Wythenshawe: Petrol in a Diesel Car? How Worried to Be
Far less than you probably are, provided it hasn't been started. Everyone in Wythenshawe starts with "have I wrecked it?", and the fair answer is generally no: petrol left inside that tank of any diesel stays harmless until priming, cranking or driving draws it into the fuel system. Petrol in Diesel is who to ring, with your motor left off, so it remains that way. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
What petrol in a diesel does to the engine
Diesel has two tasks on its way through a motor. Before it combusts, it lubricates — and then it ignites. Extremely fine tolerances are built into the injectors and your high-pressure pump, and only the diesel flowing through stops their surfaces grinding together.
Of these two jobs, petrol manages the first badly and the second not at all. It is thinner than diesel and strips away the protection your fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Combined, those make the shape of the problem plain. Contact doesn't do the harm — circulation does. Where the petrol is only in the tank, it's a problem of fuel, nothing more. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Wythenshawe, petrol in a diesel: four situations, from mild to serious
Filled but never started — the best it gets. The petrol is in the tank and just your 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 at a forecourt, because anywhere else your car has been driven to get there.
Ignition on, or started for a second. The system has been primed, so petrol has left that tank and got to the fuel filter and the fuel lines. Still normally easy: drain, flush, and the fuel filter dealt with.
Your pump now spent a couple of miles on diluted fuel — that is what driving it meant. The work is your tank, the lines, the fuel filter and fresh fuel through the whole circuit, and how hard the car was driven counts as much as how far. Short trips, like the school run to Benchill Primary School, are one matter. Getting as far as Manchester, under 10 miles away, makes a very different task — as does any mileage on the M56, under a mile from Wythenshawe, with your engine running hard the whole time.
Rattling, a ragged idle, smoke, a throttle gone soft: driven till it complained. The fuel isn't behaving like diesel any more, and your motor is telling you. Pull up wherever you are — the verge on Hollyhedge Road, a lay-by, a side street — and leave it where it is. What comes first is still the fuel drain and flush, and that sorts it out, with permanent damage very uncommon when a vehicle is pulled over early.
Petrol in a diesel stories Wythenshawe drivers hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — your tank just holds more of the same mixture. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance supposes.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." A newer diesel sends its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools drivers. The driver of a petrol engine fed diesel usually stops, since it will not run, and the harm stops with them. While your pump wears, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Running does not mean fine.
Myth: a two-stroke additive lets you to drive home. It is an old fix, supposed for another problem. What petrol has thinned remains diluted, and the petrol stays in that tank anyway.
The next start draws petrol back round the pump from the fuel lines and your filter, where some of it sits once the engine has run. That's why draining the tank yourself doesn't sort it — a myth. On top of that, petrol cleared into a can by the road is truly dangerous.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle generally will not fit a petrol motor, yet the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and only in that direction.
The moment routine stops matching the car is the moment it happens. A new vehicle, a hire car or a courtesy car. Two motors on one drive, one petrol, one diesel. Your normal forecourt, its pumps now in a different order. Fuelling up in a hurry on the way to Gatley, with a train to catch. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. With rain, a call coming in, or children to deal with, your hand just does what it always has.
Wythenshawe people: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust the label on the pump, not the colour.
- In a car you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of vehicles print the fuel type there.
- One of each in the home? Mark the key to the diesel — a coloured fob, a sticker — since intending to remember isn't enough.
- It seems silly and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- 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.
- Add-on devices are available for cars without one, and some diesels are built with a filler that will not accept a petrol nozzle. Helpful — but a backstop only, never a reason to stop checking the label.
- Stop the moment you realise. Less petrol inside that tank means a weaker blend. It does not change what to do next, which is still not to crank it.
Put petrol in a diesel around Wythenshawe already?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. The attendants at the forecourt — whether at BP itself or wherever you filled up — will normally help roll it away from the pump if you ask. What was put in, roughly how much, and if it has run: tell us those when you phone 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Wythenshawe has a page just for it.
Wythenshawe petrol in a diesel jobs: why one costs more than another
There's no fair single price for this, because the four situations above are four separate jobs. The scenario itself does most of the work of moving the cost. The ratio matters next, meaning how much of that tank is petrol, followed by the location of the car and whether getting to it is safe for a technician.
That is why our engineers ask three queries before quoting instead of after: what was put in, how much, and whether it's run. Those replies are what change a range into one firm number.
About Wythenshawe, briefly
Wythenshawe is a locality in Greater Manchester, situated near the River Mersey at an elevation of around 52 metres. Wythenshawe lies approximately 6 miles south of Manchester city centre and is surrounded by other nearby places such as Benchill, Newall Green, and Sharston. Wythenshawe has a population of around 4386 people and is characterised by its predominantly semi-detached housing stock.
Fuel drain cover around Wythenshawe and across Greater Manchester
Petrol in diesel calls in Wythenshawe — part of the M postcode area — go to teams that also cover the locations about it, Benchill, Newall Green and Sharston included. You need not move your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
Still at the petrol pump in Wythenshawe?
The best spot there is, then — that is where you are. Leave the car turned off, then ring.