Should You Worry? Petrol in a Diesel Car in Lower Birchwood
Less than you probably are, provided it hasn't been started. Till your ignition primes your pump, your starter turns, or your car is driven, petrol in a diesel tank simply sits there and does nothing. Which makes the truthful reply to the first Lower Birchwood question — "have I ruined it?" — usually no. Petrol in Diesel is who to ring, with the motor kept off, so it stays that way. Below, this page sets out what petrol actually does inside a diesel, how far it may have gone, and how to stop it happening to you a second time.
Petrol in a diesel: what does it do to the motor?
Diesel does two jobs on its way through a motor. It protects first, and only then does it burn. What keeps the surfaces inside the high-pressure pump and the injectors from wearing down against one another is your diesel flowing through them — they are made to extremely fine gaps.
The second job petrol doesn't do at all, and the first it does poorly. The rattling 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 away the protection your system depends on, and any pump running on that mixture is wearing itself.
Together, those leave the shape of the issue clear. Not contact but circulation is what does the harm. A tank with petrol in it is a fuel problem. After the pump has been labouring on that petrol, a mechanical issue has started: whatever is shed by a pump that's wearing down travels onward to your injectors with the fuel.
Four scenarios our engineers see in Lower Birchwood: how bad is petrol in a diesel?
Fuelled, and not started: nothing beats it. At a forecourt, and truly only there, the petrol is still confined to the tank — since everywhere else your car was driven to get to it. The job is emptying and flushing on the spot.
Your ignition switched on, or a brief start. The fuel system has been bled, and so petrol has left the tank and reached the fuel filter and your lines. Usually nothing more than clearing, purging and sorting the fuel filter, so still straightforward.
Some miles driven, and the pump has spent each of them working on diluted fuel. The work is the tank, the lines, the filter and fresh fuel through the whole circuit, and how hard the vehicle was driven counts as much as how far. Driving the kids to Somercotes Infant and Nursery School is one kind of trip. A run as far as Derby, under 15 miles away, is a very different job. So is any distance on the M1, under 3 miles from Lower Birchwood, where the motor has been running hard throughout.
Driven till it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the engine is telling you. Pull up wherever you are — the verge on Piccaver Close, a lay-by, a side street — then leave the car there. The drain and flush-through still come first, and they sort it out: if a car is pulled over early, lasting damage is very unusual.
What Lower Birchwood drivers get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. A bigger tank of the same mixture is all you get, because topping up takes out nothing. Percentage is not how a diesel fuel system copes with petrol, however much that advice assumes.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." Smaller components and higher pressure are the way a newer diesel runs its fuel, and that makes the protection count more, not less.
This is the one that catches motorists. Myth: "If it starts and drives, there is no harm done." A petrol engine fed diesel normally won't run, 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, while your pump grinds. A running engine does not mean fine.
An outdated workaround for a different issue lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It does not put back what petrol has thinned, and that petrol is still in your tank after that.
The next start sends petrol back round your pump from your lines and the filter, where some of it ends up after the motor has been run. That's why draining your tank yourself does not leave you sorted — a myth. Draining petrol into a can at the roadside is also genuinely dangerous.
How does petrol in a diesel take place?
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol car. That's how the forecourt makes it straightforward.
When habit and your car stop matching, it takes place. Courtesy car, hire car, or a vehicle that's new. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps now in a different order. Filling up in a rush on the way to Alfreton, with a train to catch. Exactly the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done.
Next time you fill up around Lower Birchwood: avoiding petrol in a diesel
- The label is what counts, and so check the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- Check your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on the first fill in a car you do not know.
- One of each in the home? Label the key to your diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump. It sounds daft and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put your phone away then keep your mind on the petrol pump.
- Add-on devices are available for motors without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- The moment you realise, stop: less petrol inside that tank makes a thinner blend. What to do next does not change, though — still don't fire it up.
Put petrol in a diesel around Lower Birchwood already?
Short and simple, then, is the order of things. Starting it is out, and so is turning on the ignition. If you're still on the forecourt — The Co-operative or anywhere else — ask the staff to help you push the vehicle clear of the pump. Phone 0333 366 0103 next, with three facts — your fuel, the rough quantity, and if it has run.
If it was AdBlue and not petrol, say so. That's a separate fault — corrosion and deposits rather than lost lubrication — and it has its own page for Lower Birchwood.
What makes one Lower Birchwood petrol in a diesel task cost more than the next
The four situations above are four separate jobs, so no single price for this would be honest. Which of them you are in is chiefly what shifts your cost. After that it's the share — how much petrol got in against how much the tank holds — and after that where the car is and whether a van can reach it safely.
Three questions come first, before any quote, rather than after — what got in, how much, has it run — and this is the reason. Given those answers, you get a straight figure rather than a range.
About Lower Birchwood
Lower Birchwood is a suburban area in Derbyshire, situated approximately 12 miles north of Derby and 120 miles northwest of London. Lower Birchwood sits at an elevation of around 123 metres, characterised by its predominantly semi-detached housing stock. Lower Birchwood is located near other residential areas, including Upper Birchwood and Somercotes, and is part of the wider Derby urban fringe.
Fuel drain cover across Derbyshire, Lower Birchwood included
Petrol in diesel jobs around Lower Birchwood — part of the DE postcode area — go to vans that likewise cover the locations around it, Upper Birchwood, Somercotes and Cotes Park among them. Our technicians drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the pump in Lower Birchwood?
Then you are in the best position there is. Keep it off. Phone.