Petrol in a Diesel Car in Kentsboro: How Worried Should You Be?
Probably less than you already are — as long as nobody has started the car. "Have I ruined it?" is the first question anyone in Kentsboro asks, and the honest answer is generally no, because petrol resting in a diesel tank harms nothing till it's dragged through the system — by ignition priming, by your starter, or by being driven. Leave the engine off then ring Petrol in Diesel — that keeps it like that. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has got, and ways to make sure you never do it again.
The motor and petrol in a diesel: what happens
Diesel does two tasks on its way through an engine. It protects first, and after that does it burn. Designed to very fine tolerances, the fuel injectors and your pump depend on the diesel flowing through them to stop their surfaces wearing against one another.
Of these two jobs, petrol manages the first badly and the second not at all. A pump running on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any knocking comes.
Put those together and the shape of the issue is clear. It's movement that does the damage, not contact. Petrol in a tank is a fuel issue. Whatever a worn pump sheds goes on, carried by your fuel, into the fuel injectors further along, which is why a pump that has worked on the petrol is where a mechanical problem begins.
How serious is petrol in a diesel? Four scenarios our technicians see in Kentsboro
Fuelled up, not once started. The best case there is. At a forecourt, and genuinely only there, the petrol is still confined to that tank — since everywhere else your car was driven to get to it. The task is emptying and flushing on the spot.
Your ignition switched on, or a brief start. With the system primed, the lines and filter already hold petrol that has come from your tank. Still usually straightforward: drain, flush, and the fuel filter dealt with.
A couple of miles driven, and the pump has spent every one of them labouring on thinned fuel. Tank, lines, filter, then clean fuel put through the entire system: that is the work, and the way your car was driven counts as much as the distance. On the school run to Wallop Primary School, the distance is small. Any distance on the M3, under 15 miles from Kentsboro, means your engine working hard throughout, and a run to Salisbury, under 15 miles away, makes a very different task too.
It complained, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. The fuel isn't acting like diesel any more, and the motor is saying so. Stop where you are — on the verge on Upper Mead, at the kerb, down a side road — and do not move it again. A car pulled over soon very seldom has lasting damage, because the drain and the flush-through, which still go first, deal with it.
Petrol in a diesel myths Kentsboro drivers hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. Percentage is not how a diesel fuel system tolerates petrol, however much that advice assumes.
Myth: a modern diesel copes with a bit of petrol. If anything, the opposite. At higher pressure, through smaller components: that's how a newer diesel handles its fuel, so the protection matters for more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that catches drivers. The motorist of a petrol motor fed diesel normally stops, since it will not run, and the damage stops there. Feed petrol to a diesel and it normally starts, ticks over and drives away like nothing has happened — all while its pump is wearing. Running does not mean fine.
An old fix for a separate problem lies behind this one. Myth: "Add some two-stroke oil and drive the car home." It doesn't put back what petrol has diluted, and the petrol is still in that tank afterwards.
The next start sends petrol back round your pump from the fuel lines and the fuel filter, where some of that sits once your engine has run. That is why a DIY tank drain doesn't sort it — a myth. Besides, petrol drained into a can by the road is genuinely risky.
How petrol ends up: petrol in a diesel
A careless moment is rarely the cause, and nobody 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 will not go into a petrol vehicle at all. So the slip runs one way.
Habit and the car getting out of step is how it occurs. A new car, a hire car or a courtesy car. Two motors on one driveway, one petrol, one diesel. A familiar forecourt with the pumps in a different order. Filling up in a rush en route to Grateley, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: exactly when it happens. With rain, a call coming in, or children to deal with, the hand simply does what it always has.
Next time you fill up in Kentsboro: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the petrol pump's label; the colour is only a hint.
- Plenty of vehicles state the fuel inside your filler flap or on the cap, and so check there on your first fill in any vehicle you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a house has one of each. So label it.
- It seems daft and it works: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Whilst you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and add-on devices are available for the remainder. Treat it as a safety net, then keep checking the petrol pump.
- Less petrol means a thinner blend, so stop the moment you notice — while remembering that the next stage is unchanged. It's still not to crank it.
Already put petrol in a diesel in Kentsboro?
The order of things is brief, then. Starting it is out, and so is turning on your ignition. The staff at the forecourt — whether at White Horse Service Station itself or wherever you filled up — will usually help roll it away from the pump if you ask. Ring 0333 366 0103 next, with three facts — your fuel, the rough quantity, and if it's run.
Say so if it was AdBlue instead of petrol: it's a different fault, with its own page for Kentsboro, because AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel job in Kentsboro costs more than another. Why?
There is no fair single price for this, since the four scenarios above are four separate tasks. What moves your cost is mostly which of them you're in. Where the car is counts too, and whether a van can safely reach it, after the share of petrol to what that tank takes.
What got in, how much, and if it's run — three queries our technicians ask before pricing, not after, for precisely that reason. Those answers change a range into a straight figure.
About Kentsboro
Kentsboro is a small village in Hampshire, situated inland at an elevation of 98 metres, with semi-detached housing being the predominant type. Kentsboro lies near the villages of Middle Wallop and Over Wallop, and is approximately 11.8 miles from Salisbury. Kentsboro is also within commuting distance of London, being around 66.5 miles away. Kentsboro has a population of around 933 residents.
Kentsboro and Hampshire: where our fuel drain cover reaches
Our teams answering petrol in diesel call-outs in Kentsboro, in the SO postcode area, equally work the locations near it, Middle Wallop, Clatford Oakcuts and Over Wallop among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots our engineers drain, and the car doesn't need to come to us.
At the petrol pump in Kentsboro, still?
No position is better: that's where you now are. Leave the car turned off, then ring.