Pool Meadow: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, you can worry far less than you likely are. "Have I ruined it?" is the first question everyone in Pool Meadow asks, and the truthful answer is normally no, because petrol resting in a diesel tank hurts nothing till it is dragged through the fuel system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to call, with the engine left off, so it stays that way. Below, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
What petrol in a diesel does to your engine
Two tasks fall to diesel on its route through a motor. Before it combusts, it protects — then it burns. The high-pressure pump and the injectors are made to extremely fine clearances, and the diesel passing through them is what stops those surfaces from wearing against one another.
Of those two jobs, petrol handles the first poorly and the second not at all. A pump running on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where the rattling comes.
Put those together and the shape of the issue is plain. It's movement that causes the damage, not contact. A tank with petrol in it is a fuel issue. Whatever a worn pump sheds goes on, borne by your fuel, into the injectors further along, which is why a pump that has worked on that petrol is where a mechanical issue begins.
Four scenarios we see around Pool Meadow: how serious is petrol in a diesel?
Filled but not once started — the best it gets. Only the tank has petrol in it, so the job is emptying your tank and flushing the system where your car stands. This situation can only really take place on a forecourt: anywhere else, the car got there by being driven.
Started for a moment, or just the ignition on. The system has been bled, so petrol has left that tank and reached the filter and your lines. Usually little more than clearing, purging and seeing to the filter, and so still easy.
Those few miles on the road were the pump labouring on fuel thinned by petrol throughout. The work is that tank, your lines, the filter and clean fuel through the entire system, and how hard your car was driven counts as much as how far. The school run to Kingsholm Church of England Primary School is one thing. Driving as far as Gloucester, under a mile away, makes a very different job — as does any miles on the M5, under 5 miles from Pool Meadow, with the motor working hard all the way.
Driven until it complained. Rattling, a lumpy idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer acting like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Westend Terrace. The fuel drain and flush-through still go first, and they sort it out: if a vehicle is pulled over early, permanent damage is very unusual.
Myths Pool Meadow people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. Percentage is not how a diesel fuel system tolerates petrol, however much that guidance supposes.
"Current diesels can handle a little petrol" — a myth, and closer to the reverse. Lubrication counts more on modern diesels, not less, because their fuel runs through finer components at higher pressure.
This is the one that catches drivers. Myth: "If it starts and drives, there is no harm done." A petrol motor fed diesel usually won't run, and so the driver stops and the damage stops with them. Whilst the pump wears, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Fine and running are not the same at all.
An old workaround for a distinct fault is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." The petrol is still in your tank afterwards, and what it has thinned isn't put back.
Myth: "Drain your tank yourself and you're sorted." After the motor has been run, some of that petrol is no longer inside your tank: it's in the fuel filter and your lines, and it goes straight back through your pump on your next start. On top of that, petrol cleared into a can by the road is truly risky.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. One way only, since of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it simple.
When habit and your car stop matching, it occurs. A car that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps arranged differently. Racing for a train outside Gloucester and fuelling up en route. A new-to-you diesel Renault Megane, its first fuelling, and a driver used to petrol: exactly when it occurs. With rain, a call arriving, or a car full of children to deal with, the hand just does what it always has.
Pool Meadow motorists: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Check the pump's label; the colour is just a hint.
- In a motor you do not know, look inside the flap over your filler or at the cap before the first fill: many vehicles print the fuel there.
- One of each in the household? Mark your key to your diesel — a coloured fob, a sticker — because meaning to remember is not enough.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It seems daft. It works.
- Put the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and aftermarket devices are available for the rest. Treat it as a backstop, then keep checking the petrol pump.
- The moment you realise, stop: less petrol in the tank means a thinner blend. What to do next doesn't change, though — still don't start the car.
Petrol already in a diesel in Pool Meadow? Start here
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. Still on the forecourt, at Texaco or anywhere else? Ask the attendants to help you roll it clear of the petrol pump. What got in, roughly how much, and whether it's run: tell us that when you ring 0333 366 0103.
If it was AdBlue rather than petrol, say so. That is a separate problem — corrosion and deposits and not lost lubrication — and it has its own page for Pool Meadow.
Why one petrol in a diesel job in Pool Meadow costs more than another
A fair single price doesn't exist here: four scenarios, four separate jobs. Mostly, your cost moves with which situation you are in. Where the vehicle is counts too, and whether a technician can safely reach it, after the share of petrol to what the tank holds.
What went in, how much, and if it's run — three questions we ask before costing, not after, for precisely that reason. A range turns into a straight figure once the replies are in.
About Pool Meadow, briefly
Pool Meadow is a suburban area located on the outskirts of Gloucester, situated near the river at a low elevation of around 11 metres. Pool Meadow sits in close proximity to the city centre, being only 0.6 miles away, and is near other local areas such as The Island and Over. Pool Meadow is characterized by its predominantly flat-type housing, which is home to a population of approximately 1223 residents.
Across Gloucestershire and in Pool Meadow: fuel drain cover
The vans answering petrol in diesel call-outs around Pool Meadow, in the GL postcode area, equally work the spots near it, The Island, Over and Gloucester among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our technicians drain, and the vehicle doesn't need to come to us.
In Pool Meadow and still at the pump?
In that case, you could not be in a better spot. Ring, and keep it turned off.