Bolney: Petrol in a Diesel Car? How Worried to Be
Not started? Then less worried than you probably are. Everyone in Bolney begins with "have I wrecked it?", and the honest answer is normally no: petrol resting inside the tank of any diesel remains harmless till priming, cranking or driving pulls it into the system. Keep it like that: leave your engine off then ring Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's gone, and how to stop it from happening a second time: that's the rest of this page.
Inside the engine: what petrol in a diesel does
Two jobs fall to diesel on its route round a motor. Lubricating comes before burning; it does both. The high-pressure fuel pump and the injectors are made to extremely fine clearances, and your diesel passing through them is what keeps those surfaces from grinding against each other.
Petrol does the first task poorly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is runnier than diesel and strips out the protection your fuel system depends on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where any clattering starts.
Taken together, they show the shape the problem takes. Contact doesn't do the damage — movement does. Petrol in a tank is a fuel issue. After the pump has been working on that petrol, a mechanical issue has begun: anything shed by a pump that is wearing travels downstream to the fuel injectors with the fuel.
Four scenarios our engineers see around Bolney: how serious is petrol in a diesel?
The best case there can be: filled up, never started. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol held in that tank alone, it is cleared and rinsed on the spot, and nothing more is needed.
A moment's running, or merely the ignition on. Petrol has left your tank and got to the fuel filter and the lines, since your system has been primed. Normally little more than emptying, flushing and seeing to the filter, so still simple.
Driven a few miles. Now the pump has spent those miles working on thinned fuel. How hard your car was driven matters as much as how far, and the work takes in that tank, the fuel lines, the fuel filter and fresh fuel through the entire circuit. A school run to Bolney CofE Primary School is one matter. Getting as far as Brighton and Hove, under 15 miles away, makes a very different task — as does any distance on the M23, under 10 miles from Bolney, with the engine working hard all the way.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and your motor is saying so. Leave it wherever it stops: a lay-by, a side street, the verge on Ryecroft Road. The fuel drain and flush still go first, and they take care of it: when a car is stopped quickly, lasting damage is very rare.
Bolney people and the petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A bigger tank of the same mix is all it gives, because topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that guidance supposes.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. Lubrication matters more on newer diesels, not less, since their fuel runs through finer parts at higher pressure.
Myth: "If it starts and drives, there's no harm done." This is the one that catches motorists. A petrol motor fed diesel usually will not run, so the motorist stops and the harm stops with them. Whilst your pump wears, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Being able to run isn't the same as being fine.
An outdated fix for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive it home." What petrol has thinned remains thinned, and the petrol remains in the tank regardless.
If the motor has been run, part of that petrol sits in your filter and the fuel lines, not the tank — and the next start sends it right back through the pump. So the myth "drain your tank yourself and you are sorted" does not stand up. And, a can of petrol filled at the roadside is genuinely risky.
Why petrol in a diesel happens so easily
It is seldom carelessness, and nobody does it on purpose. A diesel nozzle generally won't go into a petrol car, but the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error easy, and just in that direction.
When routine and the car stop matching, it happens. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the driveway. The pumps in a different order on a well-known forecourt. Filling up in a hurry en route to Wivelsfield, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Avoiding petrol in a diesel next time you fill up around Bolney
- 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 motor you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of cars print the fuel type there.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key if a household has one of each. So label it.
- Before the nozzle leaves the pump the first time you fuel a hired or new vehicle, say "diesel" out loud. Silly, perhaps, yet it does the trick.
- Mistakes like this are straightforward to make whilst your mind is on something else, so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to reject a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop checking the petrol pump.
- Noticing it mid-fill? Stop at once. A weaker mixture follows from less petrol in your tank, yet the next stage stays the same: don't fire it up.
Put petrol in a diesel around Bolney already?
The order of things is brief, then. Leave it unstarted, with the ignition switched off as well. Still on the forecourt, at Merco or anywhere else? Ask the staff to help you roll it away from the pump. What went in, about how much, and whether it has run: tell us those when you call 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate issue — Bolney has a page all for it.
Why one petrol in a diesel task in Bolney costs more than another
The four scenarios above are four separate tasks, so no single quote for this would be fair. What moves the cost is mostly which of them you're in. The share matters next, meaning how much of your tank is petrol, and then the location of the car and whether reaching it is safe for a technician.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and that is the reason. The answers turn a range into a straight figure.
About Bolney, for a moment
Bolney is a small village in West Sussex, situated inland at an elevation of 44 metres, approximately 12 miles north of Brighton and Hove. Bolney has a population of around 637 people, with predominantly detached housing. Bolney is close to nearby places such as Crosspost, Twineham Green, and Warninglid, and is about 35 miles south of London. Bolney remains a quiet rural community with a strong sense of local identity.
Across West Sussex and in Bolney: fuel drain cover
Crosspost, Twineham Green and Warninglid are among the places near Bolney that the same teams work, answering petrol in diesel call-outs across Bolney's RH postcode area. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
In Bolney and still at the petrol pump?
Then, you could not be in a better spot. Turned off it remains; then call.