How Worried Should You Be? Petrol in a Diesel Car in Lees
Provided it has not been started, worry far less than you likely are. Petrol sitting in a diesel tank does nothing to your motor until something pulls it through the system — your ignition priming the pump, your starter, or driving on its own. So the truthful answer to the first question everyone in Lees asks, "have I ruined it?", is generally no. Petrol in Diesel is who to call, with the engine kept off, and so it stays that way. What petrol really does to a diesel, how to gauge how far it's gone, and how to stop it from happening a second time: that's the rest of this page.
Petrol in a diesel: what does it do to the engine?
Passing through an engine, diesel is doing two things at once. It combusts, and before it burns it lubricates. Built to very fine clearances, your injectors and the pump rely on your diesel flowing through them to stop their surfaces wearing against one another.
Petrol handles the first job badly and the second not at all. A pump working on a petrol blend is wearing itself out, since petrol is thinner than diesel and strips out the protection the fuel system relies on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where the knocking comes.
Seen together, they show what shape the trouble takes. Not contact but circulation is what causes the harm. Petrol in the tank is a fuel problem. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the injectors further on.
How bad is petrol in a diesel? Four scenarios we see in Lees
Fuelled, and never started: no case is better. Only the tank has petrol in it, so the task is draining that tank and cleaning the system where your car sits. This scenario can only really occur on a forecourt: anywhere else, your car got there by being driven.
Ignition on, or started for a second. Once primed, the fuel system has drawn petrol from the tank up to the fuel filter and the lines. Usually little more than draining, purging and seeing to your filter, and so still easy.
A couple of miles driven, and the pump has spent every one of them working on diluted fuel. Tank, lines, filter, then fresh fuel put through the whole system: that is the work, and the way the car was driven matters as much as the miles. The school run to Lees Primary School is one matter. Driving as far as Bradford, under 10 miles away, makes a very different task — as does any distance on the M606, under 10 miles from Lees, with the motor labouring hard the whole time.
Driven until it complained. Rattling, a ragged idle, smoke, a throttle that has gone soft. What you are hearing is the motor reporting fuel that no longer runs like diesel. Pull up wherever you are — the verge on Laburnum Grove, a lay-by, a side street — and leave the vehicle there. The drain and flush-through still come first, and they deal with it: if a vehicle is stopped soon, lasting damage is very unusual.
Myths Lees motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. Percentage isn't how a diesel fuel system copes with petrol, whatever that advice presumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel runs its fuel through finer parts at higher pressure, which makes the lubrication matter more, not less.
"It starts, it drives, and so no harm done" — the myth that catches more drivers than any other. A petrol engine fed diesel generally will not run, and so the motorist stops and the damage stops with them. Whilst your pump wears, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Fine and running aren't the same thing.
An old fix for a different issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." The petrol is still in your tank after that, and what it has thinned isn't put back.
Myth: "Drain the tank yourself and you are sorted." After the engine has run, some of the petrol is no longer inside your tank: it's in the filter and the fuel lines, and it goes right back through your pump on your next start. Besides, petrol drained into a can by the road is truly risky.
Why petrol in a diesel happens at all
It's seldom carelessness, and no one does it on purpose. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol car at all. So the mistake runs one way.
When routine and your car stop matching, it happens. Hire cars, courtesy cars, and vehicles that are new to you. Two motors on one drive, one petrol, one diesel. A well-known forecourt with the pumps in a different order. A train to catch, and a hurried fill on the way to Keighley. Exactly the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Throw in a back seat full of children, a phone call or rain, and the hand takes over.
Next time you fill up in Lees: preventing petrol in a diesel
- Green for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- Check the filler flap. Plenty of cars state the fuel inside the flap or on the cap. Look at it on your first fill in a motor you do not know.
- Label your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems silly. It does the trick.
- While you are thinking about something else, this is an easy mistake to make — so tuck the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices are available for motors without one. They are a backstop, not a reason to stop checking the petrol pump.
- Stop the moment you realise. Less petrol in the tank means a thinner blend. It doesn't change what to do next, which is still not to crank it.
Put petrol in a diesel around Lees already?
Then the order of things is short. Don't crank it, and do not turn your ignition on. Still on the forecourt, at Shell or anywhere else? Ask the staff to help you roll the vehicle clear of the pump. What went in, roughly how much, and if it's run: tell us those when you call 0333 366 0103.
Say so if it was AdBlue instead of petrol: it is a separate issue, with its own page for Lees, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task in Lees costs more than another
A fair single price doesn't exist here: four scenarios, four separate tasks. What moves your cost is chiefly which of them you're in. Beyond that it is the ratio — how much petrol got in against how much the tank holds — and then where the vehicle is and whether a van can reach it safely.
Three questions come first, before any quote, rather than after — what went in, how much, has it run — and this is the reason. Those answers are what change a range into one firm number.
About Lees itself
Lees is a suburban area in West Yorkshire, situated near several lakes and reservoirs at an elevation of 212 metres. Lees lies approximately 8 miles from Bradford and is characterised by its predominantly terraced housing stock. Lees is one of several small communities in the area, including nearby Cross Roads, Lane End, and Barcroft. Lees has a population of around 3299 residents.
Lees and West Yorkshire: where our fuel drain cover runs
The teams answering petrol in diesel call-outs in Lees, in the BD postcode area, equally work the spots near it, Cross Roads, Lane End and Barcroft among them. You need not bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Still at the petrol pump in Lees?
The best place there is, then — that's where you are. Keep it off. Phone.