leave the car there. The drain and flush-through still come first, and they deal with it: when a car is stopped quickly, long-term damage is very unusual.
Petrol in a diesel stories Overton motorists hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. Percentage is not how a diesel fuel system tolerates petrol, however much that guidance assumes.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that is how a modern diesel handles its fuel, and so the lubrication matters for more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. The driver of a petrol motor fed diesel normally stops, because it will not run, and the harm stops with them. A diesel fed petrol usually starts, idles and drives away as if nothing has happened, whilst the pump grinds. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an old workaround for a distinct problem. None of what petrol weakened is put back by it — and afterwards, the tank still holds that petrol.
Myth: "Drain that tank yourself and you're sorted." Once your engine has been run, some of that petrol is no longer in that tank: it is in the fuel filter and the fuel lines, and it goes straight back through the pump at your next start. On top of that, petrol emptied into a can by the road is truly risky.
How does petrol in a diesel happen?
Nobody does it on purpose, and it is seldom carelessness. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol car at all. The forecourt makes it simple, and the error runs one way.
The moment routine stops matching your car is the moment it occurs. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a well-known forecourt. Racing for a train at the nearest station and filling up en route. Precisely the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Add a back seat full of children, a phone call or rain, and habit takes over.
How to prevent petrol in a diesel on your next fill-up in Overton
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what counts.
- Plenty of vehicles state the fuel type inside the filler flap or on the cap, and so check there on your first fill in a car you don't know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So mark it.
- It seems daft and it works: on your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- While you're thinking about something else, this is an easy mistake to make — so put the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop reading the pump.
- Less petrol makes a thinner mix, and so stop as soon as you notice — though remembering that the next step is unchanged. It is still not to crank it.
Overton: already put petrol in a diesel?
Then the order of things is short. Starting it is out, and so is switching on the ignition. If you're still at the forecourt — Whitchurch Filling Station or anywhere else — ask the staff to help you push it clear of the petrol pump. Phone 0333 366 0103 next, with three answers — your fuel, the rough quantity, and if it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different issue — Overton has a page all for it.
What makes one Overton petrol in a diesel job cost more than the next
Four different tasks lie behind the four scenarios above — which is why there's no fair single price. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that went in as a share of what that tank takes, then the place the car is in and whether our van can get to it safely.
Before any quote, not after, we ask three queries: your fuel that got in, the amount, and whether it has run. That's why. The replies turn a range into a straight figure.
About Overton and its setting
Overton is a village situated on the banks of the River Test in Hampshire, with a mix of terraced housing and other residential properties. Overton sits at an elevation of 87 metres, approximately 12.8 miles from the city of Winchester. Overton is located near other small villages such as Foxdown, Southington, and Lynch, and is about 52.2 miles from London.
Overton and Hampshire: where our fuel drain cover reaches
Foxdown, Southington and Lynch are among the locations near Overton that the same teams work, answering petrol in diesel calls across Overton's RG postcode area. You need not bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places we drain.
In Overton and still at the petrol pump?
The best spot there is, then — that's where you are. Switched off it remains; then ring.