Pye Nest: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, provided it has not been started. Everyone in Pye Nest starts with "have I ruined it?", and the fair answer is generally no: petrol resting in your tank of a diesel stays harmless till priming, cranking or driving draws it into the fuel system. Keep it like that: leave the engine off and phone Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it's travelled, and how to stop it from happening a second time: that's the remainder of this page.
Petrol in a diesel: what does it do to your engine?
Passing through a motor, diesel is doing two things at once. Before it ignites, it protects — then it combusts. Your high-pressure pump and your injectors are made to very fine clearances, and the diesel passing through them is what stops those surfaces from wearing down against one another.
The second task petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump on the blend to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the rattling.
The shape of the trouble is plain once you put those together. Not contact but circulation is what does the damage. Petrol in the tank is a fuel problem. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors downstream.
How bad is petrol in a diesel? Four scenarios we see around Pye Nest
Filled but never started — as good as it gets. The petrol is in the tank and just the tank, and the task is a drain and a flush where the vehicle stands. This is the one scenario that can only truly happen on a forecourt, because anywhere else your car has been driven to get there.
A brief spell of running, or merely your ignition on. Petrol has left the tank and reached the fuel filter and the lines, because the fuel system has been primed. That's usually still a simple job — a drain, a flush, and your filter seen to.
Driven a few miles. Now your pump has spent those miles working on diluted fuel. Tank, lines, filter, then clean fuel put through the whole circuit: that's this work, and the way the vehicle was driven counts as much as the distance. Short trips, such as the school run to Warley Road Primary Academy, are one thing. Any mileage on the M62, under 5 miles from Pye Nest, means the motor working hard throughout, and a run to Bradford, under 10 miles away, is a very different job as well.
Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the motor signalling fuel that no longer behaves like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Copley Avenue. A vehicle pulled over early very seldom has lasting damage, as the fuel drain and the flush, which still go first, deal with it.
Myths Pye Nest motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed when you top up — your tank just holds more of the same blend. Percentage is not how a diesel fuel system copes with petrol, however much that guidance assumes.
Myth: a newer diesel copes with a bit of petrol. Rather, the reverse. Protection counts more on current diesels, not less, since their fuel passes through finer parts at higher pressure.
Myth: "If it starts and drives, there's no damage done." This is the one that catches people. Feed diesel to a petrol motor and it usually won't run, and so the motorist stops — and the damage stops with them. While the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running is not the same as fine.
An outdated fix for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It doesn't put back what petrol has thinned, and that petrol is still in the tank later on.
Myth: "Drain your tank yourself and you're sorted." After the motor has run, some of that petrol is no longer in your tank: it is in your filter and the lines, and it goes right back through your pump at your next start. Emptying petrol into a can at the roadside is also truly dangerous.
Why petrol in a diesel occurs so easily
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol car at all. So the error runs one way.
When habit and your car stop matching, it takes place. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. Fuelling up in a hurry en route to Sowerby Bridge, with a train to catch. The first fill-up in a diesel Renault Clio after years of driving petrol is precisely the moment it happens. Add a back seat full of kids, a phone call or rain, and habit wins.
Preventing petrol in a diesel next time you fill up around Pye Nest
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is just a hint.
- Check your filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on your first fill in a vehicle you don't know.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It sounds silly and it works.
- Tuck your phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels have a filler built to reject a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- Less petrol means a weaker mix, and so stop as soon as you realise — though remembering that the next step is unchanged. It's still not to crank it.
Already put petrol in a diesel around Pye Nest?
Then the order of things is short. Starting it is out, and so is switching on your ignition. Yet on the forecourt, at Asda or anywhere else? Ask the attendants to help you roll it clear of the petrol pump. What was put in, roughly how much, and whether it's run: tell us those when you ring 0333 366 0103.
If it was AdBlue rather than petrol, say so. That's a different issue — corrosion and deposits instead of lost lubrication — and it has its own page for Pye Nest.
One petrol in a diesel job around Pye Nest costs more than another. Why?
There is no fair single price for this, since the four scenarios above are four separate tasks. What moves your cost is mostly which of them you're in. Next it is the ratio — how much petrol was put in against how much your tank takes — and then where your car is and whether a van can get to it safely.
Before any quote, not after, come three queries: the fuel that went in, the amount, and if it's run. That is why. A range turns into a straight figure when the replies are in.
About Pye Nest itself
Pye Nest is a suburban area situated on the riverside in West Yorkshire, with an elevation of 147 metres. Pye Nest lies approximately 7.7 miles from Bradford and is surrounded by nearby places such as King Cross, Savile Park, and Willow Field. Pye Nest has a population of around 6067 people and is predominantly composed of terraced housing. Pye Nest is located 169.3 miles from London, in the Yorkshire and the Humber region.
Pye Nest and West Yorkshire: where our fuel drain cover reaches
King Cross, Savile Park and Willow Field are among the spots near Pye Nest that the same teams work, answering petrol in diesel jobs across Pye Nest's HX postcode area. No need to bring the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations we drain.
Still at the pump around Pye Nest?
Then you're in the best place there is. Keep it off. Phone.