How Worried Should You Be? Petrol in a Diesel Car in Herne
Likely less than you are now — as long as no one has started the vehicle. "Have I wrecked it?" is the first question everyone in Herne asks, and the truthful answer is usually no, since petrol left in a diesel tank hurts nothing until it's dragged through the system — by ignition priming, by your starter, or by driving. Keep it that way: leave your engine off then call Petrol in Diesel. What petrol actually does to a diesel, how to gauge how far it has gone, 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 does
Diesel does two tasks on its way through an engine. It burns, and before it burns it lubricates. What stops the surfaces inside the high-pressure pump and your injectors from wearing against one another is your diesel passing through them — they're designed to extremely fine clearances.
The second job petrol does not do at all, and the first it does badly. A pump working on a petrol blend is wearing itself out, since petrol is runnier than diesel and takes away the protection your fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where the clattering comes.
The shape of the trouble is plain once you put those together. Contact does not do the damage — movement does. Where that petrol is only inside the tank, it is a problem of fuel, nothing more. After your pump has been working on that petrol, a mechanical problem has begun: anything shed by a pump that is grinding travels onward to the fuel injectors with the fuel.
Petrol in a diesel in Herne: how serious is it? Four situations
Filled up, and not started: no case is better. The petrol is in your tank and only that tank, and the job is a drain and a flush where your car stands. This is the one situation that can only truly take place on a forecourt, since anywhere else the car has been driven to get there.
Started for a second, or just the ignition on. With the fuel system primed, the fuel lines and filter now hold petrol that came from your tank. That is generally still an easy task — a drain, a flush, and your filter dealt with.
The pump now spent a few miles on weakened fuel — that's what driving it meant. Tank, lines, filter, then fresh fuel run through the entire system: that is the work, and the way your car was driven counts as much as the miles. Driving the kids to Herne Church of England Junior School is one kind of trip. Very different a second time: a trip to Canterbury, under 10 miles away, or any miles on the M2, under 10 miles from Herne, where the engine never stopped running hard.
Driven till it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is the engine reporting fuel that no longer acts like diesel. Pull up wherever you are — the verge on School Lane, a lay-by, a side street — then leave the car there. The fuel drain and flush still come first, and they take care of it: if a vehicle is stopped quickly, permanent damage is very rare.
Myths Herne drivers hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that guidance presumes.
Not so: a modern diesel copes with a bit of petrol. If anything, the reverse. At higher pressure, through finer parts: that's how a current diesel handles its fuel, and so the lubrication counts more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up most people than any other. The motorist of a petrol motor fed diesel normally stops, because it will not run, and the damage stops there. Feed petrol to a diesel and it generally fires up, ticks over and drives away like nothing has happened — all while its pump wears. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate fault. The petrol is still in your tank after that, and what it has weakened is not put back.
The next start draws petrol back round the pump from the fuel lines and the fuel filter, where some of it ends up after your engine has run. That is why draining the tank yourself doesn't sort it — a myth. It's also genuinely risky to drain petrol into a can by the kerbside.
Petrol in a diesel: how does it happen?
A careless moment is seldom the cause, and no one means to do it. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it simple, and the slip runs one way.
The moment habit stops matching the vehicle is the moment it occurs. Hire cars, courtesy cars, and motors that are new to you. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Filling up in a rush on the way to Herne Bay, with a train to catch. Years of petrol motors behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up in Herne: avoiding petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Check the petrol pump's label; the colour is only a hint.
- Check your filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in any motor you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, in a household with one of each.
- "Diesel", aloud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- As soon as you notice, stop: less petrol in that tank means a thinner mix. What to do next does not change, though — still do not fire it up.
Put petrol in a diesel around Herne already?
Then, there's only a short order of things. Don't fire it up, and do not switch your ignition on. Ask the staff to help you roll it away from the pump if you are still on the forecourt, whether that's Sainsbury's or somewhere else. Then ring 0333 366 0103 and tell us what went in, about how much, and whether it has run.
Say so if it was AdBlue instead of petrol: it's a different issue, with its own page for Herne, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task around Herne costs more than another
The four situations above are four separate jobs, so no single price for this would be fair. The scenario itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a share of what that tank takes, then the spot your car is in and whether a technician can get to it safely.
Three queries come first, before quoting, rather than after — what was put in, how much, has it run — and this is the reason. A range turns into a straight figure once the replies are in.
About Herne
Herne is a village in Kent, situated near the coast and approximately 5 miles from Canterbury. Herne has a population of around 2054 people and is characterized by semi-detached housing. Herne sits at an elevation of 25 metres, close to nearby places such as Lower Herne and Herne Common. Herne is also within commuting distance to London, being around 55 miles away.
Across Kent and around Herne: fuel drain cover
Petrol in diesel call-outs around Herne — part of the CT postcode area — go to teams that also cover the spots about it, Lower Herne, Herne Common and Hunters Forstal among them. You need not move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Still at the pump in Herne?
Then you're in the best position there can be. Switched off it stays; then ring.