How Worried Should You Be? Petrol in a Diesel Car in Harmondsworth
Less than you probably are, provided it hasn't been started. Everyone around Harmondsworth begins with "have I ruined it?", and the honest answer is usually no: petrol left in the tank of any diesel stays harmless until priming, cranking or driving pulls it into the system. To keep it like that, call Petrol in Diesel and leave the motor alone. Further down, you will find what petrol really does inside a diesel, how far it might have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the engine?
Diesel has two jobs on its way through an engine. Before it ignites, it lubricates — then it combusts. Made to extremely fine tolerances, the fuel injectors and the pump rely on the diesel moving through them to stop their surfaces wearing against one another.
Poorly at the first, not at all at the second: that's petrol. It's thinner than diesel and strips away the lubrication the system rests on, and 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.
Put these together and the shape of the problem is plain. Not contact but circulation is what does the harm. Where the petrol is only in your tank, it's an issue of fuel, nothing more. Once your pump has been working on that petrol, a mechanical problem has begun: anything shed by a pump that is wearing down is carried onward to the injectors with your fuel.
Harmondsworth, petrol in a diesel: four situations, from mild to serious
Fuelled but never started — the best it gets. At a forecourt, and truly only there, that petrol is still limited to your tank — because anywhere else your car was driven to get to it. The job is emptying and flushing on the spot.
Started for a second, or only your ignition on. Petrol has come out of the tank and got to the fuel filter and your lines, because the system has been bled. Drain, flush, see to the fuel filter: still usually easy.
The pump has worked a few miles on weakened fuel — that is what driving the vehicle does. How hard the vehicle was driven counts as much as how far, and this work takes in that tank, the fuel lines, your filter and fresh fuel through the whole system. A school run to Harmondsworth Primary School is one thing. Any mileage on the M4, under a mile from Harmondsworth, means your engine working hard throughout, and a run to Westminster, under 25 miles away, is a very different job as well.
Driven until it protested. Clattering, a ragged idle, smoke, a throttle that has gone soft. The engine is telling you your fuel is no longer behaving like diesel. Leave it wherever it stops: a lay-by, a quiet street, the verge on High Street. The fuel drain and flush-through still go first, and they sort it out: if a vehicle is pulled over quickly, lasting damage is very uncommon.
Petrol in a diesel myths Harmondsworth motorists hear
False: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mixture is all you get, since topping up removes nothing. A diesel fuel system doesn't accept petrol by percentage in the way that guidance presumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. A current diesel sends its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
"It starts, it drives, so there is no harm" — the myth that catches most people than any other. The motorist of a petrol engine fed diesel usually stops, since it will not run, and the damage stops there. While the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Fine and running are not the same at all.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. None of what petrol diluted gets put back by it — and afterwards, that tank still holds that petrol.
Myth: "Drain the tank yourself and you are sorted." Once the engine has run, some of the petrol is no longer in that tank: it's in the fuel filter and the fuel lines, and it goes straight back through your pump on the next start. And, a can of petrol filled at the roadside is genuinely hazardous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it easy, and the mistake runs one way.
The moment routine stops matching the car is the moment it happens. Courtesy car, hire car, or a car that is new. A household with one petrol and one diesel on the drive. A familiar forecourt with the pumps in a different order. A hurried fill en route to Heathrow Terminal 5 Rail with a train to catch. Years of petrol motors behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done.
Harmondsworth people: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Check the filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in a motor you don't know.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a home has one of each. So label it.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump.
- Tuck your phone away. This is an easy mistake to make while you are thinking about something else.
- Add-on devices are available for motors without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a backstop only, never a reason to stop checking the label.
- Less petrol makes a thinner blend, and so stop the moment you notice — though remembering that the next step is unchanged. It is still not to fire it up.
Harmondsworth: already put petrol in a diesel?
In that case, there's only a short order of things. Do not crank it, and don't switch your ignition on. If you're still on the forecourt — Shell or anywhere else — ask the staff to help you roll it away from the pump. What went in, about how much, and whether it's run: tell us that when you call 0333 366 0103.
Corrosion and deposits form the problem with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Harmondsworth page.
Harmondsworth petrol in a diesel jobs: why one costs more than another
The four situations above are four separate jobs, so no single quote for this would be honest. The scenario itself does most of the work of moving your cost. Where the vehicle is matters too, and whether our van can safely get to it, after the ratio of petrol to what the tank holds.
Ahead of any quote, not after, come three queries: the fuel that went in, its amount, and if it has run. That is why. A range turns into a straight figure when the answers are in.
About Harmondsworth and where it is
Harmondsworth is a suburban area in the London Borough of Hillingdon, situated on the River Colne at an elevation of around 28 metres. Harmondsworth lies near the villages of Longford, Sipson, and West Drayton, and is approximately 15 miles west of central London. Harmondsworth is characterised by its semi-detached housing stock and quiet residential atmosphere. Harmondsworth has a population of around 1161 people, according to recent estimates.
Fuel drain cover around Harmondsworth and across Greater London
Our vans answering petrol in diesel calls around Harmondsworth, in the UB postcode area, also work the spots near it, Longford, Sipson and West Drayton included. We drain where your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the petrol pump in Harmondsworth, still?
Nothing beats it: that is where you now are. Turned off it stays; then phone.