Should You Worry? Petrol in a Diesel Car in Luddenden
If it hasn't been started, worry less than you likely are. Till your ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank just sits there and does no harm. Which makes the honest reply to that first Luddenden question — "have I ruined it?" — normally no. Leave the engine off and call Petrol in Diesel — that keeps it that way. Read on for three things: the effect petrol has inside a diesel engine, 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 motor
Two jobs fall to diesel on its journey round a motor. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure pump and the fuel injectors from wearing down against each other is your diesel flowing through them — they're built to very fine gaps.
The second task petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running on the mixture wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you get the rattling.
The shape of the issue is clear when you put those together. It is circulation that does the damage, not contact. Petrol in the tank is a fuel issue. After your pump has been labouring on that petrol, a mechanical issue has started: anything shed by a pump that is wearing travels downstream to the injectors with the fuel.
How bad is petrol in a diesel? Four scenarios our technicians see around Luddenden
Filled up, and not started: no case is better. On a forecourt, and really only there, the petrol is still confined to your tank — because anywhere else your car was driven to get to it. The job is emptying and cleaning on the spot.
The ignition turned on, or a brief start. The system has been primed, and so petrol has left the tank and reached your filter and your lines. Drain, flush, see to your filter: still normally simple.
Those few miles driven meant the pump running on fuel thinned by petrol the whole way. The work is the tank, your lines, the filter and fresh fuel through the whole system, and how hard the vehicle was driven counts as much as how far. Driving the children to Luddenden CofE School is one kind of trip. A run as far as Bradford, under 10 miles away, is a very different task. So is any mileage on the M62, under 10 miles from Luddenden, where your engine has been working hard throughout.
Driven on until it complained — rattling, smoke, an uneven idle, a soft throttle. The motor is telling you your fuel is no longer behaving like diesel. Whether it is the verge on Stocks Lane, a lay-by or a side road, stop there and leave it. A car pulled over quickly very seldom has permanent damage, as the drain and the flush-through, which still come first, sort it out.
What Luddenden motorists get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — your tank simply holds more of the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It does not.
If anything, the reverse is true. Myth: "A current diesel can cope with a bit of petrol." Lubrication counts more on modern diesels, not less, because their fuel passes through more precise parts at higher pressure.
One myth that catches motorists out: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it usually will not run, and so the driver stops — and the harm stops with them. Whilst your pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Running is not the same as fine.
An outdated fix for a separate issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It does not put back what petrol has diluted, and the petrol is still in the tank later on.
The next start sends petrol back round your pump from the lines and the fuel filter, where some of that ends up once your engine has been run. That's why draining your tank yourself doesn't leave you sorted — a myth. And, a can of petrol drained by the roadside is genuinely risky.
Petrol in a diesel: how does it happen?
On purpose? Never. Through carelessness? Rarely, if ever. A diesel nozzle generally will not fit a petrol motor, but the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake simple, and just in that direction.
The moment habit stops matching your car is the moment it occurs. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. A forecourt you know, only with its pumps arranged differently. A train to catch, and a rushed fill en route to Mytholmroyd. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: precisely when it happens. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Luddenden drivers: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is just a clue.
- The first fill in a new vehicle is the time to check the filler flap — inside it, or on the cap, many cars state which fuel to use.
- Mark the 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.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" aloud. Daft, perhaps, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck your phone away then keep your mind on the pump.
- Add-on devices are available for cars without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside the tank means a weaker mixture. It doesn't change what to do next, which is still not to fire it up.
Already put petrol in a diesel in Luddenden?
Then the order of things is short. Leave it unstarted, with your ignition switched off too. Ask the attendants to help you push it clear of the petrol pump if you are still at the forecourt, whether that's BP or somewhere else. Then call 0333 366 0103 and tell us what went in, roughly how much, and whether it has run.
If it was AdBlue rather than petrol, say so. That is a separate fault — corrosion and deposits rather than lost lubrication — and it has its own page for Luddenden.
One petrol in a diesel job around Luddenden costs more than another. Why?
An honest single quote does not exist here: four scenarios, four separate tasks. Chiefly, your cost moves with which situation you're in. Two things follow that: the petrol that went in as a proportion of what the tank holds, then the spot the car is in and whether our van can get to it safely.
What got in, how much, and if it has run — three questions our engineers ask before pricing, not after, for exactly that reason. A range turns into a straight figure when the answers are in.
About Luddenden itself
Luddenden is a small village in West Yorkshire, situated on the banks of a river at an elevation of 114 metres. Luddenden lies approximately 8.6 miles west of Bradford and is characterised by its predominantly terraced housing. Luddenden is close to nearby villages such as Midgley and Luddenden Foot, and is part of a wider network of rural communities in the region.
Across West Yorkshire and in Luddenden: fuel drain cover
Midgley, Luddenden Foot and Booth are among the locations near Luddenden that the same teams work, answering petrol in diesel calls across Luddenden's HX postcode area. We drain where the car 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 Luddenden, right now?
No position is better: that's where you are. Keep it off. Ring.