Petrol in a Diesel Car in Stotfield: How Worried Should You Be?
Not started? Then less anxious than you likely are. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through the fuel system — the ignition priming the pump, the starter, or driving on its own. So the honest answer to the first question anyone around Stotfield asks, "have I wrecked it?", is generally no. Petrol in Diesel is who to ring, with the motor kept off, and so it remains that way. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and ways to make sure you never repeat it.
Petrol in a diesel: what does it do to your engine?
On its way through a motor, diesel has two tasks. It ignites, and before it combusts it lubricates. Made to very fine tolerances, your injectors and your pump rely on the diesel flowing through them to stop their surfaces wearing against one another.
Poorly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump running on that mixture to wear itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the knocking.
Taken together, they make clear the shape the trouble takes. Contact does not do the damage — circulation does. All a tank with petrol in it amounts to is a fuel problem. Once the pump has been working on that petrol, a mechanical problem has started: whatever is shed by a pump that is grinding travels downstream to your injectors with the fuel.
How serious is petrol in a diesel? Four scenarios our technicians see around Stotfield
Fuelled but not once started — the best it gets. Just the tank has petrol in it, and so the job is draining that tank and rinsing your system where the car stands. This situation can only truly take place on a forecourt: anywhere else, your car got there by being driven.
Started for a moment, or just the ignition on. The system has been bled, so petrol has left your tank and reached the filter and the lines. That is generally still a straightforward job — a drain, a flush, and the fuel filter dealt with.
A couple of miles driven, and your pump has spent every one of them working on diluted fuel. How hard the vehicle was driven counts as much as how far, and this work takes in the tank, the fuel lines, the fuel filter and clean fuel through the whole circuit. Short trips, like the school run to the local primary school, are one thing. A run as far as Inverness, under 50 miles away, is a very different job. So is any mileage on the M90, over 50 miles from Stotfield, where the engine has been labouring hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The fuel isn't acting like diesel any more, and the motor is saying so. Pull up on the spot — on the verge on Tulloch's Brae, at the kerb, down a side road — and do not move it again. The drain and flush still come first, and they sort it out: when a car is pulled over early, permanent damage is very uncommon.
Stories Stotfield people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing comes out when you top up — the tank just holds more of the same mixture. The assumption behind that guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." A modern diesel sends its fuel through finer components at higher pressure, which makes the protection matter more, not less.
One myth that catches people off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel normally stops, because it will not run, and the damage stops with them. A diesel fed petrol usually starts, idles and drives away as though nothing has happened, whilst the pump grinds. Running isn't the same as fine.
Not so: a two-stroke additive lets you to drive home. It is an old workaround, meant for another issue. None of what petrol diluted is put back by it — and later, the tank still contains the petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol sits in the fuel filter and lines, waiting to go right back through the pump at your next start. Emptying petrol into a can by the roadside is also truly hazardous.
How petrol ends up: petrol in a diesel
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it easy, and the slip runs one way.
When routine and your car stop matching, it occurs. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. A rushed fill on the way to Elgin with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. The hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
Stotfield motorists: how to prevent petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Check the petrol pump's label; the colour is just a hint.
- Many vehicles state the fuel type inside your filler flap or on the cap, and so check there on the first fill in any motor you don't know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, for a home with one of each.
- 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 pump.
- Mistakes like this are easy to make while your mind is on something else, and so the phone goes 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 motors without one. They are a safety net, not a reason to stop checking the petrol pump.
- Stop the moment you notice. Less petrol in the tank means a weaker blend. It doesn't change what to do next, which is still not to start it.
Stotfield: already put petrol in a diesel?
The order of things is brief, then. Leave it unstarted, with the ignition off as well. If you're still on the forecourt — the nearest petrol station or anywhere else — ask the staff to help you roll the vehicle away from the pump. Then phone 0333 366 0103 and tell us what got in, roughly how much, and if it has run.
Say so if it was AdBlue instead of petrol: it is a separate fault, with its own page for Stotfield, since AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Stotfield petrol in a diesel task cost more than the next
An honest single price doesn't exist here: four situations, four separate tasks. What moves your cost is mostly which of them you are in. Where the vehicle is matters too, and whether a van can safely reach it, after the proportion of petrol to what your tank holds.
Three queries come first, before any quote, rather than after — what went in, how much, has it run — and this is the reason. Those answers change a range into a straight figure.
About Stotfield, briefly
Stotfield is a coastal suburban area in Moray, situated near the towns of Lossiemouth and Branderburgh. Stotfield sits at a low elevation of 18 metres, looking out to the Moray Firth. Stotfield has a mix of housing types, with semi-detached homes being particularly prevalent in the area. Stotfield is located within commuting distance of Inverness, the nearest city, which is 38 miles away.
Across Moray and around Stotfield: fuel drain cover
Branderburgh, Lossiemouth and Seatown are among the places near Stotfield that the same teams work, answering petrol in diesel calls across Stotfield's IV postcode area. We drain wherever the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Stotfield: still at the pump?
In that case, you could not be in a better position. Switched off it remains; then ring.