Petrol in a Diesel Car in Pontrhydyrun: How Worried Should You Be?
Unstarted? Then less anxious than you likely are. Petrol sitting in a diesel tank does nothing to the motor till something pulls it through the system — the ignition priming your pump, the starter, or the drive itself. So the truthful answer to the first query anyone in Pontrhydyrun asks, "have I wrecked it?", is generally no. Keep it that way: leave your engine off and call Petrol in Diesel. What petrol really does to a diesel, how to judge how far it has gone, and how to stop it from happening again: that's the remainder of this page.
Petrol in a diesel: what does it do to your engine?
On its way through a motor, diesel does two tasks. Before it ignites, it lubricates — then it combusts. Extremely fine tolerances go into your injectors and your high-pressure pump, and just your diesel running through keeps their surfaces from grinding together.
The second job petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump on the blend wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the knocking.
Together, those leave the shape of the problem plain. Contact doesn't do the harm — movement does. Petrol in the tank is a fuel problem. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with your fuel to your injectors further on.
Four situations our technicians see in Pontrhydyrun: how bad is petrol in a diesel?
Fuelled, and not started: no case is better. The petrol is in your tank and only that tank, and the job is a drain and a flush where your car sits. This is the one situation that can only truly take place on a forecourt, since anywhere else your car has been driven to get there.
The ignition switched on, or a brief start. Once primed, the system has drawn petrol out of the tank as far as your filter and the fuel lines. Normally little more than clearing, cleaning and seeing to your filter, and so still straightforward.
Those few miles on the road were your pump running on fuel diluted by petrol throughout. How hard the vehicle was driven matters as much as how far, and this work covers that tank, your lines, the fuel filter and clean fuel through the whole circuit. The school run to the local primary school is one matter. Driving as far as Newport, under 10 miles away, makes a very different task — as does any mileage on the M4, under 5 miles from Pontrhydyrun, with your engine running hard all the way.
Driven on till it protested — knocking, smoke, a ragged idle, a dead throttle. What you are hearing is the motor signalling fuel that no longer runs like diesel. Stop where you are — on the verge on A4051, at the kerb, down a side road — and do not move it again. The fuel drain and flush-through still go first, and they take care of it: if a vehicle is pulled over quickly, long-term damage is very unusual.
Pontrhydyrun motorists and the petrol in a diesel myths 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. That advice supposes a diesel fuel system tolerates petrol by percentage. It doesn't.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. Smaller parts and higher pressure are the way a current diesel runs its fuel, and that makes the protection count more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more people than any other. A petrol engine fed diesel normally won't run, so the driver stops and the harm stops with them. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, while the pump wears. Being able to run is not the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different problem. What petrol has diluted remains weakened, and that petrol remains in that tank regardless.
If your engine has run, part of the petrol sits in your filter and the lines, not your tank — and your next start pulls it right back through the pump. So the myth "drain the tank yourself and you are sorted" does not stand up. Draining petrol into a can by the roadside is also really dangerous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally will not go into a petrol motor at all. So the mistake runs one way.
The moment routine stops matching your car is the moment it takes place. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps laid out differently. Filling up in a hurry on the way to Cwmbran, with a train to catch. Exactly the moment it occurs: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Throw in a back seat full of kids, a phone call or rain, and habit takes over.
How to avoid petrol in a diesel at your next fill-up in Pontrhydyrun
- The label is what counts, and so check the petrol pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- Plenty of cars state the fuel inside your filler flap or on the cap, so check there on your first fill in a motor you do not know.
- Mark your key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the petrol pump.
- Some diesels have a filler designed to block a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- As soon as you realise, stop: less petrol in the tank means a thinner blend. What to do next doesn't change, though — still don't crank it.
Already put petrol in a diesel around Pontrhydyrun?
The order of things is brief, then. Leave it unstarted, with the ignition switched off too. If you're still on the forecourt — Texaco or anywhere else — ask the staff to help you roll it clear of the pump. Then phone 0333 366 0103 and tell us what was put in, about how much, and whether it's run.
If it was AdBlue rather than petrol, say so. That is a different fault — corrosion and deposits and not lost lubrication — and it has its own page for Pontrhydyrun.
One petrol in a diesel job around Pontrhydyrun costs more than another. Why?
The four situations above are four separate jobs, so no single price for this would be honest. Mostly, the cost moves with which situation you are in. Beyond that it's the share — how much petrol was put in against how much your tank takes — and then where the car is and whether a van can reach it safely.
Three queries come first, before any quote, rather than after — what was put in, how much, has it run — and that is the reason. With those replies, you get a straight figure instead of a range.
About Pontrhydyrun itself
Pontrhydyrun is a suburban area in Torfaen, situated on the banks of a river at an elevation of 79 metres, with terraced housing being the predominant type of accommodation. Pontrhydyrun lies approximately 5.6 miles from Newport and is part of the wider urban area surrounding the city. Pontrhydyrun is close to nearby places such as Lowlands, Pontnewydd, and Five Locks, and is home to around 3289 residents. Pontrhydyrun is located in a region with a mix of industrial and natural landscapes, reflecting the complex history of the area.
Fuel drain cover across Torfaen, Pontrhydyrun included
Petrol in diesel calls around Pontrhydyrun — part of the NP postcode area — go to vans that also cover the spots around it, Lowlands, Pontnewydd and Five Locks among them. We drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Pontrhydyrun and still at the petrol pump?
In that case, you could not be in a better place. Keep it off. Call.