How Worried Should You Be? Petrol in a Diesel Car in Awsworth
Less than you likely are, provided it has not been started. Everyone around Awsworth starts with "have I wrecked it?", and the honest answer is usually no: petrol resting in that tank of a diesel remains harmless until priming, cranking or driving draws it into the system. Keep it that way: leave your engine off then ring Petrol in Diesel. Further down, you will find what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Your engine and petrol in a diesel: what happens
Two jobs fall to diesel on its route round a motor. It combusts, and before it ignites it protects. Your high-pressure pump and the injectors are made to extremely fine tolerances, and the diesel passing through them is what keeps those surfaces from wearing against one another.
Badly at the first, not at all at the second: that is petrol. The clattering comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection the fuel system depends on, and any pump running on that blend is wearing itself.
Put those together and the shape of the issue is plain. The harm is done by movement, not by contact. A tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, carried by the fuel, into the fuel injectors further along, which is why a pump that has been working on that petrol is where a mechanical problem begins.
Four scenarios our engineers see around Awsworth: how serious is petrol in a diesel?
Fuelled up, never started. The best case there is. At a forecourt, and genuinely only there, that petrol is still limited to your tank — since everywhere else your car was driven to get to it. The job is draining and cleaning on the spot.
The ignition switched on, or a brief start. Petrol has left that tank and got to the fuel filter and the fuel lines, because the system has been bled. Drain, flush, see to the filter: still normally straightforward.
Driven a couple of miles. Now your pump has spent those miles running on diluted fuel. The work is that tank, your lines, your filter and fresh fuel through the whole system, and how hard the car was driven counts as much as how far. A school run to Awsworth Primary and Nursery School is one matter. A run as far as Nottingham, under 10 miles away, is a very different job. So is any distance on the M1, under 3 miles from Awsworth, where your engine has been labouring hard throughout.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is your motor signalling fuel that no longer acts like diesel. Whether it is the verge on Station Road, a lay-by or a side street, stop there and leave it. A car stopped quickly very seldom has lasting damage, because the drain and the flush-through, which still come first, sort it out.
What Awsworth drivers get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you're left with a bigger tank, still the same mix. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance presumes.
"Newer diesels can handle a little petrol" — a myth, and nearer the opposite. Lubrication counts more on current diesels, not less, since their fuel runs through smaller components at higher pressure.
"It starts, it drives, so no harm done" — the myth that catches most motorists than any other. Feed diesel to a petrol engine and it usually will not run, and so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it usually fires up, idles and pulls away as if nothing has happened — all the while its pump is wearing. Running doesn't mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an old workaround for a different fault. None of what petrol diluted is put back by it — and afterwards, that tank still contains that petrol.
The next start sends petrol back round the pump out of the fuel lines and the filter, where some of that sits after the engine has been run. That's why a DIY tank drain doesn't leave you sorted — a myth. Also, a can of petrol drained at the kerbside is truly risky.
How does petrol in a diesel occur?
Nobody does it on purpose, and it's seldom carelessness. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it simple.
Routine and your car falling out of step is when it occurs. A motor that is new to you — a hire car, on loan as a courtesy car, or brand new. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a familiar forecourt. Filling up in a rush en route to Ilkeston, with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver used to petrol: exactly when it takes place. The hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Next time you fill up in Awsworth: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is only a hint.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of vehicles print the fuel type there.
- One of each in the household? Label your key to the diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" aloud. Daft, yes, yet it works.
- Mistakes like this are simple to make whilst your mind is on something else, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a backstop, and keep checking the pump.
- Less petrol makes a thinner mix, so stop the moment you realise — though remembering that the next step is unchanged. It's still not to start the vehicle.
Already put petrol in a diesel in Awsworth?
The order of things is brief, then. Do not switch the ignition on, and don't start it. Ask the attendants to help you roll it clear of the petrol pump if you are still at the forecourt, whether that is Shell or somewhere else. Then ring 0333 366 0103 and tell us what was put in, roughly how much, and whether it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different fault — Awsworth has a page just for it.
One petrol in a diesel job around Awsworth costs more than another. Why?
The four scenarios above are four different jobs, so no single quote for this would be fair. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that went in as a share of what that tank takes, then the spot the car is in and whether a technician can reach it safely.
Three questions come first, before any quote, rather than after — what got in, how much, has it run — and that is the reason. Their answers are what turn a range into one firm number.
About Awsworth, for a moment
Awsworth is a village in Nottinghamshire, situated on the riverside at an elevation of 77 metres, with detached housing being the predominant type of accommodation. Awsworth lies approximately 6 miles from Nottingham and 113.7 miles from London, making it a commuter-friendly location. Awsworth is surrounded by nearby places such as Babbington, Cossall Marsh, and Giltbrook, and has a population of around 1512 residents. Awsworth enjoys a peaceful setting, with the River Erewash flowing nearby.
Awsworth and Nottinghamshire: where our fuel drain cover reaches
Babbington, Cossall Marsh and Giltbrook are among the places near Awsworth that the same teams work, answering petrol in diesel jobs across Awsworth's NG postcode area. You need not move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots where we work.
At the petrol pump in Awsworth, right now?
Then you are in the best position there is. Keep the car switched off, and ring.