How Worried Should You Be? Petrol in a Diesel Car in Low Bentley
Unstarted? Then less worried than you probably feel. Petrol sitting in a diesel tank does nothing to the engine until something draws it through the system — the ignition priming the pump, the starter, or the drive on its own. So the honest answer to the first query anyone in Low Bentley asks, "have I wrecked it?", is normally no. Leave your motor off and ring Petrol in Diesel — that is how you keep it like that. What petrol actually does to a diesel, how to gauge how far it has travelled, and how to stop it from happening a second time: that's the rest of this page.
What petrol in a diesel does to the motor
On its way through a motor, diesel has two jobs. It lubricates first, and after that does it burn. Your high-pressure pump and the injectors are built to very fine gaps, and your diesel passing through them is what stops those surfaces from grinding against each other.
The second job petrol does not do at all, and the first it does poorly. It's thinner than diesel and strips away the protection the fuel system rests on, so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the knocking comes from.
Put those together and the shape of the trouble is plain. Contact doesn't do the harm — movement does. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds goes on, borne by your fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical problem starts.
Petrol in a diesel around Low Bentley: how serious is it? Four cases
Filled but never started — as good as it gets. Just your tank has petrol in it, and so the task is clearing your tank and cleaning your system where the car stands. This scenario can only really occur on a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition turned on, or a brief start. With the system primed, the lines and filter now hold petrol that has come from your tank. Usually nothing more than clearing, purging and seeing to the fuel filter, and so still easy.
Your pump has spent a couple of miles on thinned fuel — that is what driving the car does. Mileage is only half of that; how hard it was driven counts equally. Either way this work includes the tank, your lines, the fuel filter and clean fuel through the whole circuit. On the school run to St Michael and All Angels CofE Primary & Pre School, the mileage is short. Any distance on the M606, under 3 miles from Low Bentley, means your engine has worked hard throughout, and a run to Bradford, under 5 miles away, is a very different task too.
Driven on until it complained — clattering, smoke, an uneven idle, a soft throttle. What you are hearing is your engine signalling fuel that no longer runs like diesel. Whether it's the verge on Riding Hill, a lay-by or a side street, stop there then leave it. What comes first is still the fuel drain and flush, and that deals with it, with long-term damage very uncommon if a vehicle is stopped quickly.
What Low Bentley motorists get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up removes nothing; it gives you a fuller tank of the same mix. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance assumes.
If anything, the opposite holds. Myth: "A current diesel can cope with a bit of petrol." Protection matters more on newer diesels, not less, since their fuel runs through finer parts at higher pressure.
"It starts, it drives, and so no harm done" — the myth that trips up most people than any other. Diesel in a petrol motor usually leaves a motor that won't run: the driver stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Running is not the same as fine.
An outdated workaround for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." The petrol is still inside that tank afterwards, and whatever it has diluted is not put back.
Myth: "Drain that tank yourself and you are sorted." After the motor has run, some of the petrol is no longer in the tank: it's in your filter and your lines, and it goes right back through your pump on your next start. Besides, petrol cleared into a can by the road is truly dangerous.
How it happens: petrol in a diesel
A careless moment is seldom the cause, and no one means to do it. A diesel nozzle generally will not fit a petrol car, but the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake straightforward, and only in that direction.
It occurs when habit and the vehicle stop matching. A new motor, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. Your usual forecourt, its pumps now in a different order. Filling up in a hurry on the way to Low Moor, with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Passat in front of you on the forecourt for its first tank — that is when. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Low Bentley people: how to prevent petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is only a clue.
- Plenty of vehicles state the fuel type inside your filler flap or on the cap, and so check there on the first fill in a car you do not know.
- One of each in the household? Mark your key to the diesel — a coloured fob, a sticker — since intending to remember is not enough.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" aloud. Silly, perhaps, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for the remainder. Count it as a safety net, and keep checking the petrol pump.
- Less petrol means a weaker mix, and so stop the moment you notice — while remembering that your next stage is unchanged. It's still not to start the car.
Put petrol in a diesel in Low Bentley already?
Then the order of things is brief. Do not switch the ignition on, and do not start it. Ask the attendants to help you push it away from the petrol pump if you are still on the forecourt, whether that's Tesco or anywhere else. Ring 0333 366 0103 next, with three facts — the fuel, the approximate amount, and whether it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate issue — Low Bentley has a page just for it.
Why one petrol in a diesel task around Low Bentley costs more than another
There is no fair single price for this, since the four scenarios above are four different tasks. The scenario itself does most of the work of moving the cost. Next it's the ratio — how much petrol was put in against how much that tank holds — and then where the vehicle is and whether our van can reach it safely.
That's why we ask three questions before costing rather than after: what was put in, how much, and if it's run. Those replies are what change a range into one firm number.
About Low Bentley
Low Bentley is a small hamlet situated on the riverside in West Yorkshire, with a mix of semi-detached housing and a population of around 1725 residents. Low Bentley sits at an elevation of 232 metres, close to the city of Bradford and near other local places such as Shelf and Beck Hill. Low Bentley is located near the wooded hills and valleys of the Yorkshire countryside, with the larger city of Bradford just 3.2 miles away. Low Bentley remains a quiet residential area with easy access to local amenities.
Fuel drain cover across West Yorkshire, Low Bentley included
Shelf, Beck Hill and Woodside are among the locations near Low Bentley that the same teams work, answering petrol in diesel call-outs across Low Bentley's HX postcode area. The vehicle does not need to move to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump around Low Bentley, right now?
No position is better: that's where you are. Keep it off. Phone.