Rimbleton: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less anxious than you likely are. Till your ignition primes the pump, the starter turns, or your car is driven, petrol in a diesel tank just sits there and does nothing. Which means the honest reply to the first Rimbleton question — "have I ruined it?" — usually no. Leave the engine off and call Petrol in Diesel — that keeps it that way. Below, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Inside the engine: what petrol in a diesel really does
Two tasks fall to diesel on its route through a motor. Before it ignites, it protects — and then it ignites. The high-pressure pump and your injectors are designed to extremely fine clearances, and your diesel passing through them is what keeps those surfaces from grinding against each other.
The second task petrol doesn't 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 strips out the protection the 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 knocking comes.
Put these together and the shape of the issue is clear. The damage is done by movement, not by contact. Where that petrol is only in your tank, it is a fault of fuel, nothing more. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the injectors further on.
Four situations our engineers see around Rimbleton: how serious is petrol in a diesel?
The best case there can be: filled up, never started. That petrol is inside that tank and only your tank, and the job is a drain and a flush where the vehicle stands. This is the one scenario that can only really take place at a forecourt, because anywhere else the vehicle has been driven to get there.
Started for a second, or just your ignition on. Once primed, the fuel system has drawn petrol out of that tank as far as the fuel filter and the fuel lines. Drain, flush, deal with the filter: still usually easy.
The pump now worked a couple of miles on diluted fuel — that's what driving the vehicle does. How hard your car was driven counts as much as how far, and the work takes in the tank, the lines, your filter and clean fuel through the whole system. Driving the kids to the local primary school is one sort of trip. Any mileage on the M90, under 10 miles from Rimbleton, means your engine has worked hard throughout, and a run to Dunfermline, under 15 miles away, makes a very different task too.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. What you are hearing is your motor reporting fuel that no longer acts like diesel. Stop wherever you are — the verge on Aline Court, a lay-by, a side street — then leave it where it is. A vehicle stopped quickly very rarely has lasting damage, since the fuel drain and the flush-through, which still come first, deal with it.
Rimbleton motorists and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up takes out nothing; it gives you a fuller tank of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice presumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise parts: that is how a modern diesel moves its fuel, and so the lubrication matters for more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no harm done." The motorist of a petrol engine fed diesel usually stops, because it will not run, and the damage stops with them. Feed petrol to a diesel and it usually starts, ticks over and drives away as if nothing has happened — all the while its pump is wearing. Fine and running are not the same at all.
An old fix for a different problem is behind this one. Myth: "Add some two-stroke oil and drive it home." The petrol is still inside that tank after that, and whatever it has diluted isn't put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol sits in the filter and lines, ready to go right back through the pump on your next start. It's also really dangerous to drain petrol into a can by the roadside.
How does petrol in a diesel happen?
It is rarely carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol motor at all. So the error runs one way.
When habit and the car stop matching, it happens. Courtesy car, hire car, or a car that's brand new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. A hurried fill en route to Markinch with a train to catch. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is precisely the moment it occurs. Add a back seat full of kids, a phone call or rain, and habit takes over.
Rimbleton people: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Go by the label on the pump, not the colour.
- The first fill in an unfamiliar motor is the time to check the filler flap — on it, or on the cap, plenty of cars state the fuel to use.
- One of each in the home? Label your key to your diesel — a coloured fob, a sticker — since meaning to remember isn't enough.
- "Diesel", aloud, before you pick up the nozzle — each time a new or hired car gets its first tank. It sounds silly. It does the trick.
- While you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Some diesels come with a filler designed to block a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Spotting it halfway? Stop there and then. A thinner blend results from less petrol in your tank, yet the next step remains the same: don't crank it.
Rimbleton: already put petrol in a diesel?
Then the order of things is short. Leave it unstarted, with the ignition off too. Ask the attendants to help you push it clear of the petrol pump if you are still on the forecourt, whether that is Shell or somewhere else. Ring 0333 366 0103 next, with three facts — your fuel, the rough amount, and whether it has run.
Say so if it was AdBlue instead of petrol: it is a different issue, with its own page for Rimbleton, since AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel job in Rimbleton costs more than another
A fair single price doesn't exist here: four scenarios, four separate jobs. Which of them you are in is chiefly what moves the cost. Where the vehicle is counts too, and whether our van can safely reach it, after the proportion of petrol to what your tank takes.
What got in, how much, and if it's run — three questions our engineers ask before costing, not after, for precisely that reason. A range becomes a straight figure once those replies are in.
About Rimbleton, for a moment
Rimbleton is a suburban area in Fife, situated inland at an elevation of 115 metres, with terraced housing being the predominant type of accommodation. Rimbleton lies approximately 13 miles from Dunfermline and is surrounded by other nearby places such as Caskieberran and East Finglassie. Rimbleton has a population of around 3888 residents and is located about 346 miles north of London. Rimbleton forms part of the wider residential area around Dunfermline.
Fuel drain cover around Rimbleton and across Fife
Our vans answering petrol in diesel jobs around Rimbleton, in the KY postcode area, equally work the spots near it, Caskieberran, South Parks and East Finglassie included. We drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump in Rimbleton, still?
In that case, you could not be in a better position. Leave the vehicle switched off, then ring.