Newton of Pitcairns: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, worry less than you probably are. Petrol sitting in a diesel tank does nothing to the engine till something draws it through the fuel system — the ignition priming your pump, the starter, or the drive itself. So the honest answer to the first query everyone around Newton of Pitcairns asks, "have I ruined it?", is usually no. Keep it that way: leave the motor off then ring Petrol in Diesel. What petrol really does to a diesel, how to judge how far it's travelled, and how to keep it from happening a second time: that's the remainder of this page.
Inside your engine: what petrol in a diesel really does
Two tasks fall to diesel on its journey round a motor. It ignites, and before it combusts it protects. Designed to extremely fine tolerances, your injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Petrol does the first task poorly and the second not at all. A pump working on a petrol blend is wearing itself out, because petrol is thinner than diesel and strips out the lubrication the fuel system depends on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where any knocking comes.
The shape of the problem is clear once you put those together. Contact doesn't do the damage — circulation does. All a tank with petrol in it amounts to is a fuel issue. After your pump has been running on that petrol, a mechanical fault has begun: anything shed by a pump that is wearing down travels downstream to the fuel injectors with the fuel.
Petrol in a diesel around Newton of Pitcairns: how serious is it? Four situations
Filled up, and not started: no case is better. Just the tank has petrol in it, so the task is draining your tank and cleaning the fuel system where the vehicle sits. This situation can only truly take place on a forecourt: anywhere else, the vehicle got there by being driven.
Started for a second, or just your ignition on. Petrol has come out of that tank and got to the filter and the fuel lines, since the system has been primed. Still generally easy: drain, flush, and the fuel filter seen to.
Those few miles driven meant your pump working on fuel thinned by petrol throughout. How hard the car was driven counts as much as how far, and the work takes in that tank, your lines, your filter and clean fuel through the entire circuit. A school run to the local primary school is one matter. A run as far as Perth, under 10 miles away, is a very different task. So is any mileage on the M90, under 10 miles from Newton of Pitcairns, where your engine has been running hard throughout.
Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. That is your engine telling you its fuel has stopped behaving like diesel. Pull up wherever you are — the verge on Newton of Pitcairns, a lay-by, a side street — and leave the car where it is. A car pulled over soon very rarely has long-term damage, since the drain and the flush-through, which still go first, sort it out.
Newton of Pitcairns drivers and the petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed when you top up — that tank just carries more of the same blend. Percentage isn't how a diesel fuel system tolerates petrol, whatever that guidance presumes.
"Current diesels can handle a little petrol" — a myth, and nearer the reverse. Finer parts and higher pressure are how a current diesel runs its fuel, and that makes the lubrication count more, not less.
One myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it generally will not run, and so the motorist stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Fine and running are not the same thing.
Myth: "Add some two-stroke oil and drive the car home." It is an old workaround for a different problem. None of what petrol weakened is put back by it — and afterwards, your tank still holds that petrol.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol lies in the filter and lines, waiting to go right back through your pump at your next start. Draining petrol into a can by the kerbside is also truly dangerous.
How petrol ends up: petrol in a diesel
No one does it on purpose, and it's rarely carelessness. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol motor at all. The forecourt makes it simple, and the error runs one way.
It happens when habit and your car stop matching. Any motor that is new to you — hired, on loan as a courtesy car, or brand new. One petrol and one diesel on the drive of the same household. The pumps in a different order on a familiar forecourt. Filling up in a rush on the way to Gleneagles, with a train to catch. A new-to-you diesel Renault Clio, its first fuelling, and a driver accustomed to petrol: precisely when it occurs. With rain, a call arriving, or a car full of children to deal with, your hand simply does what it has always done.
How to avoid petrol in a diesel at your next fill-up in Newton of Pitcairns
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what matters.
- The first fill in an unfamiliar car is the time to check your filler flap — inside it, or on the cap, plenty of motors state which fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a household has one of each. So mark it.
- Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, yes, yet it does the trick.
- Tuck the phone away. This is an easy mistake to make whilst you are 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. Helpful — but a backstop only, never a reason to stop checking the label.
- Spotting it mid-fill? Stop there and then. A weaker blend results from less petrol in the tank, yet the next stage remains the same: don't start the vehicle.
Petrol already in a diesel in Newton of Pitcairns? Begin here
Short and simple, then, is the order of things. Do not crank it, and don't turn your ignition on. Yet on the forecourt, at the nearest petrol station or anywhere else? Ask the attendants to help you roll it away from the pump. What went in, roughly how much, and if it's run: tell us those when you call 0333 366 0103.
If it was AdBlue and not petrol, say so. That's a different fault — corrosion and deposits instead of lost protection — and it has its own page for Newton of Pitcairns.
What makes one Newton of Pitcairns petrol in a diesel task cost more than the next
There is no honest single price for this, since the four situations above are four separate tasks. What moves your cost is mostly which of them you're in. Two things follow that: the petrol that went in as a proportion of what that tank holds, then the spot the vehicle is in and whether a technician can reach it safely.
That is why our engineers ask three queries before pricing instead of after: what went in, how much, and whether it has run. The answers turn a range into a straight figure.
About Newton of Pitcairns
Newton of Pitcairns is a suburban area situated on the riverside in Perth and Kinross, with a relatively low elevation of 70 metres. Newton of Pitcairns lies close to the city of Perth, approximately 8 miles away, and is near other small settlements such as Dunning and Duncrub. Newton of Pitcairns has a mix of housing types, but semi-detached homes are predominant in the area. Newton of Pitcairns is located about 360 miles north of London, in the Scottish countryside.
Newton of Pitcairns and Perth and Kinross: where our fuel drain cover reaches
Newton of Pitcairns rests in the PH postcode area, and the teams that answer petrol in diesel call-outs there work the locations near it as well — Dunning, Duncrub and Wester Keltie among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our technicians work, and your car doesn't need to come to us.
Newton of Pitcairns: still at the petrol pump?
Then, you couldn't be in a better place. Turned off it stays; then call.