Petrol in a Diesel Car in Trallwn: How Worried Should You Be?
Provided it has not been started, you can worry less than you likely are. Till the ignition primes the pump, your starter turns, or the car is driven, petrol in a diesel tank just sits there and does nothing. Which makes the truthful reply to the first Trallwn query — "have I ruined it?" — usually no. To keep the vehicle like that, call Petrol in Diesel and leave your engine switched off. Below, this page sets out what petrol actually does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
Inside the motor: what petrol in a diesel really does
On its way through an engine, diesel does two tasks. Before it combusts, it protects — then it combusts. Very fine gaps are built into the injectors and the high-pressure fuel pump, and only your diesel running through stops their surfaces grinding together.
Petrol handles the first task poorly and the second not at all. It's thinner than diesel and takes away the lubrication the system rests 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 opposite of what a diesel needs from its fuel. That is where the rattling comes from.
Put those together and the shape of the issue is plain. Contact does not do the harm — movement does. Where that petrol is only in your tank, it's a problem of fuel, nothing more. After your pump has been labouring on that petrol, a mechanical issue has started: whatever is shed by a pump that is wearing down is carried onward to the fuel injectors with your fuel.
Petrol in a diesel in Trallwn: how bad is it? Four situations
Fuelled up, never started. The best case there is. That petrol is inside the tank and just the tank, and the task is a drain and a flush where the car sits. This is the one situation that can only really happen at a forecourt, because anywhere else the vehicle has been driven to get there.
A moment's running, or just your ignition on. The fuel system has been bled, so petrol has left your tank and got to the fuel filter and your lines. Drain, flush, deal with the fuel filter: still normally simple.
The pump has worked a few miles on weakened fuel — that is what driving it meant. Tank, lines, filter, then fresh fuel put through the entire system: that is the work, and the way your car was driven counts as much as the distance. Driving the kids to the local primary school is one sort of trip. Getting as far as Swansea, under 5 miles away, makes a very different task — as does any mileage on the M4, under a mile from Trallwn, with the engine working hard all the way.
Driven until it complained. Rattling, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and the engine is saying so. Stop wherever you are — the verge on Tyn y Waun, a lay-by, a side street — and leave the vehicle where it is. A car stopped early very rarely has permanent damage, because the drain and the flush, which still go first, deal with it.
Myths Trallwn drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. A bigger tank of the same mix is all you get, because topping up takes out nothing. The idea behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and nearer the opposite. Smaller parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication count more, not less.
One myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally will not run, and so the driver stops — and the harm stops with them. Feed petrol to a diesel and it generally starts, ticks over and drives away as if nothing has happened — all the while its pump wears. Being able to run isn't the same as being fine.
An outdated fix for a separate problem is behind this one. Myth: "Add some two-stroke oil and drive it home." The petrol is still inside the tank after that, and what it has weakened is not put back.
If the engine has been run, part of that petrol sits in the fuel filter and the fuel lines, not your tank — and your next start sends it right back through your pump. So the myth "drain that tank yourself and you are sorted" does not hold. Clearing petrol into a can by the roadside is also really risky.
Why petrol in a diesel takes place at all
A careless moment is rarely the cause, and no one means to do it. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol car. That's how the forecourt makes it easy.
Routine and your car getting out of step is when it happens. Any motor that's new to you — hired, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps laid out differently. A train to catch, and a rushed fill en route to Llansamlet. Exactly the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. Add a back seat full of kids, a phone call or rain, and the hand takes over.
Trallwn motorists: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is usual in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- The first fill in a strange vehicle is the time to check the filler flap — on it, or on the cap, many motors state the fuel to use.
- One of each in the house? Label your key to your diesel — a bright fob, a sticker — since intending to remember isn't enough.
- It sounds silly and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- While you're thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices exist for vehicles without one, and some diesels are built with a filler that will not take a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol in the tank makes a weaker mix. What to do next doesn't change, though — still do not crank it.
Petrol already in a diesel around Trallwn? Begin here
Short and simple, then, is the order of things. Leave it unstarted, with your ignition off as well. If you're still on the forecourt — Texaco or anywhere else — ask the staff to help you roll it away from the petrol pump. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That is a separate fault — corrosion and deposits instead of lost protection — and it has its own page for Trallwn.
Trallwn petrol in a diesel jobs: why one costs more than another
The four situations above are four different tasks, so no single quote for this would be honest. Chiefly, the cost moves with which one you're in. Two things follow that: the petrol that went 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.
What went in, how much, and whether it's run — three questions our engineers ask before pricing, not after, for precisely that reason. Those answers are what change a range into one firm number.
About Trallwn, briefly
Trallwn is a suburban area located on the outskirts of Swansea, situated near the coast in southern Wales. Trallwn sits at an elevation of 68 metres, overlooking the surrounding landscape. Trallwn is characterized by its predominantly semi-detached housing stock, with nearby neighbourhoods including Pentre-dwr and Winsh-wen. Trallwn is close to the city of Swansea, being only 3.2 miles away.
Fuel drain cover across Swansea, Trallwn included
Trallwn rests in the SA postcode area, and our vans that answer petrol in diesel calls there work the locations around it as well — Pentre-dwr, Tair-ysgol and Winsh-wen among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations we work, and your vehicle does not need to come to us.
Trallwn: still at the petrol pump?
In that case, you could not be in a better place. Keep it off. Ring.