Petrol in a Diesel Car in Coningsby: How Worried Should You Be?
If it hasn't been started, you can worry less than you probably are. "Have I ruined it?" is the first thing everyone around Coningsby asks, and the honest answer is usually no, since petrol left in a diesel tank harms nothing till it's dragged through your fuel system — by ignition priming, by your starter, or by being driven. To leave the vehicle that way, phone Petrol in Diesel and leave the engine alone. 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.
Inside the motor: what petrol in a diesel does
Two tasks fall to diesel on its route round a motor. Before it ignites, it lubricates — and then it combusts. Built to extremely fine clearances, the fuel injectors and your pump rely on your diesel flowing through them to stop their surfaces wearing against one another.
The second job petrol doesn't do at all, and the first it does badly. A pump running on a petrol blend is wearing itself out, because petrol is runnier than diesel and takes away the protection your fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the knocking starts.
Put these together and the shape of the issue is clear. Not contact but circulation is what does the harm. Any tank with petrol in it is a fuel issue. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors further along, which is why a pump that has been working on the petrol is where a mechanical issue begins.
Four situations our technicians see in Coningsby: how serious is petrol in a diesel?
Fuelled, and not started: no case is better. On a forecourt, and really only there, the petrol is still confined to the tank — since everywhere else the vehicle was driven to get to it. The task is emptying and rinsing on the spot.
A brief spell of running, or just your ignition on. Your system has been primed, so petrol has left that tank and reached the fuel filter and the fuel lines. Drain, flush, see to the filter: still normally simple.
Driven a couple of miles. Now the pump has spent those miles working on diluted fuel. How hard the car was driven counts as much as how far, and the work covers your tank, your lines, the fuel filter and clean fuel through the whole circuit. On the school run to Coningsby St Michael's Church of England Primary School, the distance is short. Getting as far as Lincoln, under 25 miles away, makes a very different job — as does any distance on the M180, under 50 miles from Coningsby, with the motor working hard the whole time.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. The motor is telling you the fuel is no longer acting like diesel. Pull up wherever you are — the verge on Park Lane, a lay-by, a side street — then leave it there. What goes first is still the drain and flush, and that takes care of it, with lasting damage very unusual if a vehicle is pulled over quickly.
What Coningsby people get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing comes out when you top up — that tank just holds more of the same mixture. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance supposes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. A current diesel runs its fuel through finer parts at higher pressure, which makes the lubrication count more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it usually won't run, so the motorist stops — and the damage stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, whilst the pump wears. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. It does not put back what petrol has diluted, and the petrol is still in the tank later.
Once the motor has run, part of that petrol sits in your filter and your lines, not your tank — and your next start pulls it straight back through the pump. So the myth "drain that tank yourself and you're sorted" does not stand up. Also, a can of petrol filled by the roadside is truly dangerous.
How petrol ends up: petrol in a diesel
It's seldom carelessness, and no one does it on purpose. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
Habit and the car falling out of step is how it happens. Courtesy car, hire car, or a motor that is brand new. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps arranged differently. Racing for a train at Metheringham and filling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: exactly when it occurs. Throw in rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up in Coningsby: avoiding petrol in a diesel
- The label is what counts, so read the petrol pump rather than the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- Plenty of vehicles state the fuel inside the filler flap or on the cap, and so check there on the first fill in a car you don't know.
- Label your key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" aloud. 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 built to reject a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the pump.
- Less petrol means a thinner blend, and so stop as soon as you notice — though remembering that the next stage is unchanged. It's still not to crank it.
Put petrol in a diesel in Coningsby already?
Then the order of things is brief. Never start the car, and don't switch your ignition on. If you are still at the forecourt — Gulf or anywhere else — ask the staff to help you push it clear of the pump. Then phone 0333 366 0103 and tell us what was put in, about how much, and if it's run.
If it was AdBlue rather than petrol, say so. That's a separate fault — corrosion and deposits and not lost protection — and it has its own page for Coningsby.
Why one petrol in a diesel job in Coningsby costs more than another
The four scenarios above are four separate jobs, so no single price for this would be honest. Which of them you're in is chiefly what shifts your cost. Two things follow that: the petrol that went in as a proportion of what the tank holds, then the place the car is in and whether a van can reach it safely.
That's why our technicians ask three queries before pricing rather than after: what was put in, how much, and if it's run. With the answers, there is a straight figure instead of a range.
About Coningsby and where it is
Coningsby is a village situated on the banks of the River Witham in Lincolnshire, with a low elevation of around 9 metres. Coningsby lies near the market town of Tattershall and is approximately 17.6 miles from the city of Lincoln. Coningsby has a mix of old and new housing, with detached homes being the predominant type, and is surrounded by nearby places such as Tattershall Thorpe and Moor Side.
Fuel drain cover across Lincolnshire, Coningsby included
Petrol in diesel jobs in Coningsby — part of the LN postcode area — go to teams that likewise cover the places around it, Tattershall Thorpe, Tattershall and Moor Side included. The car does not need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump around Coningsby?
Then you are in the best position there can be. Keep it turned off, and ring.