Should You Worry? Petrol in a Diesel Car in Watford Park
Far less than you probably are, provided it has not been started. "Have I wrecked it?" is the first thing anyone in Watford Park asks, and the honest answer is generally no, because petrol resting in a diesel tank harms nothing until it's drawn through the fuel system — by ignition priming, by your starter, or by being driven. Keep it that way: leave your motor off then ring Petrol in Diesel. The rest of this page sets out what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you a second time.
What petrol in a diesel does to your engine
Diesel has two tasks on its way through an engine. It burns, and before it burns it lubricates. Very fine tolerances are built into the injectors and the high-pressure fuel pump, and just your diesel flowing through stops those surfaces grinding together.
Badly at the first, not at all at the second: that's petrol. It is runnier than diesel and takes away the lubrication the system hinges on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Combined, those leave the shape of the trouble clear. Contact doesn't do the damage — movement does. Any tank with petrol in it is a fuel issue. 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 the fuel to the injectors beyond it.
Watford Park, petrol in a diesel: four situations, from mild to significant
Filled up, and not started: nothing beats it. The petrol is inside that tank and just that tank, and the task is a drain and a flush where the vehicle stands. This is the one scenario that can only really take place on a forecourt, since anywhere else the vehicle has been driven to get there.
Ignition on, or started for a moment. Once primed, your system has drawn petrol out of the tank as far as your filter and the lines. Usually little more than emptying, cleaning and seeing to the fuel filter, so still easy.
A few miles driven, and the pump has spent each of them labouring on thinned fuel. How hard your car was driven counts as much as how far, and the work covers your tank, the fuel lines, your filter and clean fuel through the whole circuit. The school run to the local primary school is one thing. Any miles on the M4, under 3 miles from Watford Park, means the engine working hard throughout, and a run to Cardiff, under 10 miles away, is a very different task as well.
Driven until it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer behaving like diesel. Stop wherever you are — the verge on Ffordd Traws Cwm, a lay-by, a side street — and leave it there. Permanent damage is very rare if a car is pulled over soon, and the fuel drain and flush that still go first deal with it.
Watford Park motorists and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Topping up removes nothing; it gives you a bigger tank of the same mixture. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a modern diesel copes with a bit of petrol. If anything, the reverse. A modern diesel runs its fuel through more precise parts at higher pressure, which makes the lubrication count more, not less.
"It starts, it drives, and so there is no harm" — the myth that trips up more motorists than any other. Diesel in a petrol motor usually leaves 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, as it usually does; meanwhile the pump grinds. Being able to run is not the same as being fine.
An outdated workaround for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still in that tank afterwards, and whatever it has thinned is not put back.
Myth: "Drain your tank yourself and you're sorted." Once the engine has been run, some of the petrol is no longer inside that tank: it's in the filter and your lines, and it goes right back through the pump on the next start. Clearing petrol into a can by the roadside is also really risky.
Petrol in a diesel: how does it occur?
It is seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally will not go into a petrol motor at all. So the error runs one way.
The moment habit stops matching your car is the moment it takes place. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the driveway. Your ordinary forecourt, its pumps now in a different order. A train to catch, and a rushed fill on the way to Aber. The first fill-up in a diesel Renault Clio after years of driving petrol is exactly the moment it occurs. Add a back seat full of children, a phone call or rain, and the hand wins.
Next time you fill up in Watford Park: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Read the pump's label; the colour is only a clue.
- Inspect the filler flap. Plenty of motors state the fuel inside the flap or on the cap. Look at it on your first fill in a vehicle you don't know.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a household has one of each. So mark it.
- It seems silly and it works: on your 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 simple to make while your mind is on something else, so the phone goes away.
- Some diesels have a filler designed to reject 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.
- Stop the moment you realise. Less petrol in your tank means a weaker blend. It does not change what to do next, which is still not to start it.
Put petrol in a diesel around Watford Park already?
Then, there's just a short order of things. Leave it unstarted, with the ignition off as well. If you are still at the forecourt — BP or anywhere else — ask the attendants to help you push the car away from the pump. Call 0333 366 0103 next, with three answers — your fuel, the rough volume, and if it's run.
If it was AdBlue instead of petrol, say so. That's a different issue — corrosion and deposits instead of lost lubrication — and it has its own page for Watford Park.
One petrol in a diesel task in Watford Park costs more than another. Why?
The four situations above are four separate jobs, so no single price for this would be fair. Chiefly, the cost shifts with which one you're in. Two things come after that: the petrol that got in as a proportion of what the tank holds, then the place the vehicle is in and whether our van can get to it safely.
What went in, how much, and whether it's run — three questions we ask before quoting, not after, for exactly that reason. A range becomes a straight figure when those answers are in.
About Watford Park, briefly
Watford Park is a suburban area in Caerphilly, situated near the riverside with an elevation of around 115 metres. Watford Park lies close to the nearby places of Glenfield Estate, Bondfield Park, and Trecenydd, and is approximately 6.9 miles from Cardiff. Watford Park has a population of around 4910 people and is characterised by predominantly detached housing.
Fuel drain cover across Caerphilly, Watford Park included
Glenfield Estate, Bondfield Park and Trecenydd are among the locations around Watford Park that the same vans work, answering petrol in diesel jobs across Watford Park's CF postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers work, and the car does not need to move to us.
At the petrol pump in Watford Park, still?
Then you're in the best place there is. Ring, and leave it switched off.