Petrol in a Diesel Car in New Lanark: How Worried Should You Be?
Provided it has not been started, you can worry far less than you likely are. Until your ignition primes your pump, your starter cranks, or your car is driven, petrol in a diesel tank simply rests there and does nothing. Which makes the truthful reply to the first New Lanark question — "have I wrecked it?" — normally no. Keep it like that: leave your motor off then call Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has spread, and ways to make sure you never do it again.
Inside the engine: what petrol in a diesel does
Passing through a motor, diesel does two things at the same time. Oiling comes before burning; it does both. What keeps the surfaces inside your high-pressure pump and the fuel injectors from grinding against each other is your diesel flowing through them — they are built to extremely fine clearances.
Petrol handles the first task badly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is runnier than diesel and takes away the lubrication the fuel system depends 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.
The shape of the trouble is clear when you put those together. Not contact but circulation is what causes the harm. Where that petrol is only in the tank, it's an issue of fuel, nothing more. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the fuel injectors downstream.
New Lanark, petrol in a diesel: four situations, from mild to serious
Fuelled up, never started. The best case there can be. Only the tank has petrol in it, and so the job is clearing your tank and cleaning the system where the car sits. This scenario can only truly occur at a forecourt: anywhere else, the vehicle got there by being driven.
The ignition turned on, or a short start. With your system primed, the fuel lines and filter now hold petrol that came from that tank. Usually nothing more than draining, flushing and seeing to the fuel filter, and so still easy.
Those few miles on the road meant your pump running on fuel diluted by petrol the whole way. Distance is only half of it; how hard it was driven counts equally. Either way the work runs to your tank, the fuel lines, the fuel filter and fresh fuel through the entire circuit. Driving the kids to the local primary school is one kind of trip. Getting as far as Glasgow, under 25 miles away, makes a very different job — as does any distance on the M74, under 5 miles from New Lanark, with the motor labouring hard the whole time.
Driven on until it complained — clattering, smoke, an uneven idle, a dead throttle. The engine is telling you the fuel is no longer acting like diesel. Leave it where it has stopped: a lay-by, a side street, the verge on Rosedale Street. The drain and flush-through still go first, and they deal with it: if a vehicle is pulled over soon, long-term damage is very rare.
Petrol in a diesel stories New Lanark motorists hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. Nothing is removed by topping up — you're left with a fuller tank, still the same mix. Percentage is not how a diesel fuel system tolerates petrol, whatever that guidance supposes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. Smaller parts and higher pressure are the way a newer diesel runs its fuel, and that makes the protection matter more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Diesel in a petrol motor generally means a motor that will not run: the motorist stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Fine and running are not the same at all.
Myth: "Add some two-stroke oil and drive it home." It's an outdated workaround for a separate issue. What petrol has weakened stays thinned, and the petrol stays in the tank regardless.
The next start sends petrol back round the pump out of the lines and the filter, where some of it ends up after your engine has run. That's why draining the tank yourself does not leave you sorted — a myth. Besides, petrol drained into a can by the road is genuinely risky.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
It happens when habit and your car stop matching. A car that's new to you — hired, on loan as a courtesy car, or brand new. One petrol and one diesel on the driveway of the same household. A familiar forecourt with the pumps in a different order. Fuelling up in a rush on the way to Lanark, with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it takes place. Add rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
Next time you fill up around New Lanark: avoiding petrol in a diesel
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the pump, not the colour.
- The first fill in a strange vehicle is the time to check the filler flap — on it, or on the cap, many motors state the fuel to use.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key when a household has one of each. So label it.
- It seems silly and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Mistakes like this are easy to make whilst your mind is on something else, so your phone goes away.
- Some diesels come with a filler built to refuse a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the pump.
- As soon as you notice, stop: less petrol in your tank means a thinner mix. What to do next does not change, though — still do not fire it up.
New Lanark: already put petrol in a diesel?
Then, there is only a short order of things. Do not crank it, and don't switch the ignition on. Still on the forecourt, at Esso or anywhere else? Ask the attendants to help you push the vehicle clear of the pump. What got in, about how much, and if it's run: tell us that when you ring 0333 366 0103.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own New Lanark page.
Why one petrol in a diesel task around New Lanark costs more than another
There's no honest single quote for this, because the four situations above are four different tasks. Chiefly, the cost shifts with which situation you're in. Next it is the proportion — how much petrol went in against how much your tank takes — and then where the car is and whether our van can reach it safely.
Before any quote, not after, come three questions: your fuel that was put in, its quantity, and if it has run. That's why. Those answers are what turn a range into one firm number.
About New Lanark itself
New Lanark is a small suburban area situated on the banks of the River Clyde in South Lanarkshire, with a mix of flat housing and scenic riverside views. New Lanark sits at an elevation of around 130 metres, near the town of Lanark and other nearby places such as Kingsons Knowe and Kirkfieldbank. New Lanark is located approximately 22 miles southeast of Glasgow, making it a relatively accessible residential area. New Lanark has a population of around 610 people, living in a predominantly flat-based community.
Fuel drain cover across South Lanarkshire, New Lanark included
Kingsons Knowe, Lanark and Kirkfieldbank are among the places near New Lanark that the same vans work, answering petrol in diesel jobs across New Lanark's ML postcode area. No need to bring your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
In New Lanark and still at the pump?
Then you are in the best place there can be. Turned off it stays; then ring.