Westbourne: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry less than you likely are. Everyone in Westbourne starts with "have I wrecked it?", and the honest answer is normally no: petrol resting in that tank of any diesel stays harmless until priming, cranking or driving pulls it into your fuel system. To leave the vehicle like that, call Petrol in Diesel and leave your engine alone. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you never repeat it.
What petrol in a diesel does to the engine
Diesel has two tasks on its way through an engine. Oiling comes before burning; it does both. Your high-pressure pump and the injectors are designed to extremely fine tolerances, and the diesel passing through them is what keeps those surfaces from grinding against each other.
The second job petrol does not do at all, and the first it does badly. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump on that mixture to wear itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the knocking.
Put these together and the shape of the trouble is plain. Not contact but circulation is what causes the harm. All a tank with petrol in it amounts to is a fuel problem. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors beyond it.
Four situations our engineers see around Westbourne: how bad is petrol in a diesel?
Filled up, and never started: nothing beats it. Just that tank has petrol in it, so the job is clearing that tank and flushing the system where the vehicle sits. This situation can only really 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, the lines and filter already hold petrol that has come from that tank. That is normally still an easy task — a drain, a flush, and your filter seen to.
A few miles driven, and the pump has spent every one of them labouring on thinned fuel. How hard the vehicle was driven matters as much as how far, and this work takes in your tank, your lines, your filter and clean fuel through the whole system. The school run to St Michael's Church of England Primary School is one matter. Any distance on the M27, under 25 miles from Westbourne, means your engine has worked hard throughout, and a run to Salisbury, under 25 miles away, is a very different task too.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. The motor is telling you the fuel is no longer acting like diesel. Pull up on the spot — on the verge on Marlborough Road, at the kerb, down a side road — and do not move it again. Long-term damage is very uncommon if a vehicle is pulled over quickly, and the fuel drain and flush that still come first sort it out.
Westbourne motorists and the petrol in a diesel myths they hear
False: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all you get, since topping up removes nothing. A diesel fuel system does not tolerate petrol by percentage in the way that advice presumes.
Not so: a modern diesel copes with a bit of petrol. Rather, the opposite. At higher pressure, through smaller parts: that's how a modern diesel handles its fuel, 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 motorist of a petrol engine fed diesel normally has no choice but to stop, because it will not run, and the harm stops with them. A diesel fed petrol generally starts, idles and drives away as though nothing has happened, while your pump wears. Being able to run is not proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct issue. None of what petrol weakened is put back by it — and afterwards, that tank still contains that petrol.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol sits in the fuel filter and lines, waiting to go straight back through your pump at the next start. On top of that, petrol emptied into a can by the road is genuinely dangerous.
Why petrol in a diesel takes place so easily
It is seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol car at all. So the mistake runs one way.
Habit and your car getting out of step is when it takes place. Hire cars, courtesy cars, and motors that are new to you. A household with one petrol and one diesel on the drive. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill on the way to Branksome. A new-to-you diesel Renault Clio, its first fuelling, and a motorist used to petrol: exactly when it happens. Add a back seat full of kids, a phone call or rain, and the hand takes over.
How to avoid petrol in a diesel at your next fill-up in Westbourne
- Green for unleaded and black for diesel is normal in the UK — yet not on each forecourt. Trust the label on the petrol pump, not the colour.
- In a car you do not know, look inside the flap over your filler or at the cap before the first fill: many cars state the fuel there.
- One of each in the home? Mark the key to your diesel — a coloured fob, a sticker — since meaning to remember is not enough.
- It seems silly and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Tuck your phone away. This is an easy mistake to make whilst you are thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to refuse a petrol nozzle, and add-on devices are available for vehicles without one. They are a backstop, not a reason to stop reading the petrol pump.
- As soon as you realise, stop: less petrol in your tank makes a weaker blend. What to do next does not change, though — still don't crank it.
Petrol already in a diesel around Westbourne? Start here
The order of things is short, then. Do not switch the ignition on, and do not crank it. Ask the attendants to help you push it away from the pump if you are still at the forecourt, whether that is Tesco or anywhere else. Then ring 0333 366 0103 and tell us what was put in, about how much, and whether it's run.
If it was AdBlue instead of petrol, say so. That's a different problem — corrosion and deposits instead of lost lubrication — and it has its own page for Westbourne.
What makes one Westbourne petrol in a diesel task cost more than the next
A fair single price does not exist here: four scenarios, four separate tasks. What moves the cost is chiefly which of them you are in. Beyond that it is the share — how much petrol was put in against how much your tank holds — and after that where the vehicle is and whether a technician can reach it safely.
What went in, how much, and if it has run — three queries our technicians ask before costing, not after, for exactly that reason. With those replies, you get a straight figure instead of a range.
About Westbourne, briefly
Westbourne is a coastal suburban area in Dorset, situated near the popular beaches of Bournemouth and close to the nearby places of Alum Chine, West Cliff, and Branksome Park. Westbourne sits at an elevation of around 45 metres, with its predominant housing stock consisting of flats. Westbourne is located approximately 24.6 miles from Salisbury and 94.1 miles from London, making it a popular residential area for those who want to be near the coast but still within reach of larger cities.
Westbourne and Dorset: where our fuel drain cover reaches
The vans answering petrol in diesel call-outs around Westbourne, in the BH postcode area, also work the spots around it, Alum Chine, West Cliff and Branksome Park among them. The car doesn't need to come to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Westbourne and still at the petrol pump?
Then you're in the best spot there is. Leave the vehicle turned off, then ring.