Weston Park: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — as long as no one has started the car. "Have I wrecked it?" is the first question anyone in Weston Park asks, and the honest answer is usually no, since petrol left in a diesel tank hurts nothing until it's dragged through the fuel system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to ring, with your motor left off, so it remains that way. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and the way to make sure you never repeat it.
The engine and petrol in a diesel: what goes on
Diesel does two jobs on its way through an engine. Before it ignites, it protects — then it combusts. Built to extremely fine gaps, the injectors and your pump rely on the diesel flowing through them to keep their surfaces from wearing against one another.
Petrol does the first job badly and the second not at all. A pump running on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the protection your fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where the knocking comes.
Put these together and the shape of the trouble is clear. It is movement that does the damage, not contact. A tank with petrol in it is a fuel problem. Once your pump has been working on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing is carried downstream to the fuel injectors with your fuel.
How serious is petrol in a diesel? Four scenarios we see in Weston Park
Filled up, not once started. The best case there is. Only that tank has petrol in it, and so the task is draining your tank and purging the system where the vehicle sits. This situation can only truly happen on a forecourt: anywhere else, the vehicle got there by being driven.
A brief spell of running, or merely your ignition on. With the fuel system primed, your lines and filter now contain petrol that came from the tank. Usually nothing more than emptying, purging and seeing to the filter, and so still easy.
Those few miles on the road were the pump working on fuel diluted by petrol the whole way. The work is that tank, the lines, your filter and fresh fuel through the entire system, and how hard the vehicle was driven counts as much as how far. On the school run to St Mary's Catholic Primary School, the miles is small. Very different once more: a run to Bath, under 3 miles away, or any mileage on the M4, under 10 miles from Weston Park, where the motor never stopped running hard.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is your engine signalling fuel that no longer runs like diesel. Stop on the spot — on the verge on Weston Park, at the kerb, down a side road — and do not move it. The fuel drain and flush-through still go first, and they deal with it: when a car is pulled over quickly, permanent damage is very unusual.
Stories Weston Park drivers hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A fuller tank of the same mixture is all it gives, because topping up removes nothing. A diesel fuel system doesn't tolerate petrol by percentage in the way that guidance assumes.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." At higher pressure, through finer components: that is how a newer diesel moves its fuel, and so the lubrication matters more, not less.
One myth that catches motorists out: if it starts and drives, it must be unharmed. A petrol engine fed diesel normally won't run, so the driver stops and the damage stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, whilst your pump wears. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. It does not put back what petrol has weakened, and the petrol is still in that tank later on.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in your filter and lines, ready to go straight back through your pump on your next start. Besides, petrol cleared into a can by the road is genuinely risky.
Petrol in a diesel: how does it take place?
Nobody does it on purpose, and it is rarely carelessness. One way only, since of the nozzles: the smaller petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally won't fit a petrol motor. That's how the forecourt makes it easy.
Habit and your car getting out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the drive of the same household. A forecourt you know, but with its pumps laid out differently. Rushing for a train outside Oldfield Park and fuelling up en route. The first fill-up in a diesel Renault Megane after years of driving petrol is precisely the moment it happens. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Avoiding petrol in a diesel next time you fill up in Weston Park
- The label is what matters, so check the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of motors state the fuel type there.
- Label the key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It seems daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, so tuck your phone away and keep your mind on the pump.
- Add-on devices are available for motors without one, and some diesels are built with a filler that will not take a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- Less petrol means a thinner mix, and so stop as soon as you notice — while remembering that your next step is unchanged. It is still not to crank it.
Petrol already in a diesel in Weston Park? Start here
Then, there's just a short order of things. Do not fire it up, and do not switch your ignition on. The staff on the forecourt — whether at Sainsbury's itself or wherever you filled up — will normally help roll it clear of the pump if you ask. Call 0333 366 0103 next, with three facts — your fuel, the approximate amount, and whether it has run.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Weston Park, since AdBlue brings corrosion and deposits rather than lost protection.
What makes one Weston Park petrol in a diesel task cost more than the next
Four different jobs sit behind the four scenarios above — which is why there is no honest single price. Chiefly, the cost shifts with which one you are in. The ratio matters next, meaning how much of the tank is petrol, and then the position of the car and whether reaching it is safe for our van.
That's why we ask three queries before quoting instead of after: what got in, how much, and if it's run. With the replies, there is a straight figure rather than a range.
About Weston Park, briefly
Weston Park is a suburban area in Somerset, situated on the outskirts of Bath and adjacent to the lakeside. Weston Park sits at an elevation of 57 metres, with its semi-detached housing stock reflecting the residential character of the neighbourhood. Weston Park is close to other nearby places such as Combe Park, Primrose Hill, and Lower Weston, and is located approximately 1.2 miles from the city centre of Bath.
Weston Park and Somerset: where our fuel drain cover reaches
The teams answering petrol in diesel call-outs around Weston Park, in the BA postcode area, also work the places near it, Combe Park, Primrose Hill and Lower Weston among them. The car doesn't need to come to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the pump around Weston Park, still?
Nothing beats it: that's where you are. Turned off it stays; then ring.