Petrol in a Diesel Car in Ballynahinch: How Worried Should You Be?
Less than you likely are, provided it hasn't been started. Everyone in Ballynahinch begins with "have I ruined it?", and the honest answer is normally no: petrol left in your tank of any diesel stays harmless till priming, cranking or driving pulls it into your fuel system. To leave the vehicle that way, call Petrol in Diesel then leave your motor switched off. The rest of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Your engine and petrol in a diesel: what goes on
Diesel does two jobs on its way through a motor. It burns, and before it burns it lubricates. The high-pressure fuel pump and your injectors are built to extremely fine gaps, and the diesel passing through them is what keeps those surfaces from wearing down against each other.
The second task petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump on the mixture wearing itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the knocking.
Put those together and the shape of the problem is plain. The harm is done by movement, not by contact. Where that petrol is only in the tank, it is an issue of fuel, nothing more. Once the pump has been running on that petrol, a mechanical problem has begun: whatever is shed by a pump that's wearing down travels downstream to the injectors with the fuel.
Ballynahinch, petrol in a diesel: four cases, from mild to significant
Filled up, never 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 the petrol kept in that tank alone, it's drained and cleaned on the spot, and nothing more is needed.
Started for a second, or only your ignition on. Petrol has come out of that tank and reached the filter and the fuel lines, because the fuel system has been bled. Drain, flush, deal with your filter: still usually simple.
Those few miles on the road were your pump working on fuel weakened by petrol throughout. Tank, lines, filter, then fresh fuel put through the entire system: that's this work, and the way the car was driven counts as much as the mileage. Short trips, like the school run to the local primary school, are one matter. Getting as far as Lisburn, under 15 miles away, makes a very different task — as does any mileage on the M77, over 50 miles from Ballynahinch, with the motor working hard the whole time.
Driven until it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is your engine reporting fuel that no longer runs like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on South Crescent. Long-term damage is very unusual if a car is stopped quickly, and the drain and flush that still go first sort it out.
Ballynahinch motorists and the petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, however much that guidance presumes.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." Finer components and higher pressure are the way a newer diesel runs its fuel, and that makes the protection count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no damage done." The motorist of a petrol motor fed diesel usually stops, because it will not run, and the harm stops with them. Feed petrol to a diesel and it generally starts, idles and pulls away like nothing happened — all while its pump is wearing. A running engine doesn't mean fine.
An outdated fix for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive it home." What petrol has weakened stays diluted, and the petrol stays inside that tank anyway.
Myth: "Drain that tank yourself and you're sorted." Once the motor has been run, some of the petrol is no longer in your tank: it is in your filter and the fuel lines, and it goes straight back through the pump at the next start. Besides, petrol drained into a can by the road is truly dangerous.
Petrol in a diesel: how does it occur?
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it simple, and the error runs one way.
It happens when habit and your car stop matching. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps laid out differently. Filling up in a rush on the way to the nearest station, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: precisely when it takes place. Your hand does what it has always done when you add rain, a phone call or a back seat full of kids.
Ballynahinch motorists: how to avoid petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on every forecourt. The label is what counts.
- In a car you don't know, look inside the flap over the filler or at the cap before your first fill: many cars state the fuel there.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key when a home has one of each. So mark it.
- Before the nozzle comes off the pump the first time you fill a hired or new car, say "diesel" out loud. Silly, yes, yet it does the trick.
- Mistakes like this are simple to make while your mind is on something else, so the phone goes away.
- Add-on devices exist for motors without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol inside the tank means a thinner mix. It does not change what to do next, which is still not to fire it up.
Put petrol in a diesel in Ballynahinch already?
Short and simple, then, is the order of things. Don't turn your ignition on, and do not fire it up. Ask the attendants to help you roll it away from the pump if you are still at the forecourt, whether that's the nearest petrol station or somewhere else. Next, 0333 366 0103. We will ask what got in, about how much, and if it's been run.
Corrosion and deposits form the trouble with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Ballynahinch page.
One petrol in a diesel job in Ballynahinch costs more than another. Why?
Four different jobs lie behind the four scenarios above — which is why there's no honest single price. Mostly, your cost moves with which situation you're in. Two things follow that: the petrol that was put in as a proportion of what your tank takes, then the spot the car is in and whether our van can get to it safely.
Three queries come first, before quoting, rather than after — what went in, how much, has it run — and this is the reason. Their answers are what turn a range into one firm number.
About Ballynahinch
Ballynahinch is a small town in County Down, situated inland at an elevation of 66 metres, approximately 10 miles from Lisburn. Ballynahinch has a population of around 3810 people, with semi-detached housing being the predominant type. Ballynahinch is close to nearby places such as Spa, Drumaness, and Listooder, and is located about 311 miles northwest of London. Ballynahinch sits in a rural area, surrounded by the countryside of Northern Ireland.
Fuel drain cover around Ballynahinch and across County Down
Spa, Drumaness and Listooder are among the spots near Ballynahinch that the same vans work, answering petrol in diesel call-outs across Ballynahinch's BT postcode area. Our engineers drain wherever your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the petrol pump in Ballynahinch, right now?
Then you are in the best spot there can be. Leave the vehicle turned off, then ring.