How Worried Should You Be? Petrol in a Diesel Car in Higher Audley
Provided it hasn't been started, worry less than you probably are. Petrol resting in a diesel tank does nothing to your motor until something draws it through the system — the ignition priming your pump, the starter, or driving itself. So the fair answer to the first query everyone in Higher Audley asks, "have I wrecked it?", is normally no. Petrol in Diesel is who to call, with your engine kept off, and so it stays that way. What petrol really does to a diesel, how to gauge how far it has travelled, and how to stop it from happening again: that is the remainder of this page.
What petrol in a diesel does to your engine
Two tasks fall to diesel on its journey round a motor. It lubricates to begin with, and after that does it burn. Very fine tolerances are built into the injectors and your high-pressure pump, and only the diesel running through keeps those surfaces from grinding together.
The second job petrol doesn't do at all, and the first it does badly. A pump working on a petrol mixture is wearing itself out, because petrol is runnier than diesel and takes away the protection your 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 starts.
Seen together, they show what shape the problem has. Not contact but movement is what causes the harm. Petrol in the tank is a fuel problem. Whatever a worn pump sheds goes on, borne by your fuel, into your injectors downstream, which is why a pump that has been working on the petrol is where a mechanical issue starts.
How serious is petrol in a diesel? Four situations our engineers see around Higher Audley
Fuelled, and not started: nothing beats it. Just your tank has petrol in it, and so the task is emptying that tank and purging the system where your car stands. This scenario can only truly occur at a forecourt: anywhere else, the vehicle got there by being driven.
A moment's running, or merely the ignition on. With your system primed, your lines and filter already contain petrol that has come from that tank. That's normally still a simple job — a drain, a flush, and the fuel filter dealt with.
Your pump has worked a couple of miles on weakened fuel — that's what driving the car meant. How hard the car was driven matters as much as how far, and the work covers the tank, the lines, your filter and clean fuel through the entire circuit. Short trips, such as the school run to Audley Infant School, are one thing. Getting as far as Preston, under 10 miles away, makes a very different task — as does any miles on the M65, under 3 miles from Higher Audley, with the motor running hard the whole time.
Driven till it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is your motor signalling fuel that no longer behaves like diesel. Pull up on the spot — on the verge on Walter Street, at the kerb, down a side road — and don't move it again. The drain and flush still go first, and they sort it out: if a vehicle is stopped quickly, permanent damage is very unusual.
Petrol in a diesel myths Higher Audley drivers hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing comes out when you top up — the tank just holds more of the same mixture. That guidance presumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: a modern diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through finer components: that's how a current diesel moves its fuel, so the lubrication matters more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more motorists than any other. Diesel in a petrol motor normally leaves a motor that will not run: the motorist stops, and so does the harm. Feed petrol to a diesel and it normally starts, idles and pulls away like nothing has happened — all while its pump is wearing. Fine and running are not the same thing.
An outdated fix for a distinct fault is behind this one. Myth: "Add some two-stroke oil and drive it home." That petrol is still in the tank after that, and what it has diluted is not put back.
The next start sends petrol back round your pump from the fuel lines and your filter, where some of that sits once the engine has run. That's why draining your tank yourself does not sort it — a myth. Draining petrol into a can by the kerbside is also genuinely risky.
Why petrol in a diesel occurs so easily
On purpose? Never. Through carelessness? Seldom, if ever. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol motor. That is how the forecourt makes it easy.
It occurs when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. Two vehicles on one drive, one petrol, one diesel. A well-known forecourt with the pumps in a different order. Filling up in a hurry on the way to Blackburn, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. The hand does what it has always done when you add rain, a phone call or a back seat full of children.
Higher Audley people: how to avoid petrol in a diesel next time
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: many vehicles print the fuel type there.
- Label your key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- "Diesel", out loud, before you lift the nozzle — each time a new or hired car gets its first tank. It sounds daft. It does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, so the phone goes away.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Stop as soon as you realise. Less petrol in that tank means a weaker mix. It doesn't change what to do next, which is still not to crank it.
Higher Audley: already put petrol in a diesel?
In that case, there's only a short order of things. Don't fire it up, and do not switch the ignition on. The staff on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it clear of the petrol pump if you ask. What got in, about how much, and whether it has run: tell us that when you ring 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Higher Audley has a page just for it.
One petrol in a diesel task around Higher Audley costs more than another. Why?
Four different tasks lie behind the four scenarios above — which is why there is no fair single quote. Which of them you are in is mostly what moves your cost. Two things follow that: the petrol that went in as a share of what your tank takes, then the place your car is in and whether a technician can reach it safely.
What was put in, how much, and whether it has run — three questions we ask before pricing, not after, for precisely that reason. A range becomes a straight figure once the replies are in.
About Higher Audley itself
Higher Audley is a suburban area in Lancashire, situated near the River Ribble and characterised by its terraced housing stock. Higher Audley sits at an elevation of 137 metres, approximately 9.5 miles south west of Preston, and forms part of the wider Preston urban area. Higher Audley is close to several other local suburbs, including Queens Park and Lower Audley.
Higher Audley and Lancashire: where our fuel drain cover reaches
Higher Audley rests in the BB postcode area, and our teams that answer petrol in diesel calls there work the spots around it as well — Queens Park, Park Place and Lower Audley among them. The vehicle doesn't need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump around Higher Audley?
Nothing beats it: that is where you now are. Ring, and keep it switched off.