Petrol in a Diesel Car in Doe Green: How Worried Should You Be?
Less than you probably are, if it hasn't been started. Petrol resting in a diesel tank does nothing to your engine until something draws it through the system — the ignition priming your pump, your starter, or driving on its own. So the fair answer to the first question anyone in Doe Green asks, "have I wrecked it?", is normally no. To leave the car that way, ring Petrol in Diesel and leave the engine alone. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening again: that's the rest of this page.
Inside the engine: what petrol in a diesel really does
Diesel does two jobs on its way through a motor. Before it combusts, it protects — and then it burns. The high-pressure pump and the fuel injectors are built to very fine gaps, and the diesel passing through them is what stops those surfaces from grinding against one another.
Badly at the first, not at all at the second: that is petrol. The knocking comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection your system depends on, and any pump running on that mix is wearing itself.
Put those together and the shape of the trouble is plain. Contact doesn't do the damage — movement does. All a tank with petrol in it amounts to is a fuel problem. The beginning of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to the fuel injectors beyond it.
Doe Green, petrol in a diesel: four cases, from mild to serious
The best case there can be: filled up, never started. That petrol is inside the tank and only your tank, and the job is a drain and a flush where the car stands. This is the one scenario that can only really happen at a forecourt, since anywhere else your car has been driven to get there.
A brief spell of running, or just the ignition on. With your system primed, the fuel lines and filter already contain petrol that has come from that tank. Still normally easy: drain, flush, and the filter dealt with.
Driven a few miles. Now the pump has spent those miles working on thinned fuel. Tank, lines, filter, then clean fuel run through the entire system: that is the work, and the way your car was driven matters as much as the mileage. Short trips, like the school run to Penketh Primary School, are one thing. Getting as far as Liverpool, under 15 miles away, makes a very different job — as does any mileage on the M62, under 3 miles from Doe Green, with the motor working hard all the way.
Driven until it protested. Clattering, a lumpy idle, smoke, a throttle that has gone soft. That's the motor telling you its fuel no longer is behaving like diesel. Leave it wherever it stops: a lay-by, a quiet street, the verge on Beech Avenue. The drain and flush still come first, and they sort it out: when a car is pulled over early, long-term damage is very uncommon.
What Doe Green people get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A fuller tank of the same mix is all you get, because topping up takes out nothing. Percentage isn't how a diesel fuel system copes with petrol, whatever that advice assumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A newer diesel runs its fuel through more precise 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 catches people. Diesel in a petrol motor usually means a motor that won't run: the driver stops, and so does the harm. Feed petrol to a diesel and it usually fires up, ticks over and drives away as if nothing has happened — all while its pump is wearing. Fine and running aren't the same thing.
Myth: a two-stroke additive lets you to drive home. It is an old workaround, supposed for another issue. What petrol has thinned remains thinned, and that petrol stays in that tank anyway.
If your engine has been run, part of the petrol sits in your filter and your lines, not the tank — and your next start pulls it right back through your pump. So the myth "drain your tank yourself and you're sorted" does not stand up. And, a can of petrol drained at the roadside is genuinely hazardous.
Petrol in a diesel: how does it occur?
Carelessness is rarely the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol vehicle at all. So the mistake runs one way.
It occurs when routine and the vehicle stop matching. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. Fuelling up in a rush on the way to Sankey for Penketh, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it happens. Add rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
Doe Green drivers: how to prevent petrol in a diesel next time
- Check the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what matters.
- Inspect the filler flap. Plenty of vehicles state the fuel type inside the flap or on the cap. Look at it on the first fill in a vehicle you do not know.
- A coloured fob or a sticker on your diesel's key achieves more than any amount of intending to remember, for a home with one of each.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car gets its first tank. It sounds daft. It works.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for cars without one. They are a safety net, not a reason to stop reading the petrol pump.
- Stop as soon as you realise. Less petrol in your tank means a thinner blend. It doesn't change what to do next, which is still not to start the car.
Petrol already in a diesel in Doe Green? Start here
The order of things is brief, then. Don't crank it, and do not switch your ignition on. The attendants on the forecourt — whether at BP itself or wherever you filled up — will usually help push it away from the petrol pump if you ask. What got in, about how much, and whether it's run: tell us that when you call 0333 366 0103.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits rather than lost lubrication — and it has its own page for Doe Green.
Why one petrol in a diesel job in Doe Green costs more than another
There is no fair single price for this, because the four scenarios above are four different tasks. Chiefly, your cost shifts with which one you are in. After that it's the proportion — how much petrol went in against how much your tank takes — and after that where the vehicle is and whether a technician can reach it safely.
Three queries come first, before any quote, rather than after — what was put in, how much, has it run — and that is the reason. Given the answers, there is a straight figure instead of a range.
About Doe Green itself
Doe Green is a suburban area in Cheshire, situated near the coast and approximately 12.8 miles from Liverpool. Doe Green has a relatively low elevation of 16 metres and is surrounded by nearby places such as Penketh and Cuerdley Cross. Doe Green is characterised by its predominantly semi-detached housing stock, which is typical of many suburban areas in the North West of England.
Across Cheshire and in Doe Green: fuel drain cover
The teams answering petrol in diesel calls around Doe Green, in the WA postcode area, equally work the spots around it, Penketh, Cuerdley Cross and Lingley Green among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our technicians work, and the vehicle doesn't need to move to us.
Still at the petrol pump around Doe Green?
Then you're in the best place there can be. Turned off it remains; then call.