How Worried Should You Be? Petrol in a Diesel Car in Knights Enham
Probably less than you are now — provided nobody has started it. Petrol resting in a diesel tank does nothing to the motor until something pulls it through your fuel system — your ignition priming your pump, the starter, or driving itself. So the honest answer to the first question everyone around Knights Enham asks, "have I wrecked it?", is usually no. Keep it that way: leave the engine off and phone Petrol in Diesel. What petrol really does to a diesel, how to judge how far it has travelled, and how to stop it from happening a second time: that's the rest of this page.
Inside the motor: what petrol in a diesel does
On its way through an engine, diesel does two jobs. It protects first, and after that does it burn. Very fine gaps go into the fuel injectors and your high-pressure pump, and only the diesel running through stops those surfaces grinding together.
Badly at the first, not at all at the second: that is petrol. A pump working on a petrol mixture is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where any knocking comes.
Put these together and the shape of the problem is clear. It's movement that causes the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. The start 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 the injectors downstream.
Petrol in a diesel in Knights Enham: how serious is it? Four situations
Fuelled, and not started: nothing beats it. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held inside the tank alone, it's emptied and purged right where it stands, and nothing more is needed.
Ignition on, or started for a moment. Petrol has left the tank and reached your filter and your lines, because the system has been primed. Drain, flush, deal with the filter: still normally simple.
Those few miles on the road were the pump labouring on fuel weakened by petrol throughout. The work is that tank, your lines, the fuel filter and fresh fuel through the whole circuit, and how hard the car was driven counts as much as how far. Driving the kids to Roman Way Primary School is one sort of trip. Very different again: a trip to Winchester, under 15 miles away, or any distance on the M3, under 15 miles from Knights Enham, where the engine kept working hard.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The engine is telling you the fuel is no longer acting like diesel. Whether it is the verge on Saxon Way, a lay-by or a side street, stop where you are and leave it. Permanent damage is very unusual when a car is stopped quickly, and the drain and flush-through that still come first deal with it.
Knights Enham motorists and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed when you top up — your tank just carries more of the same blend. That guidance presumes a diesel fuel system handles petrol by percentage. It does not.
"Newer diesels can handle a little petrol" — a myth, and nearer the reverse. A current diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that fools motorists. The driver of a petrol motor fed diesel usually stops, because it will not run, and the harm stops there. While your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different problem. That petrol is still inside your tank after that, and whatever it has diluted is not put back.
The next start sends petrol back round your pump from your lines and the filter, where some of it ends up after the engine has been run. That is why a DIY tank drain does not leave you sorted — a myth. And, a can of petrol filled by the kerbside is truly risky.
How petrol ends up: petrol in a diesel
It is seldom carelessness, and nobody does it on purpose. The petrol nozzle is the smaller of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
It happens when habit and the vehicle stop matching. Courtesy car, hire car, or a motor that is new. A household with one petrol and one diesel on the drive. The pumps in a different order on a familiar forecourt. Racing for a train at Andover and fuelling up en route. Years of petrol cars behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that's when. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up around Knights Enham: preventing petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Read the petrol pump's label; the colour is just a clue.
- The first fill in an unfamiliar motor is the time to check your filler flap — on it, or on the cap, plenty of vehicles state which fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key when a house has one of each. So label it.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Put your phone away. This is an easy mistake to make while you are thinking about something else.
- Some diesels come with a filler built to block a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- As soon as you notice, stop: less petrol inside the tank makes a thinner blend. What to do next doesn't change, though — still don't start it.
Put petrol in a diesel around Knights Enham already?
Then, there is just a short order of things. Leave it unstarted, with the ignition switched off too. Still on the forecourt, at Tesco or anywhere else? Ask the attendants to help you push the vehicle clear of the pump. Then ring 0333 366 0103 and tell us what went in, roughly how much, and whether it has run.
Corrosion and deposits are the issue with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and see its own Knights Enham page.
One petrol in a diesel job around Knights Enham costs more than another. Why?
Four separate tasks sit behind the four situations above — which is why there's no fair single price. What moves the cost is chiefly which of them you are in. The share matters next, meaning how much of that tank is petrol, and then the location of the car and whether getting to it is safe for our van.
Three questions come first, before any quote, instead of after — what got in, how much, has it run — and that is the reason. Those answers are what change a range into one firm number.
About Knights Enham and where it is
Knights Enham is a small hamlet in Hampshire, situated inland at an elevation of 76 metres, and is located near the cities of Winchester and Andover. Knights Enham sits within a network of rural settlements, including nearby East Anton, Enham Alamein, and Charlton, and is characterized by its predominantly detached housing stock. Knights Enham is also relatively close to major urban centres, with London approximately 61.5 miles to the east and Winchester 13.8 miles to the south.
Fuel drain cover in Knights Enham and across Hampshire
East Anton, Enham Alamein and Charlton are among the spots near Knights Enham that the same vans work, answering petrol in diesel jobs across Knights Enham's SP postcode area. The car doesn't need to come to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Knights Enham and still at the pump?
Then you're in the best place there can be. Keep it off. Phone.