Should You Worry? Petrol in a Diesel Car in Well End
If it hasn't been started, worry far less than you likely are. Petrol sitting in a diesel tank does nothing to your engine till something pulls it through your fuel system — the ignition priming your pump, your starter, or driving itself. So the truthful answer to the first question anyone in Well End asks, "have I wrecked it?", is generally no. To keep the car that way, call Petrol in Diesel then leave the engine alone. Below, you will find what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you again.
What petrol in a diesel does to your engine
On its way through an engine, diesel has two tasks. It burns, and before it burns it protects. The high-pressure pump and the fuel injectors are designed to very fine gaps, and the diesel passing through them is what keeps those surfaces from wearing against each other.
Of these two jobs, petrol manages the first badly and the second never. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on that mixture wearing itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
Put those together and the shape of the issue is plain. Not contact but movement is what does the damage. Petrol in a tank is a fuel problem. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
Well End, petrol in a diesel: four situations, from mild to significant
Fuelled, and never started: nothing beats it. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it is drained and purged right where it stands, and nothing more is needed.
A moment's running, or merely your ignition on. Petrol has left that tank and reached the filter and the lines, because your system has been primed. Still usually simple: drain, flush, and the fuel filter sorted.
Driven a few miles. Now your pump has spent these miles labouring on diluted fuel. Tank, lines, filter, then clean fuel run through the whole system: that is the work, and the way the vehicle was driven matters as much as the mileage. Short trips, like the school run to Claytons Primary School, are one thing. A run as far as St Albans, under 25 miles away, is a very different task. So is any mileage on the M40, under 3 miles from Well End, where the motor has been running hard throughout.
Driven until it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and your engine is telling you. Whether it is the verge on Wendover Road, a lay-by or a side road, stop there and leave it. The fuel drain and flush-through still go first, and they deal with it: if a car is pulled over early, long-term damage is very unusual.
Well End people and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice supposes.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Finer parts and higher pressure are the way a current diesel runs its fuel, and that makes the lubrication matter more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools people. Diesel in a petrol motor generally leaves a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually starts, idles and pulls away as if nothing happened — all while its pump is wearing. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different issue. That petrol is still inside your tank after that, and what it has diluted isn't put back.
Once the engine has run, part of the petrol sits in your filter and the lines, not that tank — and the next start sends it right back through the pump. So the myth "drain that tank yourself and you are sorted" does not hold. On top of that, petrol cleared into a can by the road is genuinely risky.
Why petrol in a diesel happens so easily
On purpose? Never. Through carelessness? Rarely, if ever. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol vehicle. That is how the forecourt makes it simple.
Routine and the vehicle getting out of step is how it occurs. A new vehicle, a hire car or a courtesy car. Two cars on one driveway, one petrol, one diesel. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill en route to Bourne End. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it happens. The hand repeats what it has always done when you add rain, a phone call or a back seat full of children.
Well End motorists: how to prevent petrol in a diesel next time
- The label is what counts, and so check the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on each forecourt.
- In a motor you don't know, look inside the flap over the filler or at the cap before your first fill: plenty of cars print the fuel there.
- One of each in the home? Mark the key to the diesel — a bright fob, a sticker — because meaning to remember is not enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It seems silly and it works.
- Mistakes like this are easy to make while 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 reject a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a backstop, and keep reading the pump.
- Less petrol means a weaker blend, so stop as soon as you notice — while remembering that your next stage is unchanged. It's still not to start it.
Petrol already in a diesel in Well End? Begin here
Then the order of things is brief. Do not turn the ignition on, and do not crank it. Yet at the forecourt, at Shell or anywhere else? Ask the staff to help you push the vehicle away from the petrol pump. Then phone 0333 366 0103 and tell us what went in, roughly how much, and if it's run.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits rather than lost lubrication — and it has its own page for Well End.
One petrol in a diesel job around Well End costs more than another. Why?
There's no honest single quote for this, because the four scenarios above are four separate jobs. Chiefly, your cost shifts with which one you are in. After that it's the proportion — how much petrol went in against how much the tank holds — and then where the vehicle is and whether our van can reach it safely.
Three questions come first, before quoting, instead of after — what was put in, how much, has it run — and this is the reason. With those replies, you get a straight figure instead of a range.
About Well End and where it is
Well End is a village in Buckinghamshire, situated inland at an elevation of 42 metres, approximately 25.8 miles from London. Well End lies near the villages of Bourne End and Fern, and is characterized by its predominantly detached housing stock. Well End remains a small, residential community with a population of around 913 people.
Across Buckinghamshire and around Well End: fuel drain cover
Well End rests in the SL postcode area, and the teams that answer petrol in diesel call-outs there work the spots around it as well — Bourne End, Fern and Sheepridge among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations we work, and the car does not need to move to us.
Still at the petrol pump around Well End?
The best position there is, then — that's where you are. Turned off it remains; then phone.