How Worried Should You Be? Petrol in a Diesel Car in Upper Lochton
Less than you probably are, provided it has not been started. Until the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank simply sits there and does nothing. Which makes the honest reply to the first Upper Lochton query — "have I wrecked it?" — usually no. Leave the motor off then call Petrol in Diesel — that is how you keep it like that. What petrol actually does to a diesel, how to gauge how far it's gone, and how to stop it from happening a second time: that is the remainder of this page.
Inside the motor: what petrol in a diesel does
Diesel does two tasks on its way through an engine. It combusts, and before it combusts it lubricates. What keeps the surfaces inside the high-pressure fuel pump and your injectors from grinding against one another is your diesel flowing through them — they're built to very fine tolerances.
Of those two jobs, petrol manages the first badly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is thinner than diesel and takes away the protection the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the knocking comes.
The shape of the trouble is plain when you put those together. Contact does not do the damage — movement does. Petrol in the tank is a fuel problem. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Upper Lochton, petrol in a diesel: four cases, from mild to serious
The best case there can be: filled up, never started. Being at a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With the petrol held inside your tank alone, it's cleared and cleaned on the spot, and nothing more is needed.
Started for a moment, or only the ignition on. With the system primed, the fuel lines and filter now hold petrol that came from the tank. Drain, flush, deal with the fuel filter: still normally simple.
Those few miles driven were the pump running on fuel diluted by petrol throughout. Tank, lines, filter, then fresh fuel run through the entire system: that's this work, and the way the car was driven matters as much as the mileage. Short trips, like the school run to the local primary school, are one thing. Driving as far as Aberdeen, under 25 miles away, makes a very different job — as does any mileage on the M90, over 50 miles from Upper Lochton, with the engine working hard all the way.
Driven till it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the motor is saying so. Pull up wherever you are — the verge on Upper Lochton East, a lay-by, a side street — and leave the vehicle where it is. A vehicle stopped soon very rarely has permanent damage, since the drain and the flush-through, which still go first, take care of it.
Upper Lochton motorists and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system copes with petrol, however much that guidance supposes.
If anything, the opposite holds. Myth: "A current diesel can cope with a bit of petrol." A newer diesel sends its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
One myth that catches people out: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel normally has no choice but to stop, because it will not run, and the harm stops there. While the pump wears, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. A running engine does not mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a distinct issue. That petrol is still inside that tank after that, and what it has weakened isn't put back.
If the engine has been run, part of the petrol sits in the filter and the fuel lines, not that tank — and the next start sends it straight back through the pump. So the myth "drain that tank yourself and you are sorted" doesn't hold. It's also truly dangerous to drain petrol into a can at the kerbside.
How it happens: petrol in a diesel
Nobody does it on purpose, and it is rarely carelessness. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol motor at all. So the mistake runs one way.
When routine and your car stop matching, it takes place. Hire cars, courtesy cars, and cars that are new to you. Two vehicles on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Fuelling up in a rush on the way to the nearest station, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. With rain, a call arriving, or children to deal with, the hand just does what it has always done.
Upper Lochton people: how to prevent petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of cars print the fuel there.
- One of each in the home? Mark the key to your diesel — a bright fob, a sticker — because meaning to remember isn't enough.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" out loud. Daft, yes, yet it works.
- Put the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices exist for cars without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- Less petrol means a weaker blend, and so stop as soon as you realise — while remembering that the next stage is unchanged. It is still not to fire it up.
Put petrol in a diesel around Upper Lochton already?
Short and simple, then, is the order of things. Do not start it, and don't switch the ignition on. Ask the attendants to help you roll it away from the petrol pump if you are still on the forecourt, whether that's Morrisons or somewhere else. Next, 0333 366 0103. We will ask what got in, about how much, and if it's been run.
Corrosion and deposits are the problem with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and read its own Upper Lochton page.
What makes one Upper Lochton petrol in a diesel task cost more than the next
The four situations above are four different tasks, so no single price for this would be honest. Which of them you are in is chiefly what shifts the cost. Where the car is counts too, and whether a van can safely reach it, after the proportion of petrol to what that tank takes.
That's why our engineers ask three queries before pricing rather than after: what went in, how much, and whether it has run. The answers turn a range into a straight figure.
About Upper Lochton itself
Upper Lochton is a suburban area in Aberdeenshire, situated inland at an elevation of 86 metres, approximately 16 miles west of Aberdeen. Upper Lochton lies near the settlements of Lochton of Leys and Banchory, and is characterized by its predominantly detached housing stock. Upper Lochton is a relatively small community, with a population of around 780 residents, and is part of the wider Aberdeen urban fringe.
Fuel drain cover in Upper Lochton and across Aberdeenshire
Upper Lochton rests in the AB postcode area, and the teams that answer petrol in diesel calls there work the spots near it as well — Lochton of Leys, Hill of Banchory and Banchory among them. We drain where your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Upper Lochton and still at the petrol pump?
Nothing beats it: that's where you now are. Phone, and leave it switched off.