Petrol in a Diesel Car in Lavenham: How Worried Should You Be?
Less than you probably are, provided it hasn't been started. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through your fuel system — the ignition priming your pump, the starter, or driving itself. So the truthful answer to the first question anyone around Lavenham asks, "have I ruined it?", is usually no. To leave the vehicle like that, call Petrol in Diesel then leave the motor switched off. Below, you will find what petrol actually does inside a diesel, how far it might have gone, and how to stop it happening to you again.
What petrol in a diesel does to the motor
Diesel has two tasks on its way through a motor. It burns, and before it combusts it lubricates. Made to very fine gaps, the injectors and your pump depend on your diesel moving through them to stop their surfaces wearing against one another.
Of these two tasks, petrol handles the first badly and the second never. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on the mixture to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the knocking.
Combined, those leave the shape of the problem clear. Not contact but movement is what does the harm. All a tank with petrol in it amounts to is a fuel issue. The start of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
How serious is petrol in a diesel? Four situations our technicians see around Lavenham
Fuelled up, not once started. The best case there can be. The petrol is inside that tank and just your tank, and the task is a drain and a flush where the car stands. This is the one situation that can only truly occur on a forecourt, as anywhere else the vehicle has been driven to get there.
Started for a moment, or just your ignition on. With the system primed, your lines and filter already hold petrol that came from your tank. Usually nothing more than clearing, cleaning and sorting the filter, and so still easy.
A couple of miles driven, and your pump has spent every one of them labouring on thinned fuel. Mileage is only half of that; how hard it was driven counts equally. Either way the work runs to the tank, the fuel lines, the filter and clean fuel through the entire system. Short trips, like the school run to Lavenham Community Primary School, are one thing. Getting as far as Colchester, under 25 miles away, makes a very different task — as does any miles on the M11, under 50 miles from Lavenham, with the engine working hard all the way.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That is your motor telling you its fuel no longer is behaving like diesel. Whether it's the verge on High Street, a lay-by or a side road, stop where you are and leave it. Long-term damage is very rare if a vehicle is stopped soon, and the drain and flush that still go first sort it out.
What Lavenham people get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A bigger tank of the same mix is all you get, since topping up takes out nothing. That guidance supposes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Protection matters more on newer diesels, not less, since their fuel passes through smaller components at higher pressure.
"It starts, it drives, and so no harm done" — the myth that catches more drivers than any other. Any petrol motor fed diesel usually won't run, so the motorist stops and the harm stops with them. Feed petrol to a diesel and it usually starts, ticks over and pulls away as if nothing happened — all while its pump wears. Running isn't the same as fine.
An old workaround for a distinct issue is 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, the tank still holds that petrol.
Myth: "Drain the tank yourself and you are sorted." Once the engine has been run, some of the petrol is no longer in the tank: it is in your filter and your lines, and it goes right back through the pump on the next start. On top of that, petrol emptied into a can by the road is truly dangerous.
Petrol in a diesel: how does it occur?
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle mostly will not go into a petrol motor, yet the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and just in that direction.
It occurs when habit and the car stop matching. Hire cars, courtesy cars, and vehicles that are new to you. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. Rushing for a train at Sudbury Suffolk and fuelling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: exactly when it takes place. Throw in rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
How to prevent petrol in a diesel at your next fill-up in Lavenham
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is just a hint.
- In a car you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of cars state the fuel there.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, in a household with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It seems daft and it does the trick.
- While you're thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Some diesels have a filler designed to block a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- Less petrol means a thinner mix, so stop as soon as you realise — though remembering that your next stage is unchanged. It is still not to crank it.
Already put petrol in a diesel in Lavenham?
Then the order of things is brief. Do not start the vehicle, and do not turn the ignition on. If you are still on the forecourt — the nearest petrol station or anywhere else — ask the staff to help you roll it clear of the petrol pump. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it has been run.
Say so if it was AdBlue instead of petrol: it's a different problem, with its own page for Lavenham, because AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel task in Lavenham costs more than another
The four situations above are four different tasks, so no single quote for this would be fair. What shifts the cost is mostly which of them you are in. The proportion matters next, meaning how much of your tank is petrol, followed by the position of the vehicle and whether getting to it is safe for a technician.
That is why our engineers ask three questions before costing instead of after: what was put in, how much, and if it has run. Those answers change a range into a straight figure.
About Lavenham and its setting
Lavenham is a village in Suffolk, situated on the banks of the River Brett at an elevation of around 67 metres. Lavenham lies approximately 57 miles from London and 16 miles from Colchester, with nearby villages including Washmere Green and Brent Eleigh. Lavenham has a mix of housing types, but is predominantly characterised by terraced homes. Lavenham is home to around 1224 residents, according to recent estimates.
Fuel drain cover in Lavenham and across Suffolk
Petrol in diesel call-outs in Lavenham — part of the CO postcode area — go to vans that likewise cover the spots round it, Washmere Green, Rooksey Green and Brent Eleigh included. The car doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump around Lavenham, still?
Then you are in the best position there can be. Keep the vehicle switched off, then ring.