How Worried Should You Be? Petrol in a Diesel Car in Marywell
Far less than you likely are, provided it hasn't been started. "Have I wrecked it?" is the first question anyone around Marywell asks, and the honest answer is usually no, because petrol left in a diesel tank hurts nothing till it's dragged through your fuel system — by ignition priming, by your starter, or by driving. To keep the vehicle like that, ring Petrol in Diesel then leave the motor alone. What petrol really does to a diesel, how to gauge how far it has gone, and how to keep it from happening a second time: that is the remainder of this page.
The motor and petrol in a diesel: what goes on
Diesel has two jobs on its way through a motor. Before it ignites, it lubricates — then it ignites. Your high-pressure pump and your injectors are built to extremely fine tolerances, and your diesel passing through them is what stops those surfaces from grinding against each other.
Of these two tasks, petrol manages the first badly and the second never. The clattering comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication the system rests on, and any pump working on such a blend is wearing itself.
Together, those leave the shape of the issue clear. It is circulation that does the harm, not contact. Where the petrol is only in your tank, it's a fault of fuel, nothing more. Once your pump has been working on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing is carried downstream to the injectors with the fuel.
Four situations our engineers see in Marywell: how bad is petrol in a diesel?
Fuelled but not once started — as good as it gets. On a forecourt, and really only there, the petrol is still confined to that tank — because everywhere else your car was driven to get to it. The task is emptying and cleaning on the spot.
Started for a moment, or just your ignition on. With the fuel system primed, the fuel lines and filter now contain petrol that has come from the tank. That is usually still a straightforward job — a drain, a flush, and the filter dealt with.
Some miles driven, and your pump has spent each of them labouring on thinned fuel. The work is your tank, your lines, the filter and fresh fuel through the whole system, and how hard the car was driven counts as much as how far. Driving the children to the local primary school is one kind of trip. Any mileage on the M90, over 50 miles from Marywell, means the motor working hard throughout, and a run to Aberdeen, under 5 miles away, makes a very different task as well.
Knocking, an uneven idle, smoke, a throttle gone soft: driven until it complained. The fuel isn't behaving like diesel any more, and the motor is telling you. Stop where you are — on the verge on Checkbar, at the kerb, down a side road — and do not move it again. The fuel drain and flush-through still come first, and they take care of it: when a car is pulled over early, long-term damage is very rare.
Myths Marywell people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. Topping up takes out nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, whatever that advice assumes.
Myth: a current diesel copes with a bit of petrol. Rather, the reverse. A modern diesel sends its fuel through smaller parts at higher pressure, which makes the lubrication matter more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up more motorists than any other. Feed diesel to a petrol motor and it normally will not run, and so the driver stops — and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile your pump grinds. Fine and running are not the same at all.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different fault. The petrol is still inside that tank afterwards, and whatever it has weakened isn't put back.
If your engine has run, part of the petrol sits in your filter and the fuel lines, not the tank — and the next start pulls it straight back through the pump. So the myth "drain that tank yourself and you are sorted" doesn't hold. On top of that, petrol emptied into a can by the road is genuinely hazardous.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and no one does it on purpose. 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 motor at all. The forecourt makes it simple, and the error runs one way.
When routine and the vehicle stop matching, it happens. A new vehicle, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. A forecourt you know, but with its pumps arranged differently. A train to catch, and a hurried fill on the way to Portlethen. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: exactly when it occurs. Throw in a back seat full of kids, a phone call or rain, and habit takes over.
Avoiding petrol in a diesel next time you fill up around Marywell
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is just a hint.
- Check your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any car you don't know.
- Mark the key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- It sounds silly and it works: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Whilst 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 have a filler designed to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a safety net, not a reason to stop checking the pump.
- Less petrol means a weaker mix, so stop the moment you realise — while remembering that your next stage is unchanged. It's still not to start the vehicle.
Put petrol in a diesel around Marywell already?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. The attendants at the forecourt — whether at EG On the Move itself or wherever you filled up — will normally help roll it clear of the petrol pump if you ask. Then ring 0333 366 0103 and tell us what went in, roughly how much, and whether it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate issue — Marywell has a page all for it.
Marywell petrol in a diesel tasks: why one costs more than another
An honest single quote doesn't exist here: four situations, four separate tasks. Mostly, your cost shifts with which situation you are in. Next it is the ratio — how much petrol went in against how much that tank holds — and after that where your car is and whether a technician can get to it safely.
Before any quote, not after, come three queries: your fuel that went in, its amount, and if it's run. That's why. A range becomes a straight figure when those replies are in.
About Marywell itself
Marywell is a small coastal village in Aberdeenshire, situated near Aberdeen and overlooking the North Sea. Marywell sits at an elevation of 103 metres, with detached housing being the predominant type of accommodation in the area. Marywell is close to other nearby places such as Hillside, Charlestown, and Duffs Hill, and is approximately 393.5 miles from London.
Marywell and Aberdeenshire: where our fuel drain cover reaches
Petrol in diesel call-outs around Marywell — part of the AB postcode area — go to teams that likewise cover the locations round it, Hillside, Charlestown and Duffs Hill included. You need not move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Still at the pump around Marywell?
Nothing beats it: that is where you are. Turned off it remains; then ring.