Petrol in a Diesel Car in Marple Bridge: How Worried Should You Be?
Probably less than you already are — provided no one has started the car. "Have I ruined it?" is the first question everyone in Marple Bridge asks, and the truthful answer is usually no, since petrol resting in a diesel tank hurts nothing till it is dragged through the system — by ignition priming, by the starter, or by being driven. Leave your engine off then phone Petrol in Diesel — that keeps it like that. 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 don't repeat it.
The engine and petrol in a diesel: what goes on
Diesel does two jobs on its way through an engine. Lubricating comes before burning; it does both. What keeps the surfaces inside your high-pressure pump and your injectors from wearing against each other is your diesel passing through them — they are made to very fine clearances.
Badly at the first, not at all at the second: that is petrol. The knocking comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection the fuel system rests on, and any pump running on that mixture is wearing itself.
The shape of the issue is plain when you put those together. The harm is done by movement, not by contact. A tank with petrol in it is a fuel fault. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors beyond it.
Marple Bridge, petrol in a diesel: four situations, from mild to significant
The best case there is: filled up, not once started. The petrol is inside that tank and just the tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only really take place at a forecourt, as anywhere else the vehicle has been driven to get there.
The ignition turned on, or a brief start. Petrol has left your tank and got to the filter and the fuel lines, because the fuel system has been bled. Still generally easy: drain, flush, and the fuel filter sorted.
A couple of miles driven, and your pump has spent each of them running on thinned fuel. Mileage is only half of it; how hard it was driven matters equally. Either way this work runs to the tank, your lines, your filter and fresh fuel through the entire system. A school run to St Mary's Catholic Voluntary Academy is one matter. Getting as far as Manchester, under 10 miles away, makes a very different job — as does any miles on the M60, under 5 miles from Marple Bridge, with the motor working hard all the way.
Driven on until it complained — knocking, smoke, an uneven idle, a dead throttle. The motor is telling you the fuel is no longer behaving like diesel. Whether it is the verge on Town Street, a lay-by or a side street, stop where you are and leave it. What comes first is still the fuel drain and flush, and that sorts it out, with long-term damage very unusual if a vehicle is pulled over early.
What Marple Bridge people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. Percentage isn't how a diesel fuel system tolerates petrol, however much that advice presumes.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." A current diesel runs its fuel through finer components at higher pressure, which makes the protection matter more, not less.
"It starts, it drives, so there is no harm" — the myth that trips up more motorists than any other. The driver of a petrol motor fed diesel normally has no choice but to stop, because it will not run, and the damage stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile the pump wears. Fine and running aren't the same at all.
An old workaround for a separate fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol weakened gets put back by it — and later, that tank still contains the petrol.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the filter and lines, waiting to go right back through your pump at your next start. And, a can of petrol filled by the kerbside is genuinely dangerous.
How petrol ends up: petrol in a diesel
Carelessness is seldom the cause, and no one means to do it. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
Habit and your car falling out of step is when it occurs. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. Your normal forecourt, its pumps now in a different order. A train to catch, and a hurried fill on the way to Marple. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up in Marple Bridge: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what matters.
- Inspect the filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in any motor you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a home has one of each. So label it.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Tuck the 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 designed to block a petrol nozzle, and add-on devices exist for motors without one. They are a backstop, not a reason to stop reading the pump.
- Less petrol means a weaker mix, and so stop as soon as you realise — though remembering that your next step is unchanged. It's still not to crank it.
Marple Bridge: already put petrol in a diesel?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. If you are still on the forecourt — Shell or anywhere else — ask the staff to help you roll the car away from the petrol pump. Ring 0333 366 0103 next, with three facts — the fuel, the rough quantity, and whether it's run.
Corrosion and deposits are the issue with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and see its own Marple Bridge page.
Why one petrol in a diesel task around Marple Bridge costs more than another
The four situations above are four separate jobs, so no single price for this would be fair. Chiefly, the cost moves with which situation you are in. The ratio counts next, meaning how much of your tank is petrol, and then the location of the vehicle and whether getting to it is safe for a technician.
Before any quote, not after, we ask three queries: the fuel that went in, the amount, and whether it has run. That is why. Their replies are what turn a range into one firm number.
About Marple Bridge and where it is
Marple Bridge is a village situated on the River Goyt in Greater Manchester, with a mix of rural and suburban characteristics. Marple Bridge sits at an elevation of 87 metres, near the town of Marple and other local areas such as Cote Green and Ley Hey Park. Marple Bridge is located approximately 9.5 miles from Manchester, making it a commuter-friendly location. Marple Bridge has a population of around 1589 people, predominantly living in detached housing.
Marple Bridge and Greater Manchester: where our fuel drain cover runs
Marple Bridge sits in the SK postcode area, and our teams that answer petrol in diesel calls there work the locations around it as well — Marple, Cote Green and Ley Hey Park among them. You need not move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
Marple Bridge: still at the pump?
Then, you couldn't be in a better place. Keep it off. Phone.