Methley: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you likely are. Until the ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank simply waits there and does no harm. Which means the honest reply to that first Methley question — "have I ruined it?" — normally no. To keep it that way, call Petrol in Diesel and leave your motor switched off. Below, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Inside the motor: what petrol in a diesel does
Diesel does two jobs on its way through an engine. It combusts, and before it combusts it protects. Built to very fine tolerances, the injectors and the pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Poorly at the first, not at all at the second: that's petrol. The knocking comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection your system depends on, and any pump running on such a blend is wearing itself.
Together, those make the shape of the trouble clear. Not contact but movement is what does the harm. Any tank with petrol in it is a fuel fault. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
Petrol in a diesel in Methley: how bad is it? Four situations
Fuelled up, not once started. The best case there is. At a forecourt, and really only there, the petrol is still confined to that tank — since anywhere else your car was driven to get to it. The job is emptying and flushing on the spot.
A moment's running, or merely your ignition on. Petrol has left the tank and got to the fuel filter and the fuel lines, because the system has been primed. Normally little more than emptying, flushing and seeing to the filter, so still easy.
Those few miles on the road were your pump running on fuel diluted by petrol throughout. The work is that tank, the lines, the fuel filter and fresh fuel through the entire system, and how hard the car was driven matters as much as how far. The school run to Methley Primary School is one matter. Very different again: a trip to Wakefield, under 10 miles away, or any miles on the M62, under 3 miles from Methley, where the motor never stopped labouring hard.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. What you are hearing is the motor signalling fuel that no longer acts like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on Little Church Lane. The fuel drain and flush still go first, and they take care of it: if a car is pulled over early, long-term damage is very unusual.
Petrol in a diesel myths Methley drivers hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A fuller tank of the same mix is all you get, because topping up takes out nothing. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. Finer components and higher pressure are how a modern diesel runs its fuel, and that makes the protection matter more, not less.
"It starts, it drives, so no harm done" — the myth that trips up most drivers than any other. Any petrol motor fed diesel usually won't run, and so the motorist stops and the damage stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, whilst the pump wears. Running doesn't mean fine.
Not so: a two-stroke additive makes it safe to drive home. It is an old workaround, supposed for another fault. None of what petrol thinned is put back by it — and afterwards, the tank still contains the petrol.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the filter and lines, ready to go straight back through the pump at your next start. Emptying petrol into a can by the kerbside is also genuinely dangerous.
Petrol in a diesel: how does it occur?
Carelessness is seldom the cause, and no one means to do it. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol vehicle at all. So the error runs one way.
It occurs when routine and the vehicle stop matching. Hire cars, courtesy cars, and cars that are new to you. Two vehicles on one drive, one petrol, one diesel. Your usual forecourt, its pumps now in a different order. A rushed fill en route to Woodlesford with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you at the forecourt for its first tank — that is when. Add a back seat full of kids, a phone call or rain, and habit wins.
How to avoid petrol in a diesel at your next fill-up in Methley
- Read 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 matters.
- Plenty of motors state the fuel inside your filler flap or on the cap, so check there on your first fill in a motor you don't know.
- Good intentions count for less than a sticker or a fob in a bright colour on the diesel's key if a household has one of each. So mark it.
- Say it before you lift it. On your 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 does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so put the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices are available for cars without one. They are a backstop, not a reason to stop checking the petrol pump.
- Less petrol means a thinner mixture, and so stop as soon as you realise — while remembering that the next stage is unchanged. It is still not to start the vehicle.
Petrol already in a diesel in Methley? Start here
Then the order of things is short. Starting it is out, and so is switching on your ignition. The attendants on the forecourt — whether at CNG Fuels itself or wherever you filled up — will normally help roll it clear of the pump if you ask. Next, 0333 366 0103. We'll ask what got in, about how much, and if it has been run.
Say so if it was AdBlue rather than petrol: it is a separate fault, with its own page for Methley, because AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel task in Methley costs more than another. Why?
There is no fair single quote for this, because the four scenarios above are four different tasks. Mostly, the cost shifts with which one you are in. Two things follow that: the petrol that went in as a share of what that tank takes, then the place the car is in and whether a technician can reach it safely.
That's why our technicians ask three questions before pricing instead of after: what got in, how much, and whether it's run. With those replies, there is a straight figure instead of a range.
About Methley
Methley is a small village in West Yorkshire, situated on the riverside at an elevation of 22 metres. Methley lies close to the city of Wakefield, approximately 5 miles away, and is near other local places such as Wood Row and Mickletown. Methley has a population of around 560 people and predominantly features detached housing. Methley is located about 163 miles north of London.
Methley and West Yorkshire: where our fuel drain cover reaches
Methley rests in the LS postcode area, and our teams that answer petrol in diesel call-outs there work the locations around it as well — Wood Row, Mickletown and Methley Junction among them. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all locations where we work.
In Methley and still at the petrol pump?
The best spot there is, then — that is where you are. Keep it off. Call.