Should You Worry? Petrol in a Diesel Car in Moggerhanger
Provided it hasn't been started, worry less than you likely are. Everyone around Moggerhanger starts with "have I wrecked it?", and the fair answer is usually no: petrol resting inside the tank of a diesel remains harmless till priming, cranking or driving pulls it into the system. Keep it like that: leave your motor off and phone Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the signs of how far it has spread, and ways to make sure you never repeat it.
Inside your engine: what petrol in a diesel does
Two tasks fall to diesel on its journey through a motor. It burns, and before it ignites it protects. What stops the surfaces inside the high-pressure pump and the injectors from grinding against each other is the diesel flowing through them — they're made to extremely fine clearances.
Petrol does the first job badly and the second not at all. The rattling comes from petrol being designed not to ignite when compressed, which is exactly 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 such a blend is wearing itself.
Seen together, they make clear what shape the problem has. It is movement that causes the damage, not contact. Any tank with petrol in it is a fuel problem. Whatever a worn pump sheds goes on, borne by the fuel, into the fuel injectors further along, which is why a pump that has been working on that petrol is where a mechanical issue begins.
Petrol in a diesel in Moggerhanger: how bad is it? Four situations
Fuelled but not once started — the best it gets. On a forecourt, and truly only there, the petrol is still limited to that tank — because everywhere else your car was driven to reach it. The job is draining and purging on the spot.
A brief spell of running, or merely your ignition on. With the fuel system primed, the fuel lines and filter already hold petrol that has come from your tank. Usually little more than emptying, purging and seeing to the fuel filter, and so still straightforward.
Your pump has worked a few miles on weakened fuel — that's what driving the car does. How hard the vehicle was driven counts as much as how far, and the work takes in your tank, your lines, your filter and fresh fuel through the whole system. Short trips, such as the school run to Moggerhanger Primary School, are one matter. A run as far as Milton Keynes, under 25 miles away, is a very different task. So is any miles on the A1(M), under 10 miles from Moggerhanger, where the engine has been running hard the whole time.
Driven till it complained. Clattering, an uneven idle, smoke, a throttle that has gone soft. That's the motor telling you its fuel no longer is acting like diesel. Stop where you are — on the verge on West Way, at the kerb, down a side road — and do not move it. A vehicle stopped soon very rarely has long-term damage, because the drain and the flush, which still come first, take care of it.
Moggerhanger motorists and that petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up removes nothing; it gives you a bigger tank of the same mixture. Percentage isn't how a diesel fuel system copes with petrol, however much that guidance presumes.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. A current diesel sends its fuel through smaller parts at higher pressure, which makes the lubrication matter more, not less.
The myth that catches motorists out: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it normally will not run, so the driver stops — and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump wears. Running doesn't mean fine.
An outdated fix for a separate issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." That petrol is still in your tank after that, and whatever it has diluted isn't put back.
Myth: "Drain that tank yourself and you are sorted." After your engine has been run, some of that petrol is no longer inside the tank: it's in the filter and the lines, and it goes right back through your pump at your next start. On top of that, petrol drained into a can by the road is genuinely dangerous.
How does petrol in a diesel happen?
It is rarely carelessness, and nobody does it on purpose. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol motor. That's how the forecourt makes it straightforward.
Routine and the vehicle falling out of step is how it happens. Any vehicle that is new to you — hired, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. Fuelling up in a hurry en route to Sandy, with a train to catch. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Add rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Moggerhanger motorists: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a hint.
- Check the filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you do not know.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key if a home has one of each. So mark it.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" out loud. Silly, yes, but it does the trick.
- Mistakes like this are easy to make whilst your mind is on something else, so the phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler built to refuse 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.
- Spotting it mid-fill? Stop at once. A thinner mixture results from less petrol inside your tank, but the next stage remains the same: do not fire it up.
Moggerhanger: already put petrol in a diesel?
Short and simple, then, is the order of things. Leave it unstarted, with your ignition switched off as well. Ask the attendants to help you roll it clear of the pump if you're still on the forecourt, whether that is Texaco or somewhere else. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Say so if it was AdBlue rather than petrol: it's a separate fault, with its own page for Moggerhanger, because AdBlue brings corrosion and deposits rather than lost protection.
One petrol in a diesel job in Moggerhanger costs more than another. Why?
There is no fair single price for this, because the four scenarios above are four separate jobs. Which of them you're in is chiefly what moves the cost. Two things come after that: the petrol that got in as a share of what the tank takes, then the place the vehicle is in and whether a technician can reach it safely.
That is why our engineers ask three queries before costing instead of after: what went in, how much, and whether it has run. Those replies change a range into a straight figure.
About Moggerhanger, briefly
Moggerhanger is a small village in Bedfordshire, situated in a rural area with a mix of arable farmland and woodland. Moggerhanger lies near the villages of Chalton and Blunham, and is characterized by its detached housing stock. Moggerhanger is located approximately 47 metres above sea level, and is about 18.9 miles from Milton Keynes. Moggerhanger has a population of around 672 residents.
Moggerhanger and Bedfordshire: where our fuel drain cover reaches
Chalton, Thorncote Green and Blunham are among the places near Moggerhanger that the same vans work, answering petrol in diesel calls across Moggerhanger's MK postcode area. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
At the pump around Moggerhanger, still?
The best spot there is, then — that is where you are. Turned off it stays; then call.