Should You Worry? Petrol in a Diesel Car in Market Deeping
Less than you likely are, if it hasn't been started. Petrol resting in a diesel tank does nothing to your engine till something pulls it through the system — the ignition priming the pump, the starter, or driving itself. So the honest answer to the first query anyone around Market Deeping asks, "have I ruined it?", is normally no. To keep the vehicle like that, call Petrol in Diesel and leave your motor alone. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has spread, and ways to make sure you never repeat it.
Inside your engine: what petrol in a diesel really does
Passing through an engine, diesel is doing two things at once. It combusts, and before it burns it protects. The high-pressure fuel pump and the fuel injectors are made to very fine gaps, and the diesel passing through them is what keeps those surfaces from grinding against each other.
Of those two tasks, petrol manages the first poorly and the second never. A pump running on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the protection your fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the clattering comes.
The shape of the problem is clear when you put those together. It is movement that does the damage, not contact. Where that petrol is only inside the tank, it is a fault of fuel, nothing more. The beginning of a mechanical one is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors beyond it.
Four situations our engineers see in Market Deeping: how serious is petrol in a diesel?
Fuelled but not once started — the best it gets. On a forecourt, and really only there, the petrol is still confined to your tank — because everywhere else your car was driven to reach it. The job is draining and purging on the spot.
Started for a moment, or only your ignition on. Once primed, your system has pulled petrol from the tank as far as the filter and the fuel lines. That's usually still a simple task — a drain, a flush, and the filter seen to.
Those few miles on the road were your pump working on fuel diluted by petrol throughout. Distance is only half of that; how hard it was driven counts equally. Either way the work includes that tank, the lines, your filter and fresh fuel through the whole system. On the school run to William Hildyard Church of England Primary and Nursery School, the miles is small. A run as far as Peterborough, under 10 miles away, is a very different job. So is any mileage on the Great North Road, under 10 miles from Market Deeping, where the engine has been working hard the whole time.
Driven on until it complained — knocking, smoke, a ragged idle, a soft throttle. That's your engine telling you its fuel has stopped acting like diesel. Leave it wherever it stops: a lay-by, a quiet street, the verge on Stamford Road. A vehicle stopped soon very seldom has lasting damage, because the drain and the flush-through, which still come first, deal with it.
Stories Market Deeping people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Topping up removes nothing; it gives you a bigger tank of the same mixture. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice assumes.
"Modern diesels can handle a little petrol" — a myth, and nearer the reverse. A current diesel runs its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
The myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally will not run, and so the driver stops — and the harm stops with them. While your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Being able to run isn't the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. It doesn't put back what petrol has weakened, and the petrol is still in the tank later on.
The next start draws petrol back round your pump out of the lines and your filter, where some of it sits after the motor has run. That's why a DIY tank drain doesn't sort it — a myth. Emptying petrol into a can by the kerbside is also truly dangerous.
How does petrol in a diesel occur?
Nobody does it on purpose, and it's seldom carelessness. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That's how the forecourt makes it easy.
It takes place when habit and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. A train to catch, and a hurried fill en route to Stamford. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Preventing petrol in a diesel next time you fill up around Market Deeping
- A green handle for unleaded and black for diesel is normal in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before the first fill: many cars print the fuel there.
- Mark the key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Before the nozzle leaves the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Silly, perhaps, but it works.
- Put the phone away. This is an easy mistake to make while 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 vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Less petrol makes a weaker mixture, so stop as soon as you realise — while remembering that the next stage is unchanged. It is still not to start it.
Petrol already in a diesel around Market Deeping? Start here
In that case, there is just a short order of things. Starting it is out, and so is switching on your ignition. Ask the staff to help you push it clear of the petrol pump if you're still at the forecourt, whether that is The Co-operative or somewhere else. Then ring 0333 366 0103 and tell us what got in, roughly how much, and if it has run.
Corrosion and deposits form the problem with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and see its own Market Deeping page.
Market Deeping petrol in a diesel jobs: why one costs more than another
The four situations above are four different tasks, so no single price for this would be fair. The situation itself does most of the work of moving your cost. Beyond that it is the ratio — how much petrol went in against how much that tank takes — and after that where your car is and whether a technician can get to it safely.
That's why our technicians ask three questions before costing instead of after: what was put in, how much, and if it has run. A range becomes a straight figure when those answers are in.
About Market Deeping, briefly
Market Deeping is a town situated on the banks of the River Welland in Lincolnshire, with a population of around 11024 people. Market Deeping has a mix of housing types, but detached homes are particularly prevalent, and the town's elevation is approximately 11 metres above sea level. Market Deeping is located near several smaller communities, including The Rectory, Deeping Gate, and Castle End, and is close to the city of Peterborough. Market Deeping benefits from its riverside setting, which has influenced the town's development over time.
Fuel drain cover in Market Deeping and across Lincolnshire
Market Deeping waits in the PE postcode area, and the teams that answer petrol in diesel calls there work the locations around it as well — The Rectory, Deeping Gate and Castle End among them. We 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.
Market Deeping: still at the pump?
The best spot there is, then — that's where you are. Keep the car turned off, and ring.