Should You Worry? Petrol in a Diesel Car in Blackridge
Provided it hasn't been started, you can worry less than you likely are. Until the ignition primes your pump, the starter cranks, or the car is driven, petrol in a diesel tank simply sits there and does nothing. Which means the truthful reply to the first Blackridge query — "have I ruined it?" — usually no. Keep it that way: leave the engine off and phone Petrol in Diesel. Below, you will find what petrol really 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?
Two tasks fall to diesel on its route through a motor. It protects first, and only then does it burn. Very fine gaps go into the fuel injectors and your high-pressure pump, and only your diesel flowing through stops those surfaces grinding together.
Badly at the first, not at all at the second: that's petrol. A pump running on a petrol mix is wearing itself out, since petrol is thinner than diesel and takes away the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where any knocking comes.
The shape of the issue is clear when you put those together. Not contact but movement is what does the harm. Any tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, carried by the fuel, into the injectors further along, which is why a pump that has worked on that petrol is where a mechanical problem starts.
Four situations our engineers see around Blackridge: how serious is petrol in a diesel?
Fuelled but not once started — the best it gets. The petrol is inside that tank and just that tank, and the job is a drain and a flush where the vehicle stands. This is the one situation that can only really take place at a forecourt, because anywhere else your car has been driven to get there.
A moment's running, or just the ignition on. Your system has been bled, and so petrol has left that tank and got to the filter and the fuel lines. That's generally still a straightforward job — a drain, a flush, and the fuel filter seen to.
Driven a couple of miles. Now the pump has spent these miles working on diluted fuel. Mileage is only half of that; how hard it was driven counts equally. Either way the work runs to your tank, the lines, the filter and clean fuel through the whole system. A school run to the local primary school is one matter. A run as far as Stirling, under 25 miles away, is a very different job. So is any mileage on the M8, under 3 miles from Blackridge, where the motor has been running hard the whole time.
Driven on till it protested — rattling, smoke, an uneven idle, a dead throttle. The fuel isn't behaving like diesel any more, and the motor is saying so. Stop wherever you are — the verge on Louburn, a lay-by, a side street — then leave the car there. Long-term damage is very uncommon if a car is pulled over quickly, and the drain and flush-through that still go first deal with it.
What Blackridge 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 will not. Topping up removes nothing; it gives you a fuller tank of the same mix. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance assumes.
If anything, the opposite holds. Myth: "A newer diesel can cope with a bit of petrol." Lubrication matters more on current diesels, not less, because their fuel runs through more precise parts at higher pressure.
The myth that catches motorists out: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it normally won't run, and so the motorist stops — and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, whilst your pump grinds. Fine and running are not the same thing.
An old fix for a distinct issue lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It doesn't put back what petrol has diluted, and the petrol is still inside the tank later on.
The next start draws petrol back round the pump from the fuel lines and your filter, where some of it ends up after your engine has run. That's why a DIY tank drain does not leave you sorted — a myth. Emptying petrol into a can by the kerbside is also really hazardous.
Petrol in a diesel: how does it take place?
Nobody does it on purpose, and it is seldom carelessness. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol motor at all. The forecourt makes it easy, and the slip runs one way.
The moment routine stops matching the car is the moment it takes place. Hire cars, courtesy cars, and motors that are new to you. Two motors on one driveway, one petrol, one diesel. Your ordinary forecourt, its pumps suddenly in a different order. A hurried fill en route to the nearest station with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it takes place. The hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up around Blackridge: avoiding petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Trust the label on the pump, not the colour.
- The first fill in an unfamiliar motor is the time to check your filler flap — inside it, or on the cap, plenty of vehicles state which fuel they take.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, for a house with one of each.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems silly and it works.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to refuse a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop checking the petrol pump.
- Stop the moment you realise. Less petrol inside the tank means a weaker mixture. It doesn't change what to do next, which is still not to fire it up.
Petrol already in a diesel around Blackridge? Begin here
Short and simple, then, is the order of things. Don't start it, and do not switch the ignition on. If you are still at the forecourt — BP or anywhere else — ask the staff to help you push the vehicle away from the petrol pump. What was put in, roughly how much, and whether it's run: tell us those when you ring 0333 366 0103.
Say so if it was AdBlue instead of petrol: it's a different fault, with its own page for Blackridge, since AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task around Blackridge costs more than another
There's no fair single price for this, because the four situations above are four different jobs. The scenario itself does most of the work of moving your cost. Two things come after that: the petrol that was put in as a share of what that tank holds, then the spot your car is in and whether a van can reach it safely.
Ahead of any quote, not after, we ask three questions: the fuel that got in, the quantity, and whether it has run. That's why. Those answers turn a range into a straight figure.
About Blackridge itself
Blackridge is a village in West Lothian, situated on the riverside at an elevation of 184 metres. Blackridge has a population of around 1221 people and is characterised by predominantly detached housing. Blackridge is located near several other small communities, including Westrigg, Harthill, and Eastfield, and is within commuting distance of Stirling, which is 17 miles away.
Blackridge and West Lothian: where our fuel drain cover reaches
The teams answering petrol in diesel jobs around Blackridge, in the EH postcode area, equally work the places near it, Westrigg, Harthill and Eastfield included. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our technicians work, and the car does not need to move to us.
Still at the pump around Blackridge?
In that case, you couldn't be in a better position. Keep the vehicle switched off, and ring.