How Worried Should You Be? Petrol in a Diesel Car in Queens Park
Likely less than you already are — as long as no one has started the vehicle. Everyone around Queens Park begins with "have I ruined it?", and the fair answer is usually no: petrol resting in that tank of a diesel remains harmless until priming, cranking or driving draws it into the system. Leave your motor off and call Petrol in Diesel — that is how you keep it that way. The remainder of this page explains what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
What petrol in a diesel does to your engine
Diesel has two tasks on its way through an engine. It lubricates to begin with, and only then does it burn. Extremely fine tolerances are built into the injectors and the high-pressure pump, and just your diesel running through keeps those surfaces from grinding together.
The second job petrol does not do at all, and the first it does poorly. It's runnier than diesel and removes the protection the fuel system depends on, and so a pump running on a petrol mix 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 clattering comes from.
Put these together and the shape of the problem is clear. The harm is done by circulation, not by contact. Any tank with petrol in it is a fuel issue. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to your injectors further on.
How bad is petrol in a diesel? Four scenarios our engineers see around Queens Park
Fuelled up, not once started. The best case there can be. Only the tank has petrol in it, and so the job is emptying that tank and flushing the fuel system where the car sits. This situation can only truly take place on a forecourt: anywhere else, the vehicle got there by being driven.
A moment's running, or merely your ignition on. Petrol has come out of your tank and got to the fuel filter and the lines, since the system has been bled. Normally little more than emptying, purging and seeing to the filter, and so still simple.
A few miles driven, and the pump has spent each of them running on weakened fuel. Tank, lines, filter, then clean fuel put through the entire circuit: that's this work, and the way the vehicle was driven matters as much as the mileage. On the school run to St Luke's CofE Primary School, the miles is short. Driving as far as Westminster, under 5 miles away, makes a very different job — as does any mileage on the M1, under 3 miles from Queens Park, with your engine labouring hard all the way.
Knocking, an uneven idle, smoke, a throttle gone soft: driven till it complained. That's your motor telling you its fuel no longer is behaving like diesel. Leave it where it stops: a lay-by, a side street, the verge on Albert Road. A car stopped early very rarely has permanent damage, as the drain and the flush, which still come first, sort it out.
Queens Park people and that petrol in a diesel myths they hear
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. That advice supposes a diesel fuel system tolerates petrol by percentage. It does not.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. At higher pressure, through smaller parts: that's how a modern diesel handles its fuel, and so the lubrication matters for more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more people than any other. The motorist of a petrol engine fed diesel usually stops, because it will not run, and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile your pump wears. Being able to run isn't the same as being fine.
An outdated workaround for a different fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." It does not put back what petrol has diluted, and that petrol is still in the tank later on.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol sits in the fuel filter and lines, ready to go right back through your pump on your next start. Draining petrol into a can at the kerbside is also genuinely dangerous.
How does petrol in a diesel take place?
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
The moment habit stops matching the car is the moment it takes place. Courtesy car, hire car, or a vehicle that is new. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. A train to catch, and a rushed fill on the way to Queens Park (London). The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it happens. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up in Queens Park: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is only a hint.
- The first fill in a strange car is the time to check your filler flap — inside it, or on the cap, many cars state the fuel they take.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So label it.
- 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 seems daft and it does the trick.
- Tuck the phone away. This is an easy mistake to make while you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop reading the pump.
- Noticing it halfway? Stop at once. A thinner blend follows from less petrol inside that tank, yet the next step stays the same: don't crank it.
Queens Park: already put petrol in a diesel?
Then the order of things is short. Starting it is out, and so is switching on your ignition. If you're still on the forecourt — Sainsbury's or anywhere else — ask the attendants to help you roll the vehicle away from the pump. Then ring 0333 366 0103 and tell us what was put in, about how much, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate issue — Queens Park has a page all for it.
One petrol in a diesel task in Queens Park costs more than another. Why?
An honest single price doesn't exist here: four situations, four separate jobs. Which of them you are in is mostly what shifts the cost. After that it's the proportion — how much petrol got in against how much the tank takes — and after that where the car is and whether a van can get to it safely.
Ahead of any quote, not after, we ask three questions: the fuel that was put in, its volume, and if it has run. That is why. A range turns into a straight figure once the replies are in.
About Queens Park, for a moment
Queens Park is a suburban area in northwest London, situated approximately 3.7 miles from the city centre. Queens Park is characterized by its predominantly flat-type housing and sits at an elevation of around 36 metres. Queens Park is close to nearby places such as Kilburn, West Kilburn, and Kensal Rise, and is located near the city of Westminster, which is about 4 miles away. Queens Park has a population of around 24626 people.
Across Greater London and around Queens Park: fuel drain cover
Kilburn, West Kilburn and Kensal Rise are among the locations around Queens Park that the same vans work, answering petrol in diesel calls across Queens Park's NW postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all places we drain, and the vehicle does not need to move to us.
At the pump around Queens Park, still?
Then, you couldn't be in a better position. Call, and leave it switched off.