Should You Worry? Petrol in a Diesel Car in Rounds Green
Probably less than you are now — as long as nobody has started the vehicle. Until your ignition primes the pump, the starter cranks, or the car is driven, petrol in a diesel tank just rests there and does no harm. Which means the truthful reply to the first Rounds Green question — "have I ruined it?" — usually no. Keep it like that: leave the motor off and ring Petrol in Diesel. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
What petrol in a diesel does to your engine
Two jobs fall to diesel on its route round a motor. Lubricating comes before burning; it does both. What keeps the surfaces inside the high-pressure pump and the fuel injectors from wearing down against each other is the diesel flowing through them — they are designed to very fine tolerances.
Poorly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump running on the blend to wear itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the clattering.
Taken together, they show what shape the issue has. Contact does not do the harm — movement does. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds travels on, carried by your fuel, into the injectors downstream, which is why a pump that has been working on that petrol is where a mechanical issue starts.
Petrol in a diesel in Rounds Green: how bad is it? Four cases
The best case there can be: filled up, never started. At a forecourt, and genuinely only there, that petrol is still confined to the tank — since everywhere else the vehicle was driven to get to it. The task is emptying and cleaning on the spot.
The ignition turned on, or a short start. With the system primed, your lines and filter already contain petrol that came from the tank. Normally nothing more than draining, purging and sorting your filter, and so still easy.
Those few miles driven were your pump working on fuel diluted by petrol the whole way. Tank, lines, filter, then fresh fuel put through the entire system: that is this work, and the way the car was driven matters as much as the miles. On the school run to Rounds Green Primary School, the miles is small. A run as far as Birmingham, under 10 miles away, is a very different job. So is any miles on the M5, under a mile from Rounds Green, where the motor has been working hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. What you are hearing is your engine reporting fuel that no longer acts like diesel. Pull up on the spot — on the verge on Brades Road, at the kerb, down a side road — and do not move it. Long-term damage is very uncommon when a car is stopped soon, and the fuel drain and flush-through that still go first deal with it.
Stories Rounds Green motorists hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mix is all you get, since topping up removes nothing. That advice assumes a diesel fuel system tolerates petrol by percentage. It does not.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through smaller parts: that is how a current diesel moves its fuel, and so the lubrication counts more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor usually leaves a motor that will not run: the motorist stops, and so does the harm. Feed petrol to a diesel and it usually fires up, idles and pulls away as if nothing has happened — all while its pump wears. Being able to run isn't the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. None of what petrol thinned is put back by it — and later, the tank still holds that petrol.
The next start draws petrol back round your pump out of the fuel lines and the filter, where some of that ends up once the engine has run. That's why a DIY tank drain doesn't sort it — a myth. Also, a can of petrol filled by the roadside is genuinely dangerous.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
Routine and the car falling out of step is when it occurs. Hire cars, courtesy cars, and motors that are new to you. Two motors on one driveway, one petrol, one diesel. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill en route to Sandwell & Dudley. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it happens. With rain, a call coming in, or a car full of children to deal with, the hand just does what it always has.
Rounds Green drivers: how to prevent petrol in a diesel next time
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what matters.
- The first fill in a new motor is the time to check the filler flap — inside it, or on the cap, many vehicles state which fuel they take.
- Mark your key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending 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 pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away then keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and add-on devices are available for the rest. Count it as a backstop, and keep reading the petrol pump.
- Stop as soon as you notice. Less petrol in your tank means a weaker mixture. It doesn't change what to do next, which is still not to crank it.
Rounds Green: already put petrol in a diesel?
The order of things is short, then. Do not turn your ignition on, and don't crank it. Ask the attendants to help you roll it clear of the pump if you're still on the forecourt, whether that is Esso or somewhere else. What got in, about how much, and whether it's run: tell us that when you call 0333 366 0103.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate problem — Rounds Green has a page just for it.
One petrol in a diesel job in Rounds Green costs more than another. Why?
There's no fair single price for this, since the four scenarios above are four different jobs. Mostly, the cost moves with which one you are in. Where the vehicle is counts too, and whether our van can safely reach it, after the ratio of petrol to what the tank holds.
Ahead of any quote, not after, come three queries: the fuel that was put in, the volume, and whether it has run. That's why. Those answers turn a range into a straight figure.
About Rounds Green, for a moment
Rounds Green is a suburban area located near the River Tame in the West Midlands, with a mix of semi-detached housing and local amenities. Rounds Green sits at an elevation of 144 metres, approximately 5.5 miles southwest of Birmingham city centre. Rounds Green is close to nearby places such as Oldbury, Brades Village, and the Grace Mary Estate, and is home to around 3877 residents. Rounds Green forms part of the larger urban area surrounding Birmingham, with easy access to the city and its facilities.
Fuel drain cover around Rounds Green and across West Midlands
Oldbury, Brades Village and Grace Mary Estate are among the spots around Rounds Green that the same teams work, answering petrol in diesel calls across Rounds Green's B postcode area. The vehicle 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 driveway.
At the petrol pump around Rounds Green, still?
The best place there is, then — that's where you are. Keep it off. Call.