Petrol in a Diesel Car in Farnborough Park: How Worried Should You Be?
Far less than you likely are, provided it hasn't been started. Everyone around Farnborough Park begins with "have I ruined it?", and the fair answer is normally no: petrol resting in that tank of a diesel remains harmless till priming, cranking or driving draws it into the fuel system. Petrol in Diesel is who to phone, with your motor kept off, and so it remains that way. What petrol actually does to a diesel, how to gauge how far it has gone, and how to stop it from happening a second time: that's the rest of this page.
The motor and petrol in a diesel: what goes on
Diesel has two tasks on its way through an engine. It protects to begin with, and after that does it burn. Very fine clearances are built into your injectors and the high-pressure fuel pump, and only your diesel flowing through stops their surfaces grinding together.
Petrol handles the first task poorly and the second not at all. It's thinner than diesel and strips away the lubrication your fuel system rests on, so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the knocking comes from.
Combined, those make the shape of the problem clear. It is movement that does the damage, not contact. Petrol in the tank is a fuel problem. After your pump has been labouring on that petrol, a mechanical issue has begun: anything shed by a pump that is grinding travels downstream to your injectors with your fuel.
Farnborough Park, petrol in a diesel: four situations, from mild to serious
Fuelled but not once started — the best it gets. Only your tank has petrol in it, and so the job is emptying that tank and cleaning your system where the vehicle stands. This scenario can only really take place on a forecourt: anywhere else, your car got there by being driven.
Started for a second, or just your ignition on. With the fuel system primed, the fuel lines and filter already contain petrol that has come from the tank. Normally nothing more than clearing, purging and seeing to the filter, so still simple.
A few miles driven, and your pump has spent each of them labouring on thinned fuel. How hard the vehicle was driven counts as much as how far, and this work takes in that tank, the lines, your filter and fresh fuel through the whole circuit. On the school run to St Patrick's Catholic Primary School, the miles is small. Driving as far as Winchester, under 50 miles away, makes a very different job — as does any distance on the M3, under 3 miles from Farnborough Park, with the engine labouring hard the whole time.
Driven on till it protested — rattling, smoke, a ragged idle, a soft throttle. What you are hearing is your engine reporting fuel that no longer runs like diesel. Stop wherever you are — the verge on Rectory Road, a lay-by, a side street — then leave the car where it is. What comes first is still the fuel drain and flush, and that deals with it, with long-term damage very rare when a vehicle is pulled over soon.
Farnborough Park drivers and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A fuller tank of the same mix is all you get, because topping up takes out nothing. Percentage isn't how a diesel fuel system tolerates petrol, however much that advice supposes.
If anything, the opposite is true. Myth: "A current diesel can cope with a bit of petrol." More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection count more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that catches drivers. Diesel in a petrol motor generally leaves a motor that will not run: the driver stops, and so does the damage. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, while the pump wears. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct problem. What petrol has thinned stays weakened, and the petrol stays in the tank regardless.
Myth: "Drain the tank yourself and you are sorted." Once your engine has been run, some of that petrol is no longer in the tank: it's in the filter and the fuel lines, and it goes straight back through the pump on the next start. Also, a can of petrol drained at the roadside is truly dangerous.
How does petrol in a diesel occur?
Carelessness is seldom the cause, and no one means to do it. A diesel nozzle generally won't go into a petrol vehicle, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and only in one direction.
Routine and the car falling out of step is when it takes place. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill en route to Farnborough Main. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: precisely when it occurs. Throw in a back seat full of kids, a phone call or rain, and habit wins.
Farnborough Park people: how to prevent petrol in a diesel next time
- The label is what matters, and so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on each forecourt.
- Inspect your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in a motor you don't know.
- Mark your key. In a house 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", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems silly. It does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop reading the pump.
- Stop the moment you realise. Less petrol in your tank makes a thinner mix. It doesn't change what to do next, which is still not to start it.
Farnborough Park: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't crank it, and do not turn the ignition on. Ask the staff to help you roll it clear of the pump if you're still at the forecourt, whether that is JET or somewhere else. Then call 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and see its own Farnborough Park page.
Why one petrol in a diesel task in Farnborough Park costs more than another
The four situations above are four different jobs, so no single price for this would be honest. What shifts the cost is chiefly which of them you are in. After that it is the proportion — how much petrol went in against how much that tank takes — and then where the car is and whether a technician can get to it safely.
What went in, how much, and if it has run — three questions we ask before quoting, not after, for precisely that reason. Those answers are what change a range into one firm number.
About Farnborough Park itself
Farnborough Park is a suburban area situated on the riverside in Hampshire, with an elevation of around 79 metres. Farnborough Park lies approximately 30 miles from London and is close to the city of Winchester, which is about 29 miles away. Farnborough Park is characterised by its predominantly detached housing stock, reflecting its residential nature. Farnborough Park is part of a larger area that includes nearby Farnborough Street, Farnborough, and South Farnborough.
Farnborough Park and Hampshire: where our fuel drain cover runs
Farnborough Street, Farnborough and South Farnborough are among the places around Farnborough Park that the same teams work, answering petrol in diesel call-outs across Farnborough Park's GU postcode area. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots we drain.
In Farnborough Park and still at the petrol pump?
No position is better: that is where you now are. Switched off it remains; then ring.