Petrol in a Diesel Car in Showfield: How Worried Should You Be?
Not started? Then less anxious than you likely feel. Everyone in Showfield starts with "have I ruined it?", and the honest answer is usually no: petrol resting inside that tank of a diesel stays harmless till priming, cranking or driving pulls it into the system. Petrol in Diesel is who to call, with the engine left off, and so it stays that way. The rest of this page covers 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.
Inside the engine: what petrol in a diesel does
On its way through a motor, diesel has two tasks. It protects to begin with, and after that does it burn. The high-pressure fuel pump and the fuel injectors are designed to very fine gaps, and the diesel passing through them is what keeps those surfaces from wearing against each other.
Poorly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump running on the mixture wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you get the rattling.
Taken together, they show the shape the trouble has. Contact does not do the damage — movement does. Where the petrol is only inside that tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds travels on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical problem starts.
How bad is petrol in a diesel? Four scenarios our technicians see around Showfield
Fuelled but never started — as good as it gets. Being on a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With that petrol kept in your tank alone, it's emptied and rinsed right where it stands, and nothing more is needed.
The ignition switched on, or a short start. Once primed, your system has drawn petrol out of your tank as far as the filter and your lines. Normally little more than draining, cleaning and sorting the filter, so still simple.
A couple of miles driven, and the pump has spent every one of them running on diluted fuel. Mileage is only half of that; how hard it was driven matters equally. Either way this work runs to the tank, your lines, your filter and fresh fuel through the entire system. On the school run to St Anne's Catholic Primary School, the miles is small. Any mileage on the M606, under 10 miles from Showfield, means your engine has worked hard throughout, and a run to Bradford, under 10 miles away, is a very different task as well.
Driven till it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. The fuel isn't acting like diesel any more, and the engine is saying so. Pull up on the spot — on the verge on East Avenue, at the kerb, down a side road — and do not move it again. The drain and flush still go first, and they sort it out: if a vehicle is stopped early, lasting damage is very unusual.
Myths Showfield people hear about petrol in a diesel
Myth: 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 takes out nothing. The idea behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A modern diesel sends its fuel through finer parts at higher pressure, which makes the protection matter more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Feed diesel to a petrol engine and it normally will not run, and so the driver stops — and the harm stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, whilst your pump wears. Fine and running are not the same at all.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a distinct issue. That petrol is still in that tank afterwards, and what it has diluted isn't put back.
If the engine has run, part of the petrol is in the filter and the fuel lines, not your tank — and your next start sends it straight back through the pump. So the myth "drain the tank yourself and you're sorted" doesn't stand up. It is also really hazardous to drain petrol into a can by the kerbside.
How does petrol in a diesel take place?
On purpose? Never. Through carelessness? Rarely, if ever. One way only, since of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it simple.
When habit and the vehicle stop matching, it takes place. A new vehicle, a hire car or a courtesy car. Two cars on one driveway, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Racing for a train at Keighley and filling up en route. Years of petrol cars behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Next time you fill up in Showfield: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, but not on each forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of motors print the fuel type there.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of meaning to remember, for a house with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds silly and it does the trick.
- Put the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Add-on devices exist for cars without one, and some diesels come with a filler that will not accept a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- Noticing it halfway? Stop there and then. A thinner blend follows from less petrol in your tank, but the next stage remains the same: do not start it.
Put petrol in a diesel in Showfield already?
Then, there's only a short order of things. Do not switch your ignition on, and don't crank it. If you are still on the forecourt — Shell or anywhere else — ask the attendants to help you roll the car clear of the pump. Then phone 0333 366 0103 and tell us what went in, about how much, and if it's run.
Say so if it was AdBlue rather than petrol: it's a separate problem, with its own page for Showfield, since AdBlue brings corrosion and deposits instead of lost lubrication.
Showfield petrol in a diesel jobs: why one costs more than another
An honest single price doesn't exist here: four scenarios, four separate tasks. The scenario itself does most of the work of moving your cost. Beyond that it is the ratio — how much petrol was put in against how much the tank holds — and then where the car is and whether a technician can get to it safely.
That's why we ask three queries before pricing rather than after: what got in, how much, and whether it has run. With the replies, you get a straight figure instead of a range.
About Showfield, briefly
Showfield is a suburban area in West Yorkshire, situated approximately 8.5 miles from Bradford and 179.7 miles from London. Showfield sits at an elevation of around 110 metres, with its terraced housing stock reflecting the local architectural style. Showfield is located near other residential areas such as Lawkholme, Beechcliffe, and Highfield, and is home to a population of around 7893 people.
Showfield and West Yorkshire: where our fuel drain cover runs
Petrol in diesel jobs in Showfield — part of the BD postcode area — go to teams that also cover the locations around it, Lawkholme, Beechcliffe and Highfield included. No need to bring the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
At the petrol pump in Showfield, still?
No position is better: that's where you now are. Keep it off. Call.