Petrol in a Diesel Car in Hayfield: How Worried Should You Be?
If it hasn't been started, worry less than you likely are. Petrol sitting in a diesel tank does nothing to your engine until something draws it through your fuel system — the ignition priming your pump, the starter, or the drive itself. So the honest answer to the first query everyone in Hayfield asks, "have I wrecked it?", is generally no. Keep it like that: leave the engine off then ring Petrol in Diesel. The rest of this page covers what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
The engine and petrol in a diesel: what happens
On its way through an engine, diesel does two jobs. Before it burns, it lubricates — then it burns. Extremely fine gaps go into the injectors and your high-pressure pump, and only the diesel flowing through keeps their surfaces from grinding together.
Petrol does the first task badly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump running on the mixture wearing itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Taken together, they make clear the shape the issue has. The harm is done by circulation, not by contact. Any tank with petrol in it is a fuel problem. Once your pump has been working on that petrol, a mechanical issue has started: whatever is shed by a pump that is grinding is carried downstream to the injectors with your fuel.
How serious is petrol in a diesel? Four situations our technicians see around Hayfield
Fuelled up, never started. The best case there is. Just that tank has petrol in it, and so the job is clearing your tank and flushing the fuel system where your car sits. This situation can only really happen at a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a brief start. Petrol has come out of your tank and got to your filter and the fuel lines, because the fuel system has been primed. Normally little more than emptying, rinsing and sorting the filter, so still straightforward.
Driven a few miles. Now the pump has spent those miles running on weakened fuel. The work is that tank, the fuel lines, the fuel filter and fresh fuel through the entire system, and how hard the vehicle was driven counts as much as how far. The school run to the local primary school is one matter. Very different once more: a trip to Edinburgh, under 15 miles away, or any mileage on the M90, under 10 miles from Hayfield, where your engine kept labouring hard.
Driven until it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. That is your engine telling you its fuel has stopped acting like diesel. Pull up on the spot — on the verge on Wilson Avenue, at the kerb, down a side road — and do not move it again. A vehicle stopped soon very seldom has permanent damage, because the drain and the flush, which still go first, sort it out.
Myths Hayfield 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 — that tank simply carries more of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance assumes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. Smaller components and higher pressure are how a modern diesel runs its fuel, and that 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 usually has no choice but to stop, because it will not run, and the harm stops there. Whilst the pump wears, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. The petrol is still inside your tank afterwards, and what it has thinned isn't put back.
If the engine has run, part of the petrol sits in the fuel filter and your lines, not the tank — and your next start pulls it right back through your pump. So the myth "drain the tank yourself and you are sorted" doesn't stand up. Emptying petrol into a can at the roadside is also genuinely dangerous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
When habit and your car stop matching, it occurs. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a familiar forecourt. A hurried fill en route to Kirkcaldy with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: exactly when it occurs. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
How to avoid petrol in a diesel at your next fill-up around Hayfield
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Read the pump's label; the colour is only a clue.
- Plenty of motors state the fuel type inside the filler flap or on the cap, so check it on your first fill in a vehicle you don't know.
- One of each in the household? Label the key to your diesel — a bright fob, a sticker — since intending to remember isn't enough.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car gets its first tank. It sounds daft. It does the trick.
- Tuck the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for the remainder. Count it as a backstop, then keep checking the pump.
- Less petrol means a weaker blend, and so stop as soon as you notice — while remembering that your next stage is unchanged. It's still not to start it.
Petrol already in a diesel in Hayfield? Start here
Short and simple, then, is the order of things. Starting it is out, and so is turning on your ignition. Ask the staff to help you push it away from the pump if you are still on the forecourt, whether that is Shell or somewhere else. Phone 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and whether it's run.
Say so if it was AdBlue instead of petrol: it is a different fault, with its own page for Hayfield, because AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job in Hayfield costs more than another
There is no fair single quote for this, because the four scenarios above are four separate jobs. Which of them you are in is chiefly what moves the cost. Two things come after that: the petrol that got in as a share of what that tank takes, then the spot the vehicle is in and whether our van can get to it safely.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and this is the reason. The replies turn a range into a straight figure.
About Hayfield itself
Hayfield is a suburban area in Fife, situated near the coast and approximately 11.7 miles from Edinburgh. Hayfield has a relatively low elevation of 47 metres and is characterized by predominantly flat-type housing. Hayfield is part of the larger urban area surrounding Edinburgh, with nearby places including Smeaton, Templehall, and Dunnikier.
Fuel drain cover across Fife, Hayfield included
Petrol in diesel call-outs around Hayfield — part of the KY postcode area — go to teams that likewise cover the places round it, Smeaton, Templehall and Dunnikier among them. The car does not need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Hayfield and still at the petrol pump?
Then you're in the best place there is. Switched off it remains; then call.