How Worried Should You Be? Petrol in a Diesel Car in Whaddon
Far less than you likely are, provided it has not been started. Petrol sitting in a diesel tank does nothing to your engine till something draws it through the system — the ignition priming your pump, the starter, or driving itself. So the truthful answer to the first question anyone around Whaddon asks, "have I ruined it?", is generally no. Petrol in Diesel is who to call, with the engine left off, so it stays that way. Below, this page sets out what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you again.
What petrol in a diesel does to your engine
Diesel does two tasks on its way through a motor. Lubricating comes before burning; it does both. What keeps the surfaces inside the high-pressure fuel pump and the injectors from wearing against one another is your diesel passing through them — they are made to extremely fine tolerances.
The second task petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump running on that mixture wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the rattling.
Put these together and the shape of the issue is clear. It's circulation that does the harm, not contact. All a tank with petrol in it amounts to is a fuel problem. After the pump has been working on that petrol, a mechanical problem has started: whatever is shed by a pump that's wearing down is carried downstream to your injectors with the fuel.
Petrol in a diesel in Whaddon: how bad is it? Four cases
Filled but not once started — the best it gets. On a forecourt, and really only there, that petrol is still limited to your tank — since everywhere else the car was driven to get to it. The task is draining and purging on the spot.
A brief spell of running, or just your ignition on. With your system primed, your lines and filter already contain petrol that has come from the tank. That's normally still a simple task — a drain, a flush, and the fuel filter dealt with.
Those few miles driven meant the pump working on fuel thinned by petrol throughout. Tank, lines, filter, then clean fuel put through the entire circuit: that is this work, and the way the vehicle was driven matters as much as the mileage. On the school run to Alderbury and West Grimstead Church of England Primary School, the mileage is small. A run as far as Salisbury, under 5 miles away, is a very different job. So is any miles on the M27, under 10 miles from Whaddon, where the motor has been running hard throughout.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The fuel is not behaving like diesel any more, and your engine is telling you. Stop on the spot — on the verge on Grimstead Road, at the kerb, down a side road — and do not move it. The fuel drain and flush still come first, and they take care of it: if a vehicle is stopped quickly, long-term damage is very uncommon.
Petrol in a diesel stories Whaddon drivers hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A fuller tank of the same mixture is all you get, because topping up removes nothing. That guidance presumes a diesel fuel system handles petrol by percentage. It does not.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." A newer diesel sends its fuel through smaller parts at higher pressure, which makes the protection count more, not less.
This is the one that catches people. Myth: "If it starts and drives, there's no damage done." A petrol engine fed diesel generally will not run, and so the driver stops and the damage stops with them. Feed petrol to a diesel and it generally starts, ticks over and drives away like nothing happened — all the while its pump wears. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a different fault. It does not put back what petrol has thinned, and the petrol is still in the tank afterwards.
The next start draws petrol back round the pump out of your lines and the fuel filter, where some of it ends up once the engine has run. That's why draining your tank yourself doesn't sort it — a myth. Also, a can of petrol filled at the roadside is genuinely hazardous.
How petrol ends up: petrol in a diesel
It is seldom carelessness, and nobody does it on purpose. A diesel nozzle generally won't go into a petrol vehicle, but the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and only in that direction.
It takes place when habit and the vehicle stop matching. A new motor, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. Your normal forecourt, its pumps now in a different order. Filling up in a rush en route to Dean, with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a motorist accustomed to petrol: exactly when it takes place. With rain, a call arriving, or a car full of children to deal with, the hand simply does what it always has.
Next time you fill up around Whaddon: preventing petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is only a clue.
- The first fill in a new car is the time to check the filler flap — on it, or on the cap, plenty of cars state the fuel to use.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key when a house has one of each. So label it.
- It sounds silly and it works: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Mistakes like this are simple to make whilst your mind is on something else, and so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Spotting it mid-fill? Stop there and then. A thinner mix results from less petrol inside your tank, yet the next stage stays the same: do not crank it.
Already put petrol in a diesel in Whaddon?
Then the order of things is short. Do not turn your ignition on, and do not fire it up. If you are still on the forecourt — Tesco or anywhere else — ask the attendants to help you push the car clear of the pump. Ring 0333 366 0103 next, with three facts — the fuel, the rough volume, and whether it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate fault — Whaddon has a page all for it.
Whaddon petrol in a diesel tasks: why one costs more than another
Four separate tasks sit behind the four scenarios above — which is why there's no fair single quote. Which of them you're in is mostly what shifts the cost. Where the vehicle is matters too, and whether a van can safely get to it, after the ratio of petrol to what that tank holds.
Three questions come first, before quoting, rather than after — what went in, how much, has it run — and that is the reason. A range turns into a straight figure once the replies are in.
About Whaddon itself
Whaddon is a village in Wiltshire, situated on the banks of the River Avon at an elevation of around 75 metres. Whaddon lies near the city of Salisbury, approximately 4 miles to the east, and is surrounded by nearby villages such as Alderbury and West Grimstead. Whaddon has a population of around 662 people, predominantly living in detached houses. Whaddon is located in the South West region of England, about 76 miles west of London.
Fuel drain cover in Whaddon and across Wiltshire
Whaddon waits in the SP postcode area, and our teams that answer petrol in diesel jobs there work the places around it as well — Alderbury, West Grimstead and Shute End among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our engineers work, and the vehicle does not need to move to us.
At the pump around Whaddon, still?
Then you are in the best spot there is. Keep the vehicle switched off, and ring.