Petrol in a Diesel Car in The Pound: How Worried Should You Be?
Likely less than you are now — as long as nobody has started the vehicle. Petrol resting in a diesel tank does nothing to the engine till something draws it through the fuel system — the ignition priming your pump, the starter, or driving on its own. So the truthful answer to the first query anyone in The Pound asks, "have I ruined it?", is usually no. To leave the car like that, ring Petrol in Diesel then leave the motor switched off. The remainder of this page covers what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
Petrol in a diesel: what does it do to the engine?
Two tasks fall to diesel on its journey round a motor. Lubricating comes before burning; it does both. The high-pressure pump and the fuel injectors are built to very fine gaps, and your diesel passing through them is what stops those surfaces from wearing down against one another.
Petrol does the first task poorly and the second not at all. A pump running on a petrol mix is wearing itself out, because petrol is thinner 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 needs from its fuel — and that is where the clattering comes.
The shape of the issue is plain once you put those together. Not contact but movement is what causes the damage. A tank with petrol in it is a fuel problem. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
The Pound, petrol in a diesel: four cases, from mild to significant
The best case there can be: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol held in the tank alone, it is drained and cleaned on the spot, and nothing more is needed.
Ignition on, or started for a moment. With the fuel system primed, the lines and filter already hold petrol that came from your tank. That's normally still a straightforward task — a drain, a flush, and the fuel filter seen to.
A few miles driven, and your pump has spent every one of them labouring on thinned fuel. How hard your car was driven matters as much as how far, and this work covers that tank, your lines, the fuel filter and clean fuel through the entire circuit. The school run to East Peckham Primary School is one matter. A run as far as Southend-on-Sea, under 50 miles away, is a very different job. So is any mileage on the M26, under 10 miles from The Pound, where the motor has been labouring hard the whole time.
Driven on until it complained — knocking, smoke, a lumpy idle, a soft throttle. The motor is telling you the fuel is no longer behaving like diesel. Stop on the spot — on the verge on Fell Mead, at the kerb, down a side road — and don't move it. A car stopped quickly very rarely has lasting damage, since the drain and the flush-through, which still go first, take care of it.
Stories The Pound drivers hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing comes out when you top up — your tank simply holds more of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice presumes.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." A newer diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
"It starts, it drives, so there is no harm" — the myth that catches more drivers than any other. Any petrol motor fed diesel generally will not run, and so the motorist stops and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, whilst the pump grinds. Being able to run is not the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. What petrol has diluted stays thinned, and the petrol remains inside your tank anyway.
The next start draws petrol back round the pump out of your lines and the fuel filter, where some of it sits once the engine has run. That's why draining your tank yourself doesn't sort it — a myth. Emptying petrol into a can by the roadside is also genuinely hazardous.
How does petrol in a diesel take place?
On purpose? Never. Through carelessness? Rarely, if ever. One way only, since of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol car. That's how the forecourt makes it straightforward.
It takes place when routine and your car stop matching. Courtesy car, hire car, or a vehicle that is new. Households running one of each, petrol and diesel. Your ordinary forecourt, its pumps now in a different order. A hurried fill on the way to Beltring with a train to catch. Years of petrol motors behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Preventing petrol in a diesel next time you fill up in The Pound
- A green handle for unleaded and black for diesel is normal in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of motors state the fuel inside the filler flap or on the cap, so check it on your first fill in any car you don't know.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- It seems silly and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and aftermarket devices are available for the rest. Count it as a safety net, and keep checking the petrol pump.
- Spotting it mid-fill? Stop at once. A thinner blend follows from less petrol in your tank, but your next stage stays the same: don't fire it up.
Already put petrol in a diesel around The Pound?
Then, there's just a short order of things. Starting it is out, and so is turning on your ignition. If you are still at the forecourt — the nearest petrol station or anywhere else — ask the attendants to help you push the vehicle away from the pump. Ring 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and if it's run.
Say so if it was AdBlue rather than petrol: it's a different problem, with its own page for The Pound, since AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel task in The Pound costs more than another
There's no honest single price for this, because the four situations above are four different tasks. Which of them you're in is chiefly what shifts your cost. The ratio counts next, meaning how much of the tank is petrol, followed by the position of the car and whether reaching it is safe for a technician.
Three questions come first, before quoting, rather than after — what was put in, how much, has it run — and that is the reason. Those replies are what change a range into one firm number.
About The Pound
The Pound is a suburban area situated on the riverside in Kent, with an elevation of around 14 metres. The Pound lies near several small settlements, including East Peckham and Addlestead, and is characterized by its semi-detached housing stock. The Pound is located approximately 30 miles from London and 26 miles from Southend-on-Sea, making it a commuter base for those working in larger cities. The Pound has a population of around 2453 residents.
Fuel drain cover in The Pound and across Kent
Petrol in diesel calls in The Pound — part of the TN postcode area — go to vans that also cover the locations about it, East Peckham, Snoll Hatch and Addlestead among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our technicians work, and your car doesn't need to move to us.
The Pound: still at the petrol pump?
No position is better: that's where you are. Keep it off. Call.