How Worried Should You Be? Petrol in a Diesel Car in Inverallochy
If it has not been started, you can worry less than you likely are. "Have I wrecked it?" is the first question anyone in Inverallochy asks, and the truthful answer is generally no, since petrol resting in a diesel tank hurts nothing until it's dragged through your fuel system — by ignition priming, by the starter, or by being driven. To keep the car that way, call Petrol in Diesel and leave the engine switched off. What petrol actually does to a diesel, how to gauge how far it has gone, and how to keep it from happening again: that is the remainder of this page.
The engine and petrol in a diesel: what happens
Two tasks fall to diesel on its route round a motor. It protects first, and after that does it burn. What stops the surfaces inside the high-pressure fuel pump and the fuel injectors from wearing against one another is the diesel flowing through them — they're built to very fine gaps.
The second job petrol doesn't do at all, and the first it does poorly. The clattering comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication your system rests on, and any pump working on that mixture is wearing itself.
Taken together, they make clear what shape the problem has. Contact does not do the harm — movement does. Petrol in the tank is a fuel problem. Whatever a worn pump sheds travels on, carried by the fuel, into the fuel injectors further along, which is why a pump that has worked on that petrol is where a mechanical issue begins.
Petrol in a diesel around Inverallochy: how bad is it? Four situations
Filled up, and not started: nothing beats it. Being on a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol kept inside your tank alone, it is cleared and flushed on the spot, and nothing more is needed.
Ignition on, or started for a moment. With the fuel system primed, the fuel lines and filter now hold petrol that has come from your tank. Usually little more than clearing, cleaning and sorting the fuel filter, and so still straightforward.
Those few miles on the road were your pump labouring on fuel weakened by petrol the whole way. How hard your car was driven matters as much as how far, and this work takes in your tank, the lines, the filter and clean fuel through the entire system. Driving the kids to the local primary school is one sort of trip. Any distance on the M90, over 50 miles from Inverallochy, means the engine working hard throughout, and a run to Aberdeen, under 50 miles away, makes a very different job as well.
Driven on till it complained — knocking, smoke, an uneven idle, a soft throttle. That's your motor telling you its fuel no longer is acting like diesel. Pull up on the spot — on the verge on Rathen Road, at the kerb, down a side road — and do not move it. A vehicle pulled over early very rarely has long-term damage, as the drain and the flush-through, which still come first, deal with it.
What Inverallochy drivers get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. That guidance presumes a diesel fuel system handles petrol by percentage. It doesn't.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." Lubrication counts more on modern diesels, not less, because their fuel runs through smaller components at higher pressure.
This is the one that catches motorists. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol motor and it generally will not run, and so the motorist stops — and the damage stops with them. While your pump wears, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Being able to run is not the same as being fine.
An old fix for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol weakened is put back by it — and later, your tank still holds that petrol.
If your engine has run, part of that petrol is in the fuel filter and the fuel lines, not the tank — and the next start sends it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not stand up. Clearing petrol into a can by the kerbside is also genuinely dangerous.
Why petrol in a diesel happens at all
No one does it on purpose, and it is seldom carelessness. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides 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 the vehicle stop matching, it happens. Any motor that's new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. A forecourt you know, only with its pumps arranged differently. Racing for a train outside the nearest station and fuelling up en route. The first fill-up in a diesel BMW 3 Series after years of driving petrol is precisely the moment it takes place. With rain, a call coming in, or a car full of children to deal with, your hand simply does what it has always done.
Inverallochy motorists: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the pump's label; the colour is only a hint.
- The first fill in a strange car is the time to check your filler flap — inside it, or on the cap, many motors state which fuel to use.
- One of each in the home? Mark your key to the diesel — a bright fob, a sticker — since meaning to remember is not enough.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car needs its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for the rest. Count it as a safety net, then keep reading the petrol pump.
- Stop as soon as you notice. Less petrol in your tank makes a thinner blend. It doesn't change what to do next, which is still not to start the car.
Inverallochy: already put petrol in a diesel?
The order of things is short, then. Do not turn your ignition on, and do not start it. If you're still on the forecourt — the nearest petrol station or anywhere else — ask the staff to help you push the vehicle clear of the petrol pump. Next, 0333 366 0103. We'll ask what went in, about how much, and if it's been run.
Say so if it was AdBlue instead of petrol: it is a different problem, with its own page for Inverallochy, because AdBlue brings corrosion and deposits instead of lost lubrication.
One petrol in a diesel job in Inverallochy costs more than another. Why?
Four different tasks lie behind the four scenarios above — which is why there is no fair single quote. The situation itself does most of the work of moving your cost. After that it is the proportion — how much petrol was put in against how much your tank takes — and after that where your car is and whether a van can get to it safely.
What went in, how much, and if it has run — three questions our engineers ask before quoting, not after, for exactly that reason. Those replies are what change a range into one firm number.
About Inverallochy
Inverallochy is a small coastal village in Aberdeenshire, situated near the towns of Cairnbulg and St Combs. Inverallochy lies at a low elevation of around 9 metres, with its detached houses reflecting the local architectural style. Inverallochy is located approximately 36.8 miles north of Aberdeen, making it a rural community with a strong sense of identity.
Fuel drain cover across Aberdeenshire, Inverallochy included
Cairnbulg, Charleston and St Combs are among the places around Inverallochy that the same vans work, answering petrol in diesel calls across Inverallochy's AB postcode area. No need to move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Inverallochy: still at the pump?
The best position there is, then — that's where you are. Turned off it remains; then call.