Wisbech St Mary: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less worried than you probably are. Petrol sitting in a diesel tank does nothing to your engine till something draws it through the system — your ignition priming your pump, the starter, or driving itself. So the fair answer to the first question anyone around Wisbech St Mary asks, "have I ruined it?", is normally no. To keep it that way, ring Petrol in Diesel and leave your engine switched off. The rest of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
The engine and petrol in a diesel: what happens
Diesel does two jobs on its way through an engine. Lubricating comes before burning; it does both. Very fine clearances are built into the fuel injectors and the high-pressure pump, and only the diesel flowing through stops their surfaces grinding together.
Of these two tasks, petrol handles the first badly and the second never. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on the blend wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the rattling.
The shape of the trouble is plain once you put those together. Contact doesn't do the harm — movement does. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds goes on, carried by your fuel, into your injectors downstream, which is why a pump that has been working on the petrol is where a mechanical problem starts.
Wisbech St Mary, petrol in a diesel: four cases, from mild to major
Filled but not once started — as good as it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With that petrol held in that tank alone, it's cleared and purged right where it stands, and nothing more is needed.
Ignition on, or started for a moment. Once primed, your system has drawn petrol out of your tank as far as the filter and your lines. Drain, flush, see to the fuel filter: still normally straightforward.
The pump now spent a few miles on weakened fuel — that's what driving it does. Miles is only half of it; how hard it was driven matters equally. Either way this work runs to the tank, the fuel lines, the fuel filter and fresh fuel through the entire circuit. A school run to Wisbech St Mary CofE Academy is one thing. Any mileage on the A1(M), under 25 miles from Wisbech St Mary, means the motor working hard throughout, and a run to Peterborough, under 25 miles away, is a very different job too.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. What you are hearing is your motor reporting fuel that no longer runs like diesel. Whether it's the verge on Chapel Avenue, a lay-by or a side road, stop there then leave it. The fuel drain and flush still go first, and they deal with it: if a vehicle is pulled over quickly, lasting damage is very unusual.
What Wisbech St Mary people get told about petrol in a diesel — and the stories in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing comes out when you top up — your tank simply carries more of the same mixture. A diesel fuel system doesn't accept petrol by percentage in the way that advice assumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through smaller parts: that is how a current diesel handles its fuel, so the lubrication matters for more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that catches drivers. The driver of a petrol engine fed diesel usually stops, because it will not run, and the harm stops there. Feed petrol to a diesel and it generally starts, ticks over and pulls away as if nothing has happened — all while its pump wears. 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. The petrol is still inside your tank after that, and whatever it has weakened isn't put back.
The next start sends petrol back round the pump from your lines and the fuel filter, where some of it sits once the engine has been run. That is why draining the tank yourself does not sort it — a myth. Besides, petrol emptied into a can by the road is truly dangerous.
Petrol in a diesel: how does it occur?
Carelessness is seldom the cause, and nobody means to do it. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol motor at all. The forecourt makes it simple, and the mistake runs one way.
The moment habit stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a vehicle that's brand new. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. Filling up in a rush on the way to March, with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that is when. With rain, a call arriving, or children to deal with, the hand just does what it has always done.
Next time you fill up around Wisbech St Mary: 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.
- The first fill in an unfamiliar car is the time to check your filler flap — inside it, or on the cap, many motors state which fuel to use.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, for a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It sounds daft and it does the trick.
- Put the phone away. This is an easy mistake to make whilst you are thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to block a petrol nozzle, and add-on devices exist for motors without one. They are a safety net, not a reason to stop checking the petrol pump.
- Spotting it halfway? Stop there and then. A weaker mix follows from less petrol inside your tank, but the next step remains the same: don't start the vehicle.
Petrol already in a diesel around Wisbech St Mary? Start here
Then the order of things is short. Do not fire it up, and do not turn your ignition on. The staff on the forecourt — whether at Pace itself or wherever you filled up — will normally help roll it clear of the pump if you ask. Then phone 0333 366 0103 and tell us what was put in, roughly how much, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Wisbech St Mary has a page all for it.
What makes one Wisbech St Mary petrol in a diesel task cost more than the next
There is no honest single quote for this, since the four situations above are four different tasks. Mostly, the cost shifts with which situation you are in. Next it is the proportion — how much petrol was put in against how much that tank holds — and after that where the vehicle is and whether our van can reach it safely.
Three questions come first, before quoting, rather than after — what went in, how much, has it run — and that is the reason. A range becomes a straight figure when those replies are in.
About Wisbech St Mary itself
Wisbech St Mary is a village in Cambridgeshire, situated in a low-lying area of the Fens, with an elevation of around 4 metres. Wisbech St Mary lies near several other small settlements, including Bunkers Hill and Leverington Common, and is characterized by its predominantly detached housing stock. Wisbech St Mary is located approximately 15 miles from Peterborough and 80 miles from London, making it a rural community with some commuter links.
Across Cambridgeshire and around Wisbech St Mary: fuel drain cover
Bunkers Hill, Tholomas Drove and Leverington Common are among the places around Wisbech St Mary that the same teams work, answering petrol in diesel calls across Wisbech St Mary's PE postcode area. The vehicle doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Wisbech St Mary: still at the pump?
In that case, you could not be in a better position. Switched off it stays; then phone.