Boughrood: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, provided it hasn't been started. Till the ignition primes the pump, your starter turns, or your vehicle is driven, petrol in a diesel tank simply rests there and does nothing. Which makes the truthful reply to the first Boughrood query — "have I ruined it?" — normally no. Keep it that way: leave the motor off and call Petrol in Diesel. Further down, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Two tasks fall to diesel on its route through a motor. It ignites, and before it burns it lubricates. Your high-pressure pump and the fuel injectors are made to extremely fine gaps, and the diesel passing through them is what keeps those surfaces from grinding against one another.
The second job petrol does not do at all, and the first it does badly. It's thinner than diesel and takes away the lubrication the fuel system depends 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 knocking comes from.
Taken together, they show the shape the problem has. The harm is done by circulation, not by contact. Where the petrol is only in the tank, it is a fault of fuel, nothing more. Once your pump has been labouring on that petrol, a mechanical problem has started: whatever is shed by a pump that is grinding travels onward to the injectors with your fuel.
Petrol in a diesel around Boughrood: how serious is it? Four cases
The best case there can be: filled up, never started. That petrol is in your tank and just your tank, and the task is a drain and a flush where the car sits. This is the one situation that can only really occur at a forecourt, because anywhere else your car has been driven to get there.
Started for a moment, or only the ignition on. Petrol has left your tank and reached the filter and your lines, since the system has been bled. That is generally still an easy task — a drain, a flush, and your filter dealt with.
Those few miles on the road were your pump working on fuel weakened by petrol throughout. How hard the vehicle was driven counts as much as how far, and the work takes in your tank, the lines, the filter and fresh fuel through the whole system. Driving the kids to the local primary school is one sort of trip. Very different a second time: a run to Hereford, under 25 miles away, or some distance on the M50, under 50 miles from Boughrood, where your engine kept running hard.
Clattering, a ragged idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the engine signalling fuel that no longer runs like diesel. Pull up wherever you are — the verge on Trem y Coed, a lay-by, a side street — and leave the vehicle where it is. What comes first is still the fuel drain and flush, and that deals with it, with permanent damage very unusual when a vehicle is pulled over quickly.
Petrol in a diesel myths Boughrood motorists hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. A newer diesel runs its fuel through finer parts at higher pressure, which makes the protection matter more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. A petrol motor fed diesel generally will not run, so the driver stops and the harm stops with them. While your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. A running engine does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. What petrol has diluted stays diluted, and that petrol stays in the tank regardless.
"Drain it yourself and you are sorted" — a myth, because after it has been running some petrol lies in the fuel filter and lines, waiting to go right back through your pump on the next start. It's also truly dangerous to drain petrol into a can at the kerbside.
How petrol ends up: petrol in a diesel
A careless moment is rarely the cause, and no one means to do it. A diesel nozzle mostly won't fit a petrol car, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error straightforward, and only in one direction.
It occurs when habit and the vehicle stop matching. Any car that's new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. A familiar forecourt with the pumps in a different order. Racing for a train at Cilmeri and fuelling up en route. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it happens. Add a back seat full of children, a phone call or rain, and the hand takes over.
How to avoid petrol in a diesel on your next fill-up in Boughrood
- The label is what counts, so check the petrol pump rather than the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- Many cars state the fuel type inside your filler flap or on the cap, so check there on the first fill in any motor you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a household has one of each. So label it.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems daft. It works.
- While you are thinking about something else, this is an easy mistake to make — so put the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices are available for vehicles without one. They are a safety net, not a reason to stop reading the petrol pump.
- Spotting it halfway? Stop there and then. A thinner mixture results from less petrol inside your tank, yet the next stage remains the same: do not fire it up.
Boughrood: already put petrol in a diesel?
The order of things is brief, then. Never crank it, and do not turn your ignition on. Ask the staff to help you roll it clear of the pump if you're still at the forecourt, whether that is Asda or anywhere else. Call 0333 366 0103 next, with three facts — your fuel, the approximate volume, and whether it's run.
Say so if it was AdBlue rather than petrol: it's a separate problem, with its own page for Boughrood, since AdBlue brings corrosion and deposits instead of lost protection.
What makes one Boughrood petrol in a diesel job cost more than the next
An honest single quote does not exist here: four situations, four separate jobs. What moves your cost is mostly which of them you are in. Two things follow that: the petrol that was put in as a proportion of what the tank takes, then the spot your car is in and whether a technician can get to it safely.
Ahead of any quote, not after, we ask three queries: your fuel that got in, its amount, and whether it's run. That is why. Their answers are what turn a range into one firm number.
About Boughrood itself
Boughrood is a village situated on the banks of the River Wye in Powys, Wales, with a mix of detached housing and rural scenery. Boughrood sits at an elevation of 96 metres, surrounded by rolling hills and countryside. Boughrood is located near the English border, approximately 23 miles from Hereford and 139 miles from London. Boughrood has a population of around 651 residents, living in a predominantly rural setting.
Across Powys and in Boughrood: fuel drain cover
Boughrood rests in the LD postcode area, and our teams that answer petrol in diesel jobs there work the spots near it as well — Llyswen, Cwm-bach and Boughrood Brest among them. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our engineers work, and your car doesn't need to come to us.
Still at the petrol pump around Boughrood?
Then, you could not be in a better place. Keep the vehicle turned off, and ring.