Should You Worry? Petrol in a Diesel Car in East Chinnock
Probably less than you are now — as long as no one has started the vehicle. Till the ignition primes your pump, your starter cranks, or your car is driven, petrol in a diesel tank simply rests there and does no harm. Which makes the honest reply to the first East Chinnock question — "have I ruined it?" — normally no. To leave the car like that, ring Petrol in Diesel and leave your engine switched off. The rest of this page explains what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Inside the motor: what petrol in a diesel does
Two jobs fall to diesel on its journey through a motor. It protects to begin with, and after that does it burn. What stops the surfaces inside the high-pressure pump and the fuel injectors from grinding against one another is the diesel passing through them — they're made to extremely fine gaps.
Badly at the first, not at all at the second: that is petrol. It's runnier than diesel and removes the protection your 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 reverse of what a diesel needs from its fuel. That's where the knocking comes from.
The shape of the issue is plain when you put those together. Contact doesn't do the harm — circulation does. Petrol in the tank is a fuel issue. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to your injectors downstream.
Four situations our engineers see around East Chinnock: how bad is petrol in a diesel?
Filled up, and never started: no case is better. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol held in that tank alone, it's drained and flushed right where it stands, and nothing more is needed.
A moment's running, or merely the ignition on. Your system has been primed, and so petrol has left your tank and got to the filter and the fuel lines. Normally nothing more than draining, purging and seeing to the filter, so still simple.
A few miles driven, and your pump has spent each of them labouring on diluted fuel. The work is your tank, the fuel lines, the filter and fresh fuel through the entire system, and how hard the car was driven matters as much as how far. On the school run to West Coker CofE VC Primary School, the distance is small. A run as far as Wells, under 25 miles away, is a very different job. So is any miles on the M5, under 25 miles from East Chinnock, where the engine has been labouring hard the whole time.
Driven on till it protested — rattling, smoke, a lumpy idle, a dead throttle. The motor is telling you the fuel is no longer behaving like diesel. Whether it's the verge on Forge Lane, a lay-by or a side street, stop where you are then leave it. Lasting damage is very uncommon if a car is pulled over quickly, and the fuel drain and flush that still go first sort it out.
East Chinnock motorists and that petrol in a diesel stories they hear
Myth: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a fuller tank of the same mix. The assumption behind that advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel sends its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that catches motorists. The driver of a petrol engine fed diesel usually stops, because it will not run, and the damage stops there. Whilst your pump grinds, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Being able to run is not the same as being fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old fix for a different fault. What petrol has diluted remains thinned, and that petrol remains inside your tank anyway.
Myth: "Drain that tank yourself and you are sorted." Once the motor has been run, some of the petrol is no longer in that tank: it is in the fuel filter and the lines, and it goes right back through the pump on your next start. Besides, petrol emptied into a can by the road is genuinely dangerous.
Petrol in a diesel: how does it happen?
Nobody does it on purpose, and it's seldom carelessness. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips 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 occurs when habit and your car stop matching. A new vehicle, a hire car or a courtesy car. Households running one of each, petrol and diesel. The pumps in a different order on a familiar forecourt. Racing for a train outside Crewkerne and fuelling up en route. The first fill-up in a diesel Volkswagen Tiguan after years of driving petrol is exactly the moment it occurs. With rain, a call coming in, or a car full of children to deal with, the hand simply does what it always has.
How to prevent petrol in a diesel at your next fill-up around East Chinnock
- The label is what matters, so check the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Inspect the filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key when a house has one of each. So label it.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It sounds daft and it works.
- Mistakes like this are simple to make whilst your mind is on something else, and so your phone goes away.
- Some diesels have a filler designed to reject a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Stop as soon as you realise. Less petrol in your tank means 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 around East Chinnock?
Then the order of things is brief. Don't turn your ignition on, and do not crank it. Still on the forecourt, at Murco or anywhere else? Ask the attendants to help you roll the vehicle away from the pump. Then ring 0333 366 0103 and tell us what was put in, roughly how much, and if it has run.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits instead of lost protection — and it has its own page for East Chinnock.
What makes one East Chinnock petrol in a diesel task cost more than the next
There is no honest single price for this, since the four scenarios above are four different jobs. Mostly, the cost shifts with which one you're in. Where the vehicle is matters too, and whether a technician can safely reach it, after the proportion of petrol to what that tank takes.
Three questions come first, before any quote, instead of after — what was put in, how much, has it run — and that is the reason. With those replies, there is a straight figure rather than a range.
About East Chinnock itself
East Chinnock is a small village in Somerset, situated near the River Parrett and surrounded by rolling hills. East Chinnock has a low elevation of around 44 metres and is located near several other villages, including Hardington Mandeville and Middle Chinnock. East Chinnock is characterized by its predominantly detached housing stock and is a relatively small community with a population of approximately 503 people.
Fuel drain cover around East Chinnock and across Somerset
East Chinnock rests in the BA postcode area, and the vans that answer petrol in diesel jobs there work the locations near it as well — Hardington Mandeville, Middle Chinnock and West Coker among them. Our technicians drain wherever the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump around East Chinnock, right now?
Then you're in the best spot there can be. Switched off it stays; then call.