Should You Worry? Petrol in a Diesel Car in Lawn
Less than you probably are, if it has not been started. Petrol sitting in a diesel tank does nothing to your engine until something draws it through the system — your ignition priming your pump, the starter, or driving on its own. So the fair answer to the first question anyone around Lawn asks, "have I wrecked it?", is usually no. Leave your motor off and ring Petrol in Diesel — that keeps it that way. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and the way to make sure you don't repeat it.
Inside the engine: what petrol in a diesel does
On its way through an engine, diesel has two jobs. Before it burns, it protects — then it ignites. Extremely fine clearances are built into the injectors and the high-pressure pump, and only your diesel running through stops those surfaces grinding together.
The second job petrol doesn't do at all, and the first it does badly. The knocking comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system depends on, and any pump working on that blend is wearing itself.
Put these together and the shape of the issue is clear. Contact doesn't do the damage — circulation does. A tank with petrol in it is a fuel issue. The beginning of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors downstream.
How bad is petrol in a diesel? Four scenarios we see in Lawn
Fuelled, and not started: nothing beats it. Being on a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With the petrol kept inside the tank alone, it is cleared and cleaned right where it stands, and nothing more is needed.
Ignition on, or started for a second. Once primed, the system has drawn petrol out of your tank as far as the fuel filter and your lines. Normally little more than emptying, purging and seeing to the filter, and so still simple.
Your pump has spent a few miles on thinned fuel — that's what driving the vehicle does. The work is the tank, your lines, the fuel filter and fresh fuel through the whole circuit, and how hard your car was driven matters as much as how far. Driving the children to Lawn Primary and Nursery School is one sort of trip. Any mileage on the M4, under a mile from Lawn, means the motor has worked hard throughout, and a run to Oxford, under 50 miles away, is a very different job too.
Driven until it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. That is your engine telling you its fuel no longer is acting like diesel. Stop wherever you are — the verge on Marlborough Road, a lay-by, a side street — and leave it there. The fuel drain and flush still go first, and they sort it out: if a vehicle is pulled over soon, lasting damage is very unusual.
Petrol in a diesel stories Lawn people hear
False: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mix is all it gives, because topping up removes nothing. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Not so: a modern diesel copes with a bit of petrol. Rather, the reverse. A modern diesel runs its fuel through smaller components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that catches motorists. Feed diesel to a petrol engine and it normally won't run, and so the motorist stops — and the harm stops with them. While the pump grinds, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Being able to run isn't proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct problem. None of what petrol diluted is put back by it — and afterwards, that tank still contains that petrol.
Myth: "Drain that tank yourself and you're sorted." After the engine has been run, some of that petrol is no longer inside the tank: it is in your filter and the fuel lines, and it goes right back through your pump at your next start. And, a can of petrol filled at the kerbside is truly hazardous.
Why petrol in a diesel happens so easily
It is seldom carelessness, and no one does it on purpose. A diesel nozzle mostly will not go into a petrol car, but the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error simple, and just in one direction.
It takes place when habit and the vehicle stop matching. A motor that's new to you — a hire car, on loan as a courtesy car, or just bought. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Racing for a train at Swindon and filling up en route. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Throw in a back seat full of children, a phone call or rain, and the hand wins.
Lawn drivers: how to avoid petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Go by the label on the petrol pump, not the colour.
- Many vehicles state the fuel type inside the filler flap or on the cap, so check there on your first fill in a car you do not know.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key when a home has one of each. So label it.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Daft, perhaps, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and aftermarket devices exist for the remainder. Treat it as a safety net, and keep reading the petrol pump.
- Less petrol makes a weaker mixture, and so stop the moment you notice — though remembering that the next step is unchanged. It's still not to crank it.
Put petrol in a diesel in Lawn already?
Short and simple, then, is the order of things. Leave it unstarted, with your ignition off as well. The staff at the forecourt — whether at Shell itself or wherever you filled up — will normally help push it away from the petrol pump if you ask. Call 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and whether it's run.
Say so if it was AdBlue rather than petrol: it is a separate fault, with its own page for Lawn, since AdBlue brings corrosion and deposits instead of lost lubrication.
One petrol in a diesel task around Lawn costs more than another. Why?
The four situations above are four separate tasks, so no single quote for this would be fair. Which of them you are in is mostly what moves your cost. Beyond that it's the ratio — how much petrol went in against how much your tank takes — and then where your car is and whether our van can reach it safely.
Before any quote, not after, we ask three questions: your fuel that was put in, its amount, and if it has run. That's why. Those answers change a range into a straight figure.
About Lawn, briefly
Lawn is a suburban area in Wiltshire, situated inland at an elevation of around 128 metres, and is located near the cities of Swindon and Oxford. Lawn forms part of the larger urban area surrounding Swindon, with nearby places including Coate, Old Town, and Liden. Lawn has a population of approximately 3280 residents, predominantly living in detached housing.
Across Wiltshire and around Lawn: fuel drain cover
Petrol in diesel jobs around Lawn — part of the SN postcode area — go to vans that likewise cover the locations around it, Coate, Old Town and Liden included. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
In Lawn and still at the pump?
Then you are in the best place there is. Ring, and leave it turned off.