How Worried Should You Be? Petrol in a Diesel Car in Wembury
If it has not been started, worry far less than you probably are. Until the ignition primes the pump, your starter turns, or your car is driven, petrol in a diesel tank simply waits there and does no harm. Which makes the honest reply to that first Wembury question — "have I ruined it?" — usually no. Keep it like that: leave your motor off then call Petrol in Diesel. Further down, you will find what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
Passing through a motor, diesel is doing two things at the same time. It ignites, and before it burns it lubricates. What stops the surfaces inside the high-pressure fuel pump and the injectors from wearing down against each other is the diesel passing through them — they're built to extremely fine tolerances.
Petrol handles the first task badly and the second not at all. It's runnier than diesel and strips away the protection the system rests on, so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the trouble is clear when you put those together. Not contact but movement is what does the harm. All a tank with petrol in it amounts to is a fuel issue. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors further on.
Wembury, petrol in a diesel: four cases, from mild to significant
Fuelled, and not started: no case is better. That petrol is in your tank and just the tank, and the task is a drain and a flush where the car stands. This is the one situation that can only really occur on a forecourt, as anywhere else the car has been driven to get there.
Ignition on, or started for a second. With the system primed, the lines and filter already contain petrol that came from that tank. Normally little more than emptying, cleaning and seeing to your filter, and so still straightforward.
A couple of miles driven, and the pump has spent each of them working on diluted fuel. Mileage is only half of it; how hard it was driven counts equally. Either way the work runs to your tank, the fuel lines, your filter and fresh fuel through the entire system. The school run to Wembury Primary School is one thing. Getting as far as Plymouth, under 5 miles away, makes a very different task — as does any distance on the M5, under 50 miles from Wembury, with the engine labouring hard all the way.
Driven until it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and your motor is saying so. Pull up on the spot — on the verge on Ford Road, at the kerb, down a side road — and do not move it. The drain and flush still go first, and they deal with it: when a vehicle is stopped soon, permanent damage is very unusual.
Petrol in a diesel stories Wembury motorists hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system copes with petrol, however much that advice supposes.
"Modern diesels can handle a little petrol" — a myth, and closer to the reverse. At higher pressure, through smaller parts: that is how a newer diesel moves its fuel, so the lubrication matters more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more people than any other. Any petrol engine fed diesel normally will not run, so the motorist stops and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, whilst the pump wears. Running isn't the same as fine.
An outdated fix for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive it home." It doesn't put back what petrol has weakened, and the petrol is still in that tank later on.
Myth: "Drain your tank yourself and you are sorted." After the motor has run, some of the petrol is no longer inside that tank: it's in the filter and the fuel lines, and it goes right back through your pump on the next start. Draining petrol into a can at the roadside is also genuinely risky.
Petrol in a diesel: how does it happen?
Carelessness is rarely the cause, and no one means to do it. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol vehicle at all. So the error runs one way.
It happens when routine and your car stop matching. A motor that is new to you — hired, on loan as a courtesy car, or brand new. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a familiar forecourt. A train to catch, and a rushed fill on the way to Plymouth. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: exactly when it occurs. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Avoiding petrol in a diesel next time you fill up in Wembury
- The label is what counts, and so read the pump rather than the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Many cars state the fuel inside the filler flap or on the cap, and so check it on your first fill in a car you do not know.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of meaning to remember, in a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It sounds daft and it does the trick.
- While you're thinking about something else, this is an easy mistake to make — so put the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices are available for motors without one. They are a safety net, not a reason to stop checking the pump.
- Stop the moment you realise. Less petrol inside your tank makes a weaker mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel in Wembury?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. Yet at the forecourt, at Asda or anywhere else? Ask the attendants to help you roll it away from the petrol pump. Ring 0333 366 0103 next, with three answers — your fuel, the rough amount, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate problem — Wembury has a page all for it.
One petrol in a diesel job in Wembury costs more than another. Why?
The four scenarios above are four separate tasks, so no single quote for this would be honest. Chiefly, your cost shifts with which one you are in. The proportion matters next, meaning how much of your tank is petrol, followed by the position of your car and whether reaching it is safe for a van.
Three questions come first, before any quote, rather than after — what was put in, how much, has it run — and that is the reason. Those answers are what turn a range into one firm number.
About Wembury itself
Wembury is a coastal village in south Devon, situated near the city of Plymouth and overlooking the Plymouth Sound. Wembury sits on the southern edge of Dartmoor National Park, with its highest point at around 74 metres, and is close to nearby places such as Knighton and Hollacombe. Wembury is characterised by its predominantly detached housing stock and a population of around 1272 residents.
Fuel drain cover around Wembury and across Devon
The teams answering petrol in diesel jobs in Wembury, in the PL postcode area, also work the spots around it, Knighton, Hollacombe and Hollacombe Hill included. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
Still at the petrol pump in Wembury?
Then you are in the best place there can be. Keep it turned off, and ring.