Should You Worry? Petrol in a Diesel Car in Wellow
Far less than you likely are, provided it has not been started. Petrol resting in a diesel tank does nothing to the motor until something draws it through the fuel system — the ignition priming your pump, the starter, or driving on its own. So the fair answer to the first query anyone around Wellow asks, "have I ruined it?", is usually no. To keep it that way, call Petrol in Diesel and leave the motor alone. Read on for three things: the effect petrol has inside a diesel engine, 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 really does
Passing through an engine, diesel is doing two things at the same time. Before it combusts, it protects — and then it ignites. Extremely fine gaps go into the fuel injectors and the high-pressure fuel pump, and just your diesel flowing through stops those surfaces grinding together.
Petrol does the first task poorly and the second not at all. A pump working on a petrol blend is wearing itself out, since petrol is runnier than diesel and takes away the protection 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 the rattling starts.
Combined, those leave the shape of the problem plain. Contact doesn't do the harm — movement does. All a tank with petrol in it amounts to is a fuel issue. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Wellow, petrol in a diesel: four cases, from mild to serious
Fuelled up, not once started. The best case there can be. At a forecourt, and really only there, the petrol is still confined to that tank — because everywhere else the vehicle was driven to get to it. The task is emptying and cleaning on the spot.
Started for a moment, or just your ignition on. The fuel system has been primed, so petrol has left the tank and got to your filter and the lines. Drain, flush, see to your filter: still normally simple.
Driven a few miles. Now your pump has spent these miles labouring on weakened fuel. Distance is only half of it; how hard it was driven matters equally. Either way the work runs to your tank, the fuel lines, the filter and clean fuel through the whole circuit. On the school run to Welholme Academy, the distance is short. Very different a second time: a trip to Kingston upon Hull, under 25 miles away, or some mileage on the M180, under 15 miles from Wellow, where the engine never stopped running hard.
Driven on until it complained — rattling, smoke, a lumpy idle, a dead throttle. That's the motor telling you its fuel has stopped acting like diesel. Leave it where it stops: a lay-by, a side street, the verge on Park Drive. What comes first is still the fuel drain and flush, and that takes care of it, with permanent damage very uncommon if a car is stopped quickly.
What Wellow drivers get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mix is all you get, since topping up removes nothing. A diesel fuel system does not tolerate petrol by percentage in the way that guidance assumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. Protection counts more on newer diesels, not less, since their fuel passes through finer components at higher pressure.
"It starts, it drives, so there is no harm" — the myth that trips up most motorists than any other. A petrol engine fed diesel usually won't run, and so the driver stops and the damage stops with them. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, while your pump grinds. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive it home." It is an outdated fix for a separate fault. None of what petrol diluted gets put back by it — and later, that tank still contains that petrol.
Once the engine has run, part of the petrol is in your filter and the lines, not that tank — and your next start pulls it straight back through your pump. So the myth "drain your tank yourself and you are sorted" does not stand up. And, a can of petrol filled by the roadside is truly risky.
How it happens: petrol in a diesel
Nobody does it on purpose, and it is seldom carelessness. One way only, because of the nozzles: the narrower petrol one slides 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 simple.
Habit and the vehicle getting out of step is how it takes place. Courtesy car, hire car, or a car that is brand new. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a well-known forecourt. A hurried fill on the way to Grimsby Town with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: precisely when it happens. Throw in a back seat full of children, a phone call or rain, and habit wins.
Wellow people: how to avoid petrol in a diesel next time
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in an unfamiliar car is the time to check the filler flap — inside 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 home has one of each. So label it.
- Before the nozzle comes off the pump the first time you fill a hired or new car, say "diesel" aloud. Daft, perhaps, but it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and aftermarket devices are available for the remainder. Count it as a backstop, then keep reading the petrol pump.
- Less petrol makes a thinner mixture, and so stop as soon as you notice — while remembering that your next stage is unchanged. It's still not to start the vehicle.
Petrol already in a diesel around Wellow? Begin here
The order of things is brief, then. Do not switch the ignition on, and don't start it. Still on the forecourt, at Asda or anywhere else? Ask the attendants to help you roll it clear of the pump. Next, 0333 366 0103. We will ask what got in, roughly how much, and if it has been run.
Say so if it was AdBlue instead of petrol: it's a different issue, with its own page for Wellow, since AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel task around Wellow costs more than another. Why?
Four separate tasks lie behind the four situations above — which is why there's no fair single quote. Chiefly, your cost shifts with which one you're in. Next it is the share — how much petrol was put in against how much your tank holds — and then where the vehicle is and whether a technician can get to it safely.
Three questions come first, before any quote, instead of after — what was put in, how much, has it run — and that is the reason. Those replies are what turn a range into one firm number.
About Wellow
Wellow is a suburban area in northern Lincolnshire, situated near the coast and approximately 16 miles from Kingston upon Hull. Wellow has a relatively low elevation of around 7 metres above sea level, and its location near the Humber Estuary has influenced its development. Wellow is characterized by its predominantly terraced housing stock, reflecting its history of residential growth in the region.
Fuel drain cover across Lincolnshire, Wellow included
Grimsby, Holme Hill and Weelsby are among the spots around Wellow that the same teams work, answering petrol in diesel calls across Wellow's DN postcode area. You need not move the car to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots we drain.
At the petrol pump in Wellow, still?
Nothing beats it: that is where you now are. Keep it off. Call.