Blendon: Petrol in a Diesel Car? How Worried to Be
Probably less than you are now — provided nobody has started the car. "Have I wrecked it?" is the first question everyone around Blendon asks, and the truthful answer is normally no, since petrol resting in a diesel tank harms nothing till it's dragged through the system — by ignition priming, by the starter, or by being driven. Keep it like that: leave the motor off and phone Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and ways to make sure you don't repeat it.
What petrol in a diesel does to the engine
Diesel does two jobs on its way through an engine. Lubricating comes before burning; it does both. Very fine clearances go into your injectors and the high-pressure pump, and only the diesel flowing through keeps those surfaces from grinding together.
Poorly at the first, not at all at the second: that is petrol. It is runnier than diesel and strips away the protection your fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the trouble is clear once you put those together. The damage is done by circulation, not by contact. Where the petrol is only inside your tank, it is an issue of fuel, nothing more. Whatever a worn pump sheds travels on, carried by your fuel, into your injectors downstream, which is why a pump that has been working on that petrol is where a mechanical issue begins.
Four scenarios our technicians see around Blendon: how bad is petrol in a diesel?
Fuelled up, not once started. The best case there is. That petrol is in the tank and only the tank, and the task is a drain and a flush where the car stands. This is the one situation that can only really occur on a forecourt, since anywhere else your car has been driven to get there.
Your ignition switched on, or a short start. With the system primed, the lines and filter now hold petrol that has come from the tank. Still usually straightforward: drain, flush, and your filter seen to.
A couple of miles driven, and the pump has spent every one of them running on diluted fuel. The work is your tank, your lines, the fuel filter and clean fuel through the whole circuit, and how hard the vehicle was driven matters as much as how far. Driving the children to Hurst Primary School is one kind of trip. Any miles on the M20, under 5 miles from Blendon, means your engine working hard throughout, and a run to London, under 15 miles away, makes a very different task too.
Driven till it complained. Rattling, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and the motor is telling you. Stop where you are — on the verge on Cedar Grove, at the kerb, down a side road — and do not move it. Lasting damage is very rare when a vehicle is pulled over soon, and the drain and flush-through that still come first sort it out.
Myths Blendon drivers hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a fuller tank of the same mixture. That guidance supposes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through more precise parts: that is how a current diesel moves its fuel, and so the protection matters more, not less.
One myth that catches motorists out: if it starts and drives, it must be unharmed. Any petrol engine fed diesel generally will not run, and so the driver stops and the damage stops with them. Feed petrol to a diesel and it generally starts, idles and pulls away as if nothing has happened — all while its pump is wearing. Being able to run is not proof of being fine.
Myth: "Add some two-stroke oil and drive it home." It is an old fix for a separate fault. What petrol has weakened remains weakened, and that petrol remains in that tank regardless.
Myth: "Drain your tank yourself and you're sorted." After your engine has been run, some of that petrol is no longer inside that tank: it is in your filter and the fuel lines, and it goes right back through your pump on the next start. It is also genuinely risky to drain petrol into a can by the kerbside.
Petrol in a diesel: how does it happen?
No one does it on purpose, and it is rarely carelessness. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol vehicle. That is how the forecourt makes it simple.
It happens when habit and the car stop matching. Any motor that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A hurried fill on the way to Albany Park with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a driver accustomed to petrol: exactly when it occurs. Add a back seat full of kids, a phone call or rain, and the hand takes over.
How to prevent petrol in a diesel on your next fill-up in Blendon
- A green handle for unleaded and black for diesel is usual in the UK — but not on each forecourt. Trust the label on the pump, not the colour.
- Check your filler flap. Many cars state the fuel type inside the flap or on the cap. Look at it on the first fill in a vehicle you do not know.
- One of each in the household? Mark your key to your diesel — a coloured fob, a sticker — since 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. Silly, yes, but it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop reading the petrol pump.
- Less petrol means a thinner mix, and so stop the moment you realise — while remembering that your next stage is unchanged. It's still not to crank it.
Petrol already in a diesel in Blendon? Begin here
The order of things is brief, then. Don't crank it, and don't switch your ignition on. Ask the attendants to help you roll it away from the petrol pump if you're still on the forecourt, whether that's Shell or anywhere else. Call 0333 366 0103 next, with three facts — your fuel, the approximate amount, and whether it's run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different fault — Blendon has a page all for it.
Why one petrol in a diesel task in Blendon costs more than another
There's no honest single quote for this, since the four situations above are four separate jobs. The situation itself does most of the work of moving the cost. The proportion counts next, meaning how much of your tank is petrol, and then the position of the vehicle and whether getting to it is safe for a van.
Ahead of any quote, not after, we ask three queries: the fuel that got in, the quantity, and whether it has run. That is why. A range becomes a straight figure once those answers are in.
About Blendon, for a moment
Blendon is a suburban area in southeast London, situated near the River Thames at an elevation of around 34 metres. Blendon lies approximately 11.6 miles from central London and is close to nearby places such as Crook Log, Blackfen, and Lamorbey. Blendon has a population of around 7095 people and is characterised by predominantly semi-detached housing.
Blendon and Greater London: where our fuel drain cover reaches
Petrol in diesel calls in Blendon — part of the DA postcode area — go to teams that likewise cover the places about it, Crook Log, Blackfen and Lamorbey among them. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
At the petrol pump in Blendon, still?
Then, you could not be in a better place. Turned off it stays; then call.