Should You Worry? Petrol in a Diesel Car in Portesham
Probably less than you are now — as long as no one has started the vehicle. Till the ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank just rests there and does no harm. Which means the truthful reply to the first Portesham question — "have I wrecked it?" — usually no. Leave the motor off then phone Petrol in Diesel — that keeps it like that. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you don't do it again.
What petrol in a diesel does to your engine
Two tasks fall to diesel on its journey through a motor. Lubricating comes before burning; it does both. The high-pressure pump and your injectors are designed to extremely fine gaps, and your diesel passing through them is what stops those surfaces from wearing down against one another.
Badly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump running on the blend to wear itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
Put these together and the shape of the issue is plain. It's movement that causes the harm, not contact. Where that petrol is only inside the tank, it's a fault of fuel, nothing more. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors downstream.
Petrol in a diesel around Portesham: how bad is it? Four situations
Fuelled, and not started: no case is better. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol kept inside that tank alone, it's emptied and purged on the spot, and nothing more is needed.
Started for a moment, or only the ignition on. Your system has been primed, and so petrol has left your tank and reached the filter and your lines. Drain, flush, deal with the fuel filter: still normally easy.
Some miles driven, and the pump has spent each of them labouring on diluted fuel. The work is that tank, your lines, the fuel filter and fresh fuel through the entire system, and how hard the car was driven counts as much as how far. Short trips, such as the school run to Portesham Church of England Primary School, are one thing. Very different a second time: a trip to Wells, under 50 miles away, or some distance on the M5, under 50 miles from Portesham, where the motor never stopped working hard.
Driven until it complained. Rattling, an uneven idle, smoke, a throttle that has gone soft. That is your motor telling you its fuel no longer is behaving like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Church Lane. The fuel drain and flush-through still go first, and they deal with it: if a vehicle is stopped quickly, long-term damage is very rare.
What Portesham drivers get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up takes out nothing; it gives you a bigger tank of the same mix. The assumption behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A modern diesel can cope with a bit of petrol." A newer diesel runs its fuel through smaller parts at higher pressure, which makes the protection count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there is no harm done." The motorist of a petrol engine fed diesel usually has no choice but to stop, because it will not run, and the damage stops with them. A diesel fed petrol generally starts, idles and drives away as if nothing has happened, while the pump grinds. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different fault. The petrol is still in that tank after that, and what it has diluted is not put back.
The next start sends petrol back round the pump out of the fuel lines and your filter, where some of that sits after the motor has run. That is why a DIY tank drain does not sort it — a myth. It's also truly dangerous to drain petrol into a can by the kerbside.
How does petrol in a diesel happen?
On purpose? Never. Through carelessness? Rarely, if ever. One way only, because of the nozzles: the narrower petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol motor. That is how the forecourt makes it simple.
Routine and the vehicle falling out of step is how it occurs. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a familiar forecourt. A train to catch, and a hurried fill en route to Upwey. Precisely the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Throw in rain, a phone call or a back seat full of children, and the hand does what it has always done.
Next time you fill up in Portesham: avoiding petrol in a diesel
- Read the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what counts.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: many vehicles print the fuel there.
- Label your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" aloud. Daft, yes, yet it does the trick.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to block a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a safety net, and keep checking the petrol pump.
- Spotting it halfway? Stop there and then. A thinner blend results from less petrol in your tank, yet the next stage stays the same: don't start the car.
Already put petrol in a diesel around Portesham?
In that case, there is just a short order of things. Starting it is out, and so is switching on the ignition. If you're still at the forecourt — Esso or anywhere else — ask the staff to help you roll it clear of the pump. What was put in, about how much, and if it has run: tell us those when you call 0333 366 0103.
If it was AdBlue rather than petrol, say so. That is a separate fault — corrosion and deposits and not lost protection — and it has its own page for Portesham.
Why one petrol in a diesel job in Portesham costs more than another
The four scenarios above are four separate tasks, so no single quote for this would be fair. Which of them you're in is mostly what moves the cost. Two things follow that: the petrol that got in as a proportion of what the tank takes, then the place your car is in and whether our van can get to it safely.
Three queries come first, before quoting, rather than after — what was put in, how much, has it run — and that is the reason. Their answers are what turn a range into one firm number.
About Portesham itself
Portesham is a small village in south Dorset, situated near the coast at an elevation of around 70 metres. Portesham lies close to several nearby settlements, including Rodden, Waddon, and West Shilvinghampton, and is characterized by its predominantly detached housing stock. Portesham is located approximately 120 miles from London and 37 miles from the nearest city, Wells. Portesham has a population of around 610 people, according to recent estimates.
Portesham and Dorset: where our fuel drain cover reaches
Portesham sits in the DT postcode area, and our vans that answer petrol in diesel call-outs there work the places near it as well — Rodden, Waddon and West Shilvinghampton among them. We drain where your car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the pump in Portesham, still?
Nothing beats it: that's where you are. Turned off it remains; then call.