Should You Worry? Petrol in a Diesel Car in Wood Hayes
Less than you likely are, if it hasn't been started. Everyone around Wood Hayes starts with "have I ruined it?", and the fair answer is generally no: petrol resting inside your tank of a diesel remains harmless until priming, cranking or driving draws it into the fuel system. Petrol in Diesel is who to phone, with the motor kept off, so it stays that way. Keep reading for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and the way to make sure you never repeat it.
Petrol in a diesel: what does it do to the engine?
On its way through an engine, diesel has two tasks. Oiling comes before burning; it does both. What stops the surfaces inside the high-pressure fuel pump and the injectors from wearing against each other is your diesel passing through them — they are built to very fine tolerances.
Petrol handles the first task badly and the second not at all. It's thinner than diesel and removes the protection the fuel system hinges on, and so a pump running on a petrol blend 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 knocking comes from.
The shape of the problem is clear when you put those together. Not contact but circulation is what causes the harm. Where that petrol is only inside the tank, it is a fault of fuel, nothing more. Once your pump has been running on that petrol, a mechanical fault has begun: anything shed by a pump that is wearing down travels downstream to your injectors with the fuel.
Wood Hayes, petrol in a diesel: four situations, from mild to major
Fuelled up, never started. The best case there can be. On a forecourt, and truly only there, the petrol is still limited to your tank — since everywhere else the vehicle was driven to get to it. The task is draining and purging on the spot.
A moment's running, or just your ignition on. With the fuel system primed, the lines and filter now contain petrol that has come from that tank. Usually little more than draining, purging and sorting the fuel filter, and so still straightforward.
Driven a couple of miles. Now your pump has spent these miles working on thinned fuel. Tank, lines, filter, then fresh fuel put through the whole circuit: that's the work, and the way the vehicle was driven matters as much as the mileage. Driving the children to Long Knowle Primary School is one sort of trip. Any mileage on the M54, under 3 miles from Wood Hayes, means the engine working hard throughout, and a run to Wolverhampton, under 3 miles away, is a very different task as well.
Clattering, a ragged idle, smoke, a throttle gone soft: driven until it complained. The engine is telling you your fuel is no longer behaving like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Blackhalve Lane. What comes first is still the drain and flush-through, and that deals with it, with long-term damage very rare if a car is pulled over early.
What Wood Hayes people get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing comes out when you top up — the tank just carries more of the same mixture. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and nearer the opposite. A modern diesel sends its fuel through finer parts at higher pressure, which makes the lubrication count more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more motorists than any other. The driver of a petrol engine fed diesel normally has no choice but to stop, since it will not run, and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Being able to run isn't proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. What petrol has thinned stays diluted, and the petrol stays in the tank regardless.
The next start draws petrol back round the pump out of the lines and the fuel filter, where some of that sits once your engine has run. That is why a DIY tank drain does not sort it — a myth. Besides, petrol emptied into a can by the road is truly dangerous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol vehicle at all. So the slip runs one way.
When habit and the vehicle stop matching, it takes place. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A train to catch, and a rushed fill on the way to Wolverhampton. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you at the forecourt for its first tank — that's when. Throw in rain, a phone call or a back seat full of children, and your hand does what it has always done.
Next time you fill up in Wood Hayes: preventing petrol in a diesel
- The label is what counts, so read the petrol pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before your first fill: many vehicles print the fuel type there.
- Mark the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Tuck your phone away. This is an easy mistake to make whilst you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to block a petrol nozzle, and add-on devices are available for vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Spotting it mid-fill? Stop at once. A thinner mixture results from less petrol inside your tank, yet the next step stays the same: don't start the car.
Already put petrol in a diesel around Wood Hayes?
Short and simple, then, is the order of things. Don't start the vehicle, and do not switch your ignition on. Yet at the forecourt, at JET or anywhere else? Ask the attendants to help you push the vehicle clear of the pump. Call 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and if it has run.
Say so if it was AdBlue instead of petrol: it is a different fault, with its own page for Wood Hayes, because AdBlue brings corrosion and deposits rather than lost lubrication.
Wood Hayes petrol in a diesel jobs: why one costs more than another
There is no fair single price for this, because the four situations above are four separate jobs. What moves your cost is chiefly which of them you are in. After that it's the proportion — how much petrol was put in against how much that tank takes — and then where the car is and whether our van can get to it safely.
Three queries come first, before quoting, rather than after — what got in, how much, has it run — and that is the reason. Those answers are what turn a range into one firm number.
About Wood Hayes itself
Wood Hayes is a suburban area located near Wolverhampton in the West Midlands, sitting at an elevation of around 148 metres. Wood Hayes forms part of the larger Wolverhampton urban area, with nearby places including Scotlands, Westcroft, and Bushbury Hill. Wood Hayes has a population of approximately 5381 people, predominantly living in semi-detached housing.
Fuel drain cover around Wood Hayes and across West Midlands
Our vans answering petrol in diesel calls in Wood Hayes, in the WV postcode area, equally work the spots near it, Scotlands, Westcroft and Bushbury Hill among them. Our technicians drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Wood Hayes and still at the petrol pump?
Then you're in the best place there is. Keep it switched off, then ring.