Rushgreen: Petrol in a Diesel Car? How Worried to Be
Provided it hasn't been started, worry less than you probably are. "Have I wrecked it?" is the first question anyone around Rushgreen asks, and the truthful answer is usually no, because petrol resting in a diesel tank harms nothing till it is drawn through the fuel system — by ignition priming, by the starter, or by being driven. To leave it like that, call Petrol in Diesel then leave the engine alone. Below, this page sets out what petrol actually does inside a diesel, how far it might have gone, and how to stop it happening to you again.
The motor and petrol in a diesel: what happens
Passing through a motor, diesel is doing two things at the same time. Before it combusts, it protects — then it combusts. Designed to extremely fine tolerances, the injectors and the pump rely on your diesel flowing through them to keep their surfaces from wearing against one another.
Of these two jobs, petrol manages the first badly and the second never. A pump running on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the protection the fuel system relies 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 rattling comes.
The shape of the trouble is plain when you put those together. The harm is done by circulation, not by contact. Any tank with petrol in it is a fuel issue. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to your injectors downstream.
How serious is petrol in a diesel? Four scenarios our technicians see in Rushgreen
Filled but not once started — as good as it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol kept inside your tank alone, it's emptied and flushed on the spot, and nothing more is needed.
Started for a second, or only the ignition on. The fuel system has been primed, and so petrol has left your tank and reached your filter and your lines. That's generally still an easy job — a drain, a flush, and the fuel filter seen to.
A few miles driven, and your pump has spent every one of them working on weakened fuel. How hard your car was driven matters as much as how far, and this work takes in the tank, the lines, the fuel filter and clean fuel through the whole system. The school run to Oughtrington Primary School is one thing. Driving as far as Salford, under 10 miles away, makes a very different job — as does any distance on the M56, under 3 miles from Rushgreen, with the motor working hard the whole time.
Driven on until it protested — clattering, smoke, a ragged idle, a dead throttle. The motor is telling you your fuel is no longer behaving like diesel. Whether it's the verge on Bucklow Gardens, a lay-by or a side road, stop there and leave it. What goes first is still the fuel drain and flush, and that takes care of it, with permanent damage very uncommon when a vehicle is pulled over soon.
Petrol in a diesel myths Rushgreen motorists hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Topping up takes out nothing; it gives you a fuller tank of the same mix. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." A newer diesel runs its fuel through more precise components at higher pressure, which makes the protection count more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops there. Feed petrol to a diesel and it usually fires up, ticks over and pulls away as if nothing happened — all while its pump is wearing. Fine and running are not the same thing.
Myth: "Add some two-stroke oil and drive it home." It's an outdated fix for a distinct fault. None of what petrol weakened is put back by it — and afterwards, your tank still contains that petrol.
The next start draws petrol back round your pump out of the fuel lines and the filter, where some of it sits after the engine has been run. That's why draining the tank yourself does not sort it — a myth. It's also genuinely risky to drain petrol into a can at the roadside.
Why petrol in a diesel occurs so easily
Nobody does it on purpose, and it's seldom carelessness. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the slip runs one way.
The moment routine stops matching your car is the moment it occurs. Hire cars, courtesy cars, and vehicles that are new to you. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a well-known forecourt. A rushed fill en route to Glazebrook with a train to catch. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Throw in rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up in Rushgreen: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on each forecourt. The label is what counts.
- The first fill in an unfamiliar car is the time to check the filler flap — on it, or on the cap, plenty of cars state which fuel they take.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, in a house with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It sounds daft and it works.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and add-on devices are available for the rest. Treat it as a backstop, then keep reading the pump.
- Spotting it mid-fill? Stop at once. A thinner mixture results from less petrol inside that tank, yet the next step remains the same: do not crank it.
Put petrol in a diesel around Rushgreen already?
Short and simple, then, is the order of things. Starting it is out, and so is switching on your ignition. If you are still on the forecourt — Shell or anywhere else — ask the staff to help you roll the car away from the petrol pump. Then phone 0333 366 0103 and tell us what got in, about how much, and if it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Rushgreen has a page just for it.
What makes one Rushgreen petrol in a diesel task cost more than the next
An honest single quote does not exist here: four situations, four separate tasks. Mostly, your cost moves with which one you're in. Beyond that it's the proportion — how much petrol went in against how much that tank takes — and then where the vehicle is and whether our van can reach it safely.
Ahead of any quote, not after, we ask three queries: the fuel that got in, its quantity, and if it's run. That's why. Those answers turn a range into a straight figure.
About Rushgreen and its setting
Rushgreen is a suburban area in Cheshire, situated on the riverside with an elevation of around 20 metres. Rushgreen lies near several nearby places, including Oughtrington, Lymm, and Heatley, and is approximately 9.5 miles from the city of Salford. Rushgreen has a population of around 2717 people and predominantly consists of semi-detached housing. Rushgreen is located in the North West region of England, about 162.9 miles from London.
Rushgreen and Cheshire: where our fuel drain cover reaches
Rushgreen waits in the WA postcode area, and the vans that answer petrol in diesel calls there work the places near it as well — Oughtrington, Lymm and Heatley among them. The car doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump in Rushgreen?
Then, you could not be in a better spot. Keep it off. Call.