How Worried Should You Be? Petrol in a Diesel Car in Lostwithiel
Probably less than you already are — provided no one has started the vehicle. Everyone around Lostwithiel starts with "have I ruined it?", and the honest answer is normally no: petrol left in the tank of any diesel remains harmless until priming, cranking or driving draws it into the system. Leave your motor off then ring Petrol in Diesel — that is how you keep it that way. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and the way to make sure you don't repeat it.
The engine and petrol in a diesel: what happens
Diesel does two tasks on its way through an engine. It ignites, and before it burns it protects. Very fine tolerances are built into the injectors and the high-pressure pump, and only your diesel flowing through keeps those surfaces from grinding together.
Of those two tasks, petrol handles the first poorly and the second not at all. The rattling comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the protection your system depends on, and any pump running on such a mix is wearing itself.
Combined, those leave the shape of the issue plain. Not contact but circulation is what does the damage. Where the petrol is only inside that tank, it's a problem of fuel, nothing more. A pump that has been running on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Four situations we see in Lostwithiel: how bad is petrol in a diesel?
Filled up, never started. The best case there is. The petrol is inside your tank and just your tank, and the task is a drain and a flush where the vehicle sits. This is the one situation that can only really occur on a forecourt, since anywhere else the vehicle has been driven to get there.
A moment's running, or merely the ignition on. The fuel system has been bled, so petrol has left that tank and got to the filter and the fuel lines. Drain, flush, deal with your filter: still usually simple.
Driven a few miles. Now the pump has spent those miles running on thinned fuel. Tank, lines, filter, then fresh fuel put through the whole system: that's the work, and the way the vehicle was driven matters as much as the mileage. Short trips, like the school run to Lostwithiel School, are one matter. A run as far as Truro, under 25 miles away, is a very different job. So is any mileage on the M5, over 50 miles from Lostwithiel, where the engine has been working hard throughout.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. What you are hearing is the motor signalling fuel that no longer runs like diesel. Whether it is the verge on Fore Street, a lay-by or a side street, stop there and leave it. A vehicle stopped soon very rarely has permanent damage, since the drain and the flush-through, which still go first, sort it out.
Petrol in a diesel stories Lostwithiel motorists hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. A bigger tank of the same mix is all you get, since topping up takes out nothing. Percentage is not how a diesel fuel system copes with petrol, whatever that advice supposes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A newer diesel runs its fuel through smaller components at higher pressure, which makes the protection count more, not less.
Myth: "If it starts and drives, there is no harm done." This is the one that fools drivers. Any petrol engine fed diesel normally won't run, and 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 the pump grinds. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a distinct fault. None of what petrol diluted gets put back by it — and afterwards, your tank still contains that petrol.
Myth: "Drain that tank yourself and you're sorted." Once your engine has been run, some of that petrol is no longer in the tank: it is in the fuel filter and your lines, and it goes straight back through your pump at the next start. It's also genuinely risky to drain petrol into a can by the kerbside.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. A diesel nozzle mostly won't go into a petrol vehicle, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and only in one direction.
The moment routine stops matching the car is the moment it takes place. Any motor that is new to you — a hire car, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. Fuelling up in a hurry on the way to the nearest station, with a train to catch. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Your hand does what it has always done when you add rain, a phone call or a back seat full of children.
Lostwithiel drivers: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is just a hint.
- Inspect your filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on the first fill in any motor you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a household has one of each. So label it.
- Before the nozzle comes off the petrol pump the first time you fill a hired or new vehicle, say "diesel" out loud. Silly, yes, but it works.
- Mistakes like this are simple to make whilst your mind is on something else, and so your phone goes away.
- Some diesels come with a filler designed to block a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- Stop the moment you notice. Less petrol in the tank means a weaker blend. It doesn't change what to do next, which is still not to crank it.
Lostwithiel: already put petrol in a diesel?
Then the order of things is short. Never start the car, and don't turn the ignition on. The attendants at the forecourt — whether at Gulf itself or wherever you filled up — will usually help push it away from the pump if you ask. What went in, about how much, and whether it has run: tell us that when you ring 0333 366 0103.
If it was AdBlue rather than petrol, say so. That is a different fault — corrosion and deposits and not lost lubrication — and it has its own page for Lostwithiel.
What makes one Lostwithiel petrol in a diesel task cost more than the next
The four situations above are four separate tasks, so no single quote for this would be fair. What moves your cost is mostly which of them you are in. After that it is the ratio — how much petrol was put in against how much the tank holds — and then where the vehicle is and whether our van can get to it safely.
Three queries come first, before any quote, rather than after — what went in, how much, has it run — and that is the reason. Those answers are what turn a range into one firm number.
About Lostwithiel
Lostwithiel is a town situated on the banks of the River Fowey in Cornwall, with a population of around 3067 people. Lostwithiel has a mix of housing types, but detached homes are the most common, and its low elevation of 13 metres above sea level reflects its riverside setting. Lostwithiel is located near several smaller communities, including Bridgend, Downend, and No Mans Land, and is within a short drive of the city of Truro. Lostwithiel remains a small but distinct town in the Cornish countryside, about 211 miles west of London.
Lostwithiel and Cornwall: where our fuel drain cover reaches
Bridgend, Downend and No Mans Land are among the spots around Lostwithiel that the same vans work, answering petrol in diesel call-outs across Lostwithiel's PL postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our technicians drain, and your vehicle doesn't need to come to us.
Still at the pump around Lostwithiel?
Then you're in the best place there is. Turned off it stays; then phone.