Should You Worry? Petrol in a Diesel Car in Prendergast
If it has not been started, worry far less than you probably are. Petrol sitting in a diesel tank does nothing to the motor till something pulls it through your fuel system — your ignition priming your pump, the starter, or driving on its own. So the truthful answer to the first question anyone in Prendergast asks, "have I ruined it?", is usually no. Petrol in Diesel is who to phone, with your engine left off, so it remains that way. Read on for three things: the effect petrol has inside a diesel engine, the clues of how far it has spread, and ways to make sure you never do it again.
Inside the engine: what petrol in a diesel really does
Passing through an engine, diesel does two jobs at once. Lubricating comes before burning; it does both. Extremely fine gaps are built into the injectors and the high-pressure fuel pump, and just the diesel running through stops those surfaces grinding together.
Petrol does the first task poorly and the second not at all. It is runnier than diesel and takes away the protection your fuel system hinges on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the rattling comes from.
The shape of the problem is plain when you put those together. It is movement that causes the damage, not contact. Where that petrol is only inside your tank, it's an issue of fuel, nothing more. The start of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors beyond it.
Prendergast, petrol in a diesel: four situations, from mild to major
Filled up, never started. The best case there is. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol kept in that tank alone, it's cleared and cleaned right where it stands, and nothing more is needed.
Ignition on, or started for a moment. Petrol has come out of the tank and reached your filter and the lines, because your system has been bled. Still generally straightforward: drain, flush, and the fuel filter seen to.
A few miles driven, and the pump has spent each of them running on diluted fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that is the work, and the way the vehicle was driven matters as much as the distance. Short trips, like the school run to the local primary school, are one matter. Very different a second time: a run to St Davids, under 15 miles away, or any mileage on the M4, under 50 miles from Prendergast, where the engine kept working hard.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven until it complained. That's the engine telling you its fuel no longer is behaving like diesel. Whether it's the verge on Prendergast, a lay-by or a side road, stop where you are then leave it. A vehicle stopped early very rarely has long-term damage, as the drain and the flush, which still come first, deal with it.
Petrol in a diesel stories Prendergast motorists hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mix. That advice supposes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. Protection matters more on newer diesels, not less, since their fuel passes through more precise components at higher pressure.
"It starts, it drives, and so there is no harm" — the myth that catches most people than any other. Diesel in a petrol motor usually leaves a motor that will not run: the motorist stops, and so does the damage. Feed petrol to a diesel and it normally starts, ticks over and drives away like nothing has happened — all while its pump wears. Fine and running aren't the same thing.
An outdated workaround for a distinct issue is behind this one. Myth: "Add some two-stroke oil and drive it home." None of what petrol weakened gets put back by it — and afterwards, that tank still contains the petrol.
Myth: "Drain your tank yourself and you are sorted." After the engine has run, some of that petrol is no longer inside that tank: it is in the filter and your lines, and it goes straight back through the pump on your next start. Draining petrol into a can by the roadside is also truly dangerous.
Why petrol in a diesel takes place at all
No one does it on purpose, and it's rarely carelessness. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol car. That's how the forecourt makes it easy.
The moment routine stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a motor that's brand new. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill on the way to Haverfordwest. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Add rain, a phone call or a back seat full of children, and the hand does what it has always done.
Prendergast drivers: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Trust the label on the petrol pump, not the colour.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors print the fuel there.
- Label your key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Mistakes like this are simple to make whilst your mind is on something else, and so your phone goes away.
- Some diesels have a filler built to reject a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- The moment you notice, stop: less petrol in your tank means a weaker mix. What to do next doesn't change, though — still don't crank it.
Put petrol in a diesel in Prendergast already?
Then the order of things is brief. Never start the vehicle, and don't turn your ignition on. Ask the staff to help you push it clear of the petrol pump if you're still at the forecourt, whether that's Morrisons or somewhere else. Next, 0333 366 0103. We will ask what was put in, about how much, and if it's been run.
Corrosion and deposits form the problem with AdBlue, whereas petrol means lost protection. So if it was AdBlue, say so — and see its own Prendergast page.
What makes one Prendergast petrol in a diesel job cost more than the next
Four different tasks lie behind the four situations above — which is why there's no fair single quote. Which of them you are in is chiefly what shifts your cost. Two things follow that: the petrol that was put in as a share of what your tank holds, then the spot your car is in and whether a technician can get to it safely.
Before any quote, not after, come three queries: your fuel that went in, the quantity, and if it's run. That is why. The replies change a range into a straight figure.
About Prendergast itself
Prendergast is a suburban area in Pembrokeshire, situated near the coast of Wales, with an elevation of around 31 metres. Prendergast lies close to the nearby towns of Haverfordwest and St Davids, and is characterized by its predominantly semi-detached housing stock. Prendergast is part of a larger network of communities in the region, including The Marsh and Glanafon.
Prendergast and Pembrokeshire: where our fuel drain cover runs
Prendergast rests in the SA postcode area, and our teams that answer petrol in diesel jobs there work the places around it as well — Haverfordwest, The Marsh and Glanafon among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our technicians work, and the car does not need to come to us.
Prendergast: still at the pump?
No position is better: that is where you are. Turned off it remains; then phone.