Should You Worry? Petrol in a Diesel Car in Hotwells
Far less than you likely are, if it hasn't been started. "Have I wrecked it?" is the first thing anyone around Hotwells asks, and the truthful answer is generally no, since petrol resting in a diesel tank hurts nothing till it is drawn through the system — by ignition priming, by your starter, or by driving. Leave the engine off then phone Petrol in Diesel — that is how you keep it that way. The remainder of this page sets out what petrol actually does to a diesel, how to tell 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 tasks. It protects to begin with, and only then does it burn. Your high-pressure pump and the injectors are built to very fine tolerances, and the diesel passing through them is what stops those surfaces from grinding against each other.
Of those two tasks, petrol handles the first badly and the second not at all. It's runnier than diesel and strips away the protection your fuel system hinges on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That is where the knocking comes from.
Taken together, they make clear what shape the issue has. Contact doesn't do the harm — circulation does. Where that petrol is only inside that tank, it's a problem of fuel, nothing more. Once your pump has been working on that petrol, a mechanical fault has started: anything shed by a pump that's wearing down travels onward to the injectors with the fuel.
Petrol in a diesel in Hotwells: how bad is it? Four situations
Filled up, not once started. The best case there is. Only your tank has petrol in it, and so the job is clearing that tank and rinsing the fuel system where the car stands. This scenario can only really take place at a forecourt: anywhere else, the vehicle got there by being driven.
Started for a second, or just the ignition on. Your system has been bled, so petrol has left your tank and got to your filter and the lines. Still generally easy: drain, flush, and your filter dealt with.
Those few miles on the road were the pump working on fuel thinned by petrol throughout. Mileage is only half of it; how hard it was driven matters just as much. Either way the work includes the tank, your lines, the filter and clean fuel through the entire system. Driving the children to Hotwells Primary School is one kind of trip. A run as far as Bristol, under a mile away, is a very different task. So is any mileage on the M32, under 3 miles from Hotwells, where the engine has been working hard throughout.
Driven until it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. What you are hearing is the engine reporting fuel that no longer acts like diesel. Stop wherever you are — the verge on Hopechapel Hill, a lay-by, a side street — and leave it where it is. The drain and flush still go first, and they sort it out: when a car is stopped early, lasting damage is very unusual.
Petrol in a diesel myths Hotwells motorists hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — the tank just holds more of the same mixture. The idea behind that guidance — that diesel fuel systems accept petrol by percentage — is wrong.
"Modern diesels can handle a little petrol" — a myth, and closer to the opposite. A current diesel runs its fuel through smaller parts at higher pressure, which makes the protection matter more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no harm done." Diesel in a petrol motor normally leaves a motor that won't run: the motorist stops, and so does the damage. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while the pump grinds. Running isn't 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 distinct issue. What petrol has weakened remains diluted, and that petrol remains inside that tank anyway.
The next start sends petrol back round the pump out of the fuel lines and your filter, where some of that ends up once your engine has been run. That's why a DIY tank drain does not sort it — a myth. Draining petrol into a can by the kerbside is also really dangerous.
Why petrol in a diesel happens at all
A careless moment is seldom the cause, and no one means to do it. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol car. That is how the forecourt makes it simple.
Habit and the car getting out of step is when it takes place. A new car, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps laid out differently. A train to catch, and a hurried fill on the way to Clifton Down. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Renault Clio for the first time. Add a back seat full of children, a phone call or rain, and the hand wins.
How to prevent petrol in a diesel at your next fill-up in Hotwells
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what counts.
- The first fill in a strange vehicle is the time to check your filler flap — on it, or on the cap, many motors state which fuel they take.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, for a household with one of each.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new motor, say "diesel" aloud. Daft, yes, yet it works.
- Mistakes like this are simple to make while your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to reject a petrol nozzle, and aftermarket devices are available for the rest. Count it as a backstop, then keep checking the petrol pump.
- The moment you notice, stop: less petrol in that tank means a weaker mix. What to do next does not change, though — still don't crank it.
Put petrol in a diesel in Hotwells already?
Short and simple, then, is the order of things. Do not turn your ignition on, and don't fire it up. If you're still on the forecourt — Esso or anywhere else — ask the staff to help you push the car clear of the petrol pump. What went in, about how much, and if it has run: tell us those when you ring 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Hotwells has a page all for it.
What makes one Hotwells petrol in a diesel task cost more than the next
The four situations above are four different jobs, so no single price for this would be fair. Which of them you are in is mostly what shifts the cost. Beyond that it's the ratio — how much petrol was put in against how much your tank holds — and after that where your car is and whether a technician can reach it safely.
What was put in, how much, and whether it's run — three queries our engineers ask before costing, not after, for exactly that reason. The answers turn a range into a straight figure.
About Hotwells, briefly
Hotwells is a riverside suburban area in Bristol, situated near the city centre and overlooking the River Avon. Hotwells has a relatively low elevation of 22 metres and is close to nearby places such as Clifton Wood and Leigh Woods. Hotwells is predominantly composed of flat housing and is located approximately 0.9 miles from Bristol city centre. Hotwells is also near Victoria Park, a popular local green space.
Fuel drain cover around Hotwells and across Bristol
Hotwells rests in the BS postcode area, and our teams that answer petrol in diesel call-outs there work the spots around it as well — Clifton Wood, Leigh Woods and Victoria Park among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations we work, and the vehicle does not need to come to us.
At the petrol pump in Hotwells, right now?
Nothing beats it: that is where you are. Leave the vehicle switched off, and ring.