Bickley: Petrol in a Diesel Car? How Worried to Be
Far less than you likely are, if it hasn't been started. Everyone around Bickley starts with "have I wrecked it?", and the honest answer is generally no: petrol resting inside your tank of any diesel remains harmless till priming, cranking or driving pulls it into the fuel system. To leave the vehicle like that, phone Petrol in Diesel and leave your engine switched off. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and the way to make sure you don't repeat it.
Inside the motor: what petrol in a diesel really does
On its way through a motor, diesel has two jobs. It ignites, and before it burns it lubricates. What keeps the surfaces inside the high-pressure pump and the fuel injectors from grinding against each other is the diesel flowing through them — they're made to very fine clearances.
Badly at the first, not at all at the second: that is petrol. The knocking comes from petrol being designed not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the lubrication your system rests on, and any pump running on that mixture is wearing itself.
Put those together and the shape of the trouble is plain. Not contact but movement is what does the harm. Where that petrol is only inside that tank, it is a problem of fuel, nothing more. Whatever a worn pump sheds travels on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has been working on the petrol is where a mechanical problem begins.
Petrol in a diesel in Bickley: how serious is it? Four situations
Fuelled, and never started: no case is better. That petrol is in that tank and only the tank, and the task is a drain and a flush where your car sits. This is the one scenario that can only really take place at a forecourt, since anywhere else your car has been driven to get there.
Started for a moment, or only the ignition on. With the system primed, the lines and filter already hold petrol that has come from that tank. Drain, flush, deal with the fuel filter: still normally simple.
Driven a couple of miles. Now the pump has spent those miles working on diluted fuel. How hard the vehicle was driven counts as much as how far, and this work covers that tank, your lines, your filter and fresh fuel through the entire circuit. Short trips, such as the school run to St George's, Bickley, Church of England Primary School, are one matter. Very different again: a run to London, under 10 miles away, or some miles on the M25, under 10 miles from Bickley, where the motor never stopped labouring hard.
Driven on till it complained — rattling, smoke, a lumpy idle, a dead throttle. The fuel is not behaving like diesel any more, and your engine is saying so. Stop where you are — on the verge on Southborough Road, at the kerb, down a side road — and do not move it. Permanent damage is very uncommon when a vehicle is stopped early, and the drain and flush-through that still go first take care of it.
Bickley motorists 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 mixture is all you get, since topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
If anything, the reverse is true. Myth: "A newer diesel can cope with a bit of petrol." At higher pressure, through more precise components: that is how a current diesel moves its fuel, and so the protection counts for more, not less.
This is the one that catches people. Myth: "If it starts and drives, there's no harm done." The driver of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the damage stops there. Feed petrol to a diesel and it normally fires up, ticks over and drives away as if nothing has happened — all while its pump is wearing. Being able to run isn't proof of being fine.
An old fix for a different issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol thinned is put back by it — and later, the tank still holds the petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol sits in the filter and lines, waiting to go right back through the pump on the next start. Also, a can of petrol drained at the kerbside is truly risky.
How does petrol in a diesel take place?
A careless moment is rarely the cause, and no one means to do it. A diesel nozzle mostly won't go into a petrol vehicle, yet the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake simple, and just in that direction.
It occurs when routine and your car stop matching. A new car, a hire car or a courtesy car. Two vehicles on one drive, one petrol, one diesel. A well-known forecourt with the pumps in a different order. A rushed fill en route to the nearest station with a train to catch. Precisely the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. With rain, a call arriving, or children to deal with, the hand simply does what it always has.
Bickley people: how to avoid petrol in a diesel next time
- Green for unleaded and black for diesel is normal in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- Check the filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in any vehicle you do not know.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- Before the nozzle comes off the pump the first time you fill a hired or new motor, say "diesel" aloud. Silly, yes, but 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 pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop checking the pump.
- Stop the moment you realise. Less petrol in your tank makes a thinner blend. It does not change what to do next, which is still not to start it.
Petrol already in a diesel around Bickley? Begin here
Then, there is just a short order of things. Don't turn your ignition on, and do not fire it up. Still at the forecourt, at BP or anywhere else? Ask the staff to help you roll the vehicle away from the pump. Then phone 0333 366 0103 and tell us what went in, about how much, and whether it's run.
Corrosion and deposits are the issue with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Bickley page.
Why one petrol in a diesel job in Bickley costs more than another
There is no fair single price for this, since the four scenarios above are four different jobs. Mostly, the cost moves with which situation you are in. The share counts next, meaning how much of the tank is petrol, followed by the location of your car and whether reaching it is safe for a technician.
Ahead of any quote, not after, come three questions: the fuel that got in, its quantity, and if it has run. That's why. Their answers are what turn a range into one firm number.
About Bickley itself
Bickley is a suburban area in the London Borough of Bromley, situated approximately 10 miles southeast of central London. Bickley sits at an elevation of around 75 metres, with its detached housing stock reflecting the area's character. Bickley is bordered by nearby places such as Widmore, Southborough, and Sundridge, and is home to a population of around 4203 residents. Bickley remains a predominantly residential community with a mix of local amenities and commuter links to London.
Bickley and Greater London: where our fuel drain cover runs
Widmore, Southborough and Sundridge are among the places near Bickley that the same vans work, answering petrol in diesel call-outs across Bickley's BR postcode area. Our technicians drain wherever your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump around Bickley, right now?
The best position there is, then — that's where you are. Keep the vehicle switched off, then ring.