Should You Worry? Petrol in a Diesel Car in Pot Common
Provided it hasn't been started, you can worry far less than you likely are. Everyone around Pot Common begins with "have I wrecked it?", and the fair answer is normally no: petrol resting inside your tank of any diesel remains harmless till priming, cranking or driving draws it into the fuel system. Leave your motor off and call Petrol in Diesel — that is how you keep it like that. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and the way to make sure you never repeat it.
The motor and petrol in a diesel: what goes on
Passing through a motor, diesel is doing two jobs at the same time. Before it ignites, it lubricates — then it burns. Your high-pressure pump and the fuel injectors are built to very fine gaps, and your diesel passing through them is what keeps those surfaces from wearing against one another.
Badly at the first, not at all at the second: that's petrol. The rattling comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection the system hinges on, and any pump running on such a mixture is wearing itself.
The shape of the problem is plain once you put those together. It is circulation that causes the damage, not contact. Petrol in the tank is a fuel issue. After the pump has been running on that petrol, a mechanical issue has started: whatever is shed by a pump that is grinding travels onward to the injectors with the fuel.
Petrol in a diesel in Pot Common: how bad is it? Four situations
Filled up, and not started: nothing beats it. Only that tank has petrol in it, and so the job is clearing that tank and flushing the system where the car sits. This situation can only really occur at a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a moment. Once primed, your system has pulled petrol out of the tank as far as the filter and your lines. Usually little more than draining, purging and seeing to the filter, so still easy.
The pump now spent a couple of miles on thinned fuel — that's what driving the vehicle meant. Mileage is only half of that; how hard it was driven counts just as much. Either way the work includes the tank, your lines, the fuel filter and clean fuel through the entire system. Short trips, like the school run to St James CofE Aided Primary School, are one matter. Any distance on the M3, under 10 miles from Pot Common, means the engine working hard throughout, and a run to Chichester, under 25 miles away, makes a very different task as well.
Driven till it complained. Rattling, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is your motor signalling fuel that no longer runs like diesel. Stop wherever you are — the verge on Thursley Road, a lay-by, a side street — then leave the vehicle where it is. What goes first is still the fuel drain and flush-through, and that deals with it, with long-term damage very rare if a car is pulled over soon.
Myths Pot Common drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Topping up takes out nothing; it gives you a bigger tank of the same mix. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance presumes.
Myth: a current diesel copes with a bit of petrol. Rather, the opposite. Smaller components and higher pressure are the way a current diesel runs its fuel, and that makes the protection matter more, not less.
"It starts, it drives, so no harm done" — the myth that catches more drivers than any other. Diesel in a petrol motor generally leaves a motor that won't run: the driver stops, and so does the harm. While the pump grinds, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Being able to run is not proof of being fine.
Myth: a two-stroke additive makes it safe to drive home. It was an old fix, meant for another issue. That petrol is still in the tank afterwards, and whatever it has weakened isn't put back.
Myth: "Drain that tank yourself and you're sorted." After the engine has run, some of that petrol is no longer in the tank: it's in the filter and the lines, and it goes right back through the pump on the next start. And, a can of petrol drained by the kerbside is genuinely hazardous.
Petrol in a diesel: how does it occur?
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol motor. That is how the forecourt makes it simple.
It occurs when routine and the vehicle stop matching. Courtesy car, hire car, or a vehicle that's brand new. Households running one of each, petrol and diesel. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill en route to Milford (Surrey). A new-to-you diesel Volkswagen Tiguan, its first fuelling, and a driver accustomed to petrol: exactly when it occurs. Add rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Preventing petrol in a diesel next time you fill up in Pot Common
- The label is what counts, so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Inspect the filler flap. Many cars state the fuel type inside the flap or on the cap. Look at it on your first fill in a motor you don't know.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key if a home has one of each. So label it.
- Before the nozzle leaves the petrol pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Silly, perhaps, yet it works.
- While you're thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Add-on devices exist for vehicles without one, and some diesels come with a filler that won't take a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol inside your tank makes a thinner blend. What to do next doesn't change, though — still don't fire it up.
Petrol already in a diesel around Pot Common? Start here
Then the order of things is brief. Do not turn your ignition on, and don't crank it. Ask the staff to help you push it clear of the pump if you're still at the forecourt, whether that's Esso or somewhere else. Next, 0333 366 0103. We will ask what got in, roughly how much, and if it's been run.
Corrosion and deposits are the problem with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and see its own Pot Common page.
Why one petrol in a diesel task around Pot Common costs more than another
There is no fair single price for this, because the four scenarios above are four separate jobs. What shifts the cost is mostly which of them you're in. The ratio counts next, meaning how much of the tank is petrol, and then the location of the car and whether getting to it is safe for a technician.
What went in, how much, and if it has run — three questions our engineers ask before quoting, not after, for exactly that reason. Those answers are what change a range into one firm number.
About Pot Common itself
Pot Common is a suburban area in Surrey, situated on the riverside at an elevation of 53 metres, with detached housing being the predominant type of accommodation. Pot Common lies near the villages of Elstead and Tilford Common, and is also close to Charleshill. Pot Common is located 34.1 miles from London and 23.6 miles from Chichester, making it a relatively rural suburb in the South East region.
Fuel drain cover across Surrey, Pot Common included
The vans answering petrol in diesel call-outs in Pot Common, in the GU postcode area, also work the locations near it, Elstead, Charleshill and Tilford Common included. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our technicians work, and your car doesn't need to move to us.
At the petrol pump in Pot Common, still?
No position is better: that's where you now are. Keep the vehicle switched off, then ring.