How Worried Should You Be? Petrol in a Diesel Car in Bromley
Provided it hasn't been started, worry less than you probably are. Till your ignition primes the pump, your starter turns, or your vehicle is driven, petrol in a diesel tank just waits there and does nothing. Which makes the truthful reply to the first Bromley question — "have I wrecked it?" — usually no. Petrol in Diesel is who to ring, with the engine kept off, and so it remains that way. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
Petrol in a diesel: what does it do to your engine?
Two jobs fall to diesel on its route round a motor. It burns, and before it combusts it lubricates. Your high-pressure pump and the fuel injectors are made to very fine clearances, and the diesel passing through them is what keeps those surfaces from wearing against each other.
Of those two tasks, petrol handles the first badly and the second not at all. The clattering comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection the system rests on, and any pump running on such a mix is wearing itself.
The shape of the problem is clear when you put those together. Not contact but movement is what does the harm. A tank with petrol in it is a fuel issue. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Bromley, petrol in a diesel: four situations, from mild to serious
Filled but not once started — the best it gets. At a forecourt, and genuinely only there, the petrol is still confined to the tank — because everywhere else the vehicle was driven to get to it. The task is draining and cleaning on the spot.
Ignition on, or started for a moment. Petrol has come out of that tank and got to the filter and your lines, since the fuel system has been primed. Drain, flush, deal with the filter: still usually easy.
Some miles driven, and your pump has spent each of them working on thinned fuel. Tank, lines, filter, then fresh fuel run through the entire circuit: that's the work, and the way the car was driven matters as much as the mileage. Short trips, such as the school run to St Agnes RC Primary School, are one matter. Very different once more: a run to London, under 5 miles away, or any distance on the M11, under 5 miles from Bromley, where your engine never stopped running hard.
Driven on till it protested — rattling, smoke, a ragged idle, a soft throttle. That's your motor telling you its fuel has stopped behaving like diesel. Whether it's the verge on Rounton Road, a lay-by or a side street, stop where you are then leave it. A vehicle stopped quickly very rarely has lasting damage, because the drain and the flush, which still go first, deal with it.
What Bromley motorists get told about petrol in a diesel — and the stories in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you're left with a fuller tank, still the same mixture. The assumption behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and nearer the opposite. At higher pressure, through finer components: that is how a current diesel moves its fuel, so the protection matters more, not less.
The myth that catches drivers off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel usually stops, since it will not run, and the harm stops with them. Feed petrol to a diesel and it normally fires up, ticks over and drives away as if nothing has happened — all while its pump is wearing. A running engine doesn't mean fine.
An outdated workaround for a separate issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol diluted is put back by it — and later, the tank still contains the petrol.
Myth: "Drain the tank yourself and you are sorted." After the motor has been run, some of that petrol is no longer in the tank: it's in the fuel filter and your lines, and it goes right back through your pump on your next start. On top of that, petrol emptied into a can by the road is genuinely dangerous.
Why petrol in a diesel happens so easily
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol motor at all. The forecourt makes it easy, and the error runs one way.
The moment habit stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a motor that is new. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps arranged differently. A rushed fill en route to West Ham with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that's when. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to prevent petrol in a diesel at your next fill-up around Bromley
- The label is what matters, so check the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- The first fill in a new motor is the time to check your filler flap — inside it, or on the cap, many motors state the fuel to use.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, in a home with one of each.
- Say it before you lift it. On your 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 does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away and keep your mind on the pump.
- Some diesels have a filler designed 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 reading the pump.
- Noticing it mid-fill? Stop there and then. A thinner blend results from less petrol inside the tank, but your next step stays the same: don't crank it.
Bromley: already put petrol in a diesel?
Then the order of things is short. Do not switch your ignition on, and don't start it. Ask the attendants to help you roll it away from the petrol pump if you're still on the forecourt, whether that's Texaco or anywhere else. What was put in, roughly how much, and if it has run: tell us that when you call 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a separate fault, with its own page for Bromley, since AdBlue brings corrosion and deposits instead of lost lubrication.
Why one petrol in a diesel task around Bromley costs more than another
Four different jobs sit behind the four scenarios above — which is why there is no fair single price. What moves your cost is chiefly which of them you are in. Two things come after that: the petrol that went in as a share of what your tank takes, then the place the vehicle is in and whether a technician can reach it safely.
Three queries come first, before any quote, instead of after — what went in, how much, has it run — and that is the reason. A range becomes a straight figure once those answers are in.
About Bromley and where it is
Bromley is a suburban area in Greater London, situated near the River Lea and close to the city of London. Bromley sits at a low elevation of around 17 metres, with its riverside location influencing the local environment. Bromley is characterized by a high proportion of flat dwellings, which reflect the area's urban setting. Bromley is also near to other local areas, including Bow Common and Mile End.
Fuel drain cover across Greater London, Bromley included
Petrol in diesel call-outs around Bromley — part of the E postcode area — go to teams that also cover the locations around it, Bow Common, Festubert Place and Mile End among them. Our engineers drain wherever the car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Still at the pump in Bromley?
Then you're in the best place there is. Keep it off. Ring.