Petrol in a Diesel Car in Penrhyn-coch: How Worried Should You Be?
Not started? Then less anxious than you probably are. Till your ignition primes the pump, your starter cranks, or the vehicle is driven, petrol in a diesel tank just rests there and does no harm. Which means the honest reply to the first Penrhyn-coch query — "have I wrecked it?" — normally no. Leave the motor off then ring Petrol in Diesel — that is how you keep it that way. The remainder of this page explains what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
Your engine and petrol in a diesel: what happens
Diesel has two jobs on its way through a motor. It protects first, and only then does it burn. The high-pressure fuel pump and the injectors are made to very fine clearances, and your diesel passing through them is what stops those surfaces from grinding against each other.
Poorly at the first, not at all at the second: that is petrol. It's runnier than diesel and removes the lubrication the fuel system hinges on, so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the knocking comes from.
Combined, those make the shape of the problem clear. Not contact but movement is what does the damage. All a tank with petrol in it amounts to is a fuel problem. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
Petrol in a diesel in Penrhyn-coch: how serious is it? Four situations
Filled up, and never started: no case is better. That petrol is inside the tank and only that tank, and the task is a drain and a flush where the vehicle sits. This is the one scenario that can only truly take place at a forecourt, since anywhere else your car has been driven to get there.
A brief spell of running, or merely your ignition on. The system has been primed, so petrol has left the tank and got to the filter and the fuel lines. Still usually simple: drain, flush, and your filter sorted.
Some miles driven, and your pump has spent each of them working on diluted fuel. Mileage is only half of that; how hard it was driven counts equally. Either way the work includes the tank, the lines, the filter and fresh fuel through the whole system. Short trips, like the school run to the local primary school, are one matter. A run as far as Bangor, over 50 miles away, is a very different task. So is any miles on the M4, under 50 miles from Penrhyn-coch, where your engine has been working hard the whole time.
Driven on till it protested — rattling, smoke, an uneven idle, a soft throttle. The fuel isn't acting like diesel any more, and your engine is saying so. Stop where you are — on the verge on Maesheulog, at the kerb, down a side road — and don't move it again. Lasting damage is very uncommon if a vehicle is stopped soon, and the fuel drain and flush that still go first take care of it.
Penrhyn-coch motorists and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A fuller tank of the same mix is all you get, since topping up removes nothing. A diesel fuel system does not accept petrol by percentage in the way that advice supposes.
If anything, the opposite is true. Myth: "A modern diesel can cope with a bit of petrol." A modern diesel sends its fuel through more precise components at higher pressure, which makes the protection count more, not less.
"It starts, it drives, so no harm done" — the myth that trips up more motorists than any other. The motorist of a petrol motor fed diesel normally stops, since it will not run, and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump grinds. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old fix for a different problem. None of what petrol weakened gets put back by it — and afterwards, your tank still holds the petrol.
If the engine has been run, part of the petrol is in the fuel filter and the lines, not your tank — and your next start pulls it right back through the pump. So the myth "drain that tank yourself and you are sorted" doesn't hold. Clearing petrol into a can by the roadside is also really risky.
How it happens: petrol in a diesel
A careless moment is rarely the cause, and no one means to do it. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol motor. That's how the forecourt makes it easy.
The moment habit stops matching the car is the moment it takes place. Courtesy car, hire car, or a motor that's brand new. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps now in a different order. A train to catch, and a rushed fill on the way to Bow Street. Years of petrol motors behind you, a diesel Peugeot 308 in front of you at the forecourt for its first tank — that's when. Throw in a back seat full of kids, a phone call or rain, and the hand takes over.
Penrhyn-coch 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, even if most usually do. Check the pump's label; the colour is only a clue.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors print the fuel there.
- 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.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car needs its first tank. It sounds silly. It does the trick.
- Mistakes like this are easy to make while your mind is on something else, and so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and add-on devices exist for the rest. Treat it as a backstop, and keep checking the petrol pump.
- As soon as you realise, stop: less petrol in your tank means a thinner mix. What to do next doesn't change, though — still do not crank it.
Already put petrol in a diesel around Penrhyn-coch?
The order of things is short, then. Do not turn the ignition on, and don't start it. If you're still on the forecourt — BP or anywhere else — ask the staff to help you roll the vehicle clear of the pump. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it's been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate problem — Penrhyn-coch has a page just for it.
One petrol in a diesel job in Penrhyn-coch costs more than another. Why?
A fair single quote does not exist here: four situations, four separate tasks. What moves your cost is chiefly which of them you're in. Next it is the share — how much petrol went in against how much the tank takes — and after that where the vehicle is and whether a technician can reach it safely.
Three questions come first, before any quote, instead of after — what got in, how much, has it run — and that is the reason. A range becomes a straight figure when those replies are in.
About Penrhyn-coch and its setting
Penrhyn-coch is a village in Ceredigion, situated on the banks of a river at an elevation of 48 metres. Penrhyn-coch lies near the settlements of Garth and Plas Gogerddan, and is part of a wider area that includes Cefn Llwyd. Penrhyn-coch has a population of around 938 people, predominantly living in semi-detached housing. Penrhyn-coch is located approximately 176.8 miles from London and 54.9 miles from Bangor.
Fuel drain cover across Ceredigion, Penrhyn-coch included
Penrhyn-coch rests in the SY postcode area, and our teams that answer petrol in diesel jobs there work the places around it as well — Garth, Plas Gogerddan and Cefn Llwyd among them. We drain where your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the pump around Penrhyn-coch?
Nothing beats it: that's where you now are. Call, and leave it turned off.