Petrol in a Diesel Car in Chinbrook: How Worried Should You Be?
If it has not been started, you can worry less than you likely are. Petrol resting in a diesel tank does nothing to your motor till something draws it through the system — your ignition priming the pump, the starter, or the drive itself. So the fair answer to the first question anyone around Chinbrook asks, "have I ruined it?", is generally no. To leave it like that, phone Petrol in Diesel and leave the motor switched off. 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 does not happen to you a second time.
What petrol in a diesel does to the motor
On its way through an engine, diesel does two jobs. It lubricates first, and only then does it burn. Made to very fine gaps, your injectors and your pump rely on the diesel moving through them to stop their surfaces wearing against one another.
Badly at the first, not at all at the second: that's petrol. A pump working on a petrol mixture 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 wants from its fuel — and that is where any clattering starts.
Together, those make the shape of the problem clear. It's movement that causes the damage, not contact. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds goes on, borne by the fuel, into the fuel injectors further along, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Four situations we see around Chinbrook: how serious is petrol in a diesel?
Fuelled up, not once started. The best case there is. The petrol is in the tank and only your tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only truly take place on a forecourt, because anywhere else the car has been driven to get there.
A brief spell of running, or just the ignition on. The system has been bled, and so petrol has left your tank and reached your filter and the lines. Still usually simple: drain, flush, and your filter sorted.
Driven a few miles. Now the pump has spent those miles labouring on thinned fuel. Tank, lines, filter, then clean fuel put through the whole circuit: that's the work, and the way the car was driven matters as much as the miles. On the school run to Marvels Lane Primary School, the miles is small. A run as far as London, under 10 miles away, is a very different task. So is any miles on the M20, under 10 miles from Chinbrook, where the motor has been running hard throughout.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone uneven. The motor is telling you your fuel is no longer behaving like diesel. Leave it wherever it has stopped: a lay-by, a quiet street, the verge on Chinbrook Road. A car pulled over early very rarely has lasting damage, because the fuel drain and the flush, which still go first, deal with it.
Chinbrook motorists and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Topping up takes out nothing; it gives you a fuller tank of the same mix. A diesel fuel system does not tolerate petrol by percentage in the way that guidance supposes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise parts: that is how a newer diesel handles its fuel, and so the lubrication counts more, not less.
The myth that catches motorists out: if it starts and drives, it must be unharmed. Diesel in a petrol motor generally means a motor that won't run: the motorist stops, and so does the damage. While the pump wears, a diesel fed petrol normally starts, idles and drives away as though nothing has happened. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. It doesn't put back what petrol has weakened, and that petrol is still inside that tank after that.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in the filter and lines, waiting to go straight back through your pump on the next start. On top of that, petrol cleared into a can by the road is genuinely dangerous.
Petrol in a diesel: how does it occur?
Nobody does it on purpose, and it is seldom carelessness. The petrol nozzle is the narrower of the two and slides 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 slip runs one way.
When routine and your car stop matching, it happens. Hire cars, courtesy cars, and cars that are new to you. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a well-known forecourt. A rushed fill en route to Grove Park with a train to catch. The first fill-up in a diesel Volkswagen Passat after years of driving petrol is exactly the moment it occurs. With rain, a call arriving, or a car full of children to deal with, your hand just does what it has always done.
Avoiding petrol in a diesel next time you fill up around Chinbrook
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the pump's label; the colour is just a hint.
- Inspect the filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any motor you don't know.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, in a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It sounds daft and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, and so put your phone away then keep your mind on the petrol pump.
- Add-on devices are available for cars without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- As soon as you realise, stop: less petrol inside your tank makes a thinner mixture. What to do next does not change, though — still don't fire it up.
Put petrol in a diesel around Chinbrook already?
Then the order of things is short. Never crank it, and do not turn the ignition on. Yet at the forecourt, at Esso or anywhere else? Ask the staff to help you roll the car clear of the petrol pump. What got in, about how much, and whether it's run: tell us those when you ring 0333 366 0103.
Corrosion and deposits form the trouble with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and read its own Chinbrook page.
Chinbrook petrol in a diesel tasks: why one costs more than another
The four situations above are four separate tasks, so no single price for this would be honest. What moves the cost is mostly which of them you're in. The proportion matters next, meaning how much of the tank is petrol, followed by the location of the car and whether getting to it is safe for our van.
That's why we ask three queries before quoting rather than after: what got in, how much, and if it has run. A range turns into a straight figure once the answers are in.
About Chinbrook and where it is
Chinbrook is a suburban area in southeast London, situated on the banks of the River Ravensbourne at an elevation of around 41 metres. Chinbrook lies approximately 8.6 miles from central London and is close to neighbouring areas such as Grove Park and Mottingham. Chinbrook is characterised by its predominantly terraced housing stock, reflecting the typical residential architecture of the region. Chinbrook forms part of the larger London urban landscape, with nearby Plaistow also being a significant local centre.
Chinbrook and Greater London: where our fuel drain cover runs
Our vans answering petrol in diesel calls around Chinbrook, in the SE postcode area, equally work the locations near it, Grove Park, Mottingham and Plaistow included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers work, and the car doesn't need to come to us.
In Chinbrook and still at the pump?
The best spot there is, then — that's where you are. Leave the car switched off, then ring.