Christian Fields: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, provided it hasn't been started. "Have I wrecked it?" is the first question everyone around Christian Fields asks, and the honest answer is generally no, since petrol left in a diesel tank harms nothing until it is dragged through the fuel system — by ignition priming, by your starter, or by being driven. Keep it like that: leave your motor off then ring Petrol in Diesel. What petrol really does to a diesel, how to gauge how far it's gone, and how to stop it from happening again: that is the rest of this page.
Petrol in a diesel: what does it do to your engine?
Two tasks fall to diesel on its route round a motor. Before it burns, it lubricates — and then it combusts. Extremely fine tolerances are built into your injectors and the high-pressure pump, and just your diesel flowing through keeps their surfaces from grinding together.
Of those two tasks, petrol handles the first badly and the second not at all. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump running on the blend to wear itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the clattering.
The shape of the issue is plain when you put those together. Contact does not do the harm — circulation does. Where that petrol is only in the tank, it's a fault of fuel, nothing more. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors further on.
Four situations our engineers see in Christian Fields: how bad is petrol in a diesel?
Fuelled up, not once started. The best case there can be. Being on a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With that petrol held in that tank alone, it's drained and cleaned right where it stands, and nothing more is needed.
Started for a moment, or only the ignition on. Once primed, your system has pulled petrol out of that tank as far as the filter and your lines. Drain, flush, see to your filter: still normally easy.
The pump has worked a couple of miles on diluted fuel — that's what driving it does. Tank, lines, filter, then fresh fuel put through the whole circuit: that is this work, and the way your car was driven counts as much as the miles. Driving the kids to King's Farm Primary School is one sort of trip. Very different once more: a trip to Southend-on-Sea, under 25 miles away, or some miles on the M2, under 3 miles from Christian Fields, where the engine never stopped labouring hard.
Driven on till it complained — clattering, smoke, a ragged idle, a soft throttle. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Whether it's the verge on Hawkins Avenue, a lay-by or a side street, stop there then leave it. Lasting damage is very unusual if a car is stopped soon, and the drain and flush-through that still go first take care of it.
Stories Christian Fields people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed when you top up — the tank just holds more of the same blend. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Smaller parts and higher pressure are the way a modern diesel runs its fuel, and that makes the protection matter more, not less.
This is the one that catches people. Myth: "If it starts and drives, there is no damage done." A petrol engine fed diesel generally will not run, and so the motorist stops and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile the pump grinds. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. The petrol is still inside that tank after that, and what it has diluted isn't put back.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol sits in your filter and lines, ready to go straight back through your pump on the next start. Clearing petrol into a can by the roadside is also genuinely risky.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol motor. That's how the forecourt makes it straightforward.
It occurs when habit and the car stop matching. Any motor that's new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. A well-known forecourt with the pumps in a different order. Rushing for a train outside Gravesend and filling up en route. Exactly the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. The hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel on your next fill-up around Christian Fields
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- The first fill in a new car is the time to check your filler flap — on it, or on the cap, plenty of cars state the fuel they take.
- One of each in the house? Label the key to the diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" aloud. Daft, yes, but it works.
- Mistakes like this are easy to make while your mind is on something else, and so your phone goes 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 petrol pump.
- Stop the moment you notice. Less petrol in your tank makes a weaker blend. It doesn't change what to do next, which is still not to crank it.
Put petrol in a diesel around Christian Fields already?
Short and simple, then, is the order of things. Starting it is out, and so is turning on the ignition. Still at the forecourt, at Shell or anywhere else? Ask the attendants to help you roll the vehicle clear of the petrol pump. Next, 0333 366 0103. We'll ask what went in, about how much, and if it has been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a separate fault — Christian Fields has a page all for it.
Christian Fields petrol in a diesel tasks: why one costs more than another
An honest single price does not exist here: four situations, four separate jobs. Which of them you're in is chiefly what moves your cost. Two things come after that: the petrol that got in as a proportion of what the tank holds, then the place the vehicle is in and whether our van can reach it safely.
That's why our technicians ask three queries before costing rather than after: what went in, how much, and whether it's run. Those answers are what change a range into one firm number.
About Christian Fields
Christian Fields is a suburban area located on the coast of Kent, with an elevation of 63 metres above sea level. Christian Fields sits near several other local places, including Parrock Farm, Kings Farm, and Singlewell, and is approximately 16.7 miles from Southend-on-Sea. Christian Fields is characterized by its predominantly terraced housing stock, which reflects the typical architecture of the region. Christian Fields is also relatively close to London, at a distance of 22.6 miles.
Across Kent and around Christian Fields: fuel drain cover
Parrock Farm, Kings Farm and Singlewell are among the locations near Christian Fields that the same teams work, answering petrol in diesel calls across Christian Fields's DA postcode area. The car does not need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the pump around Christian Fields, still?
No position is better: that is where you are. Switched off it remains; then ring.