Should You Worry? Petrol in a Diesel Car in Seaton
Less than you likely are, provided it has not been started. Petrol resting in a diesel tank does nothing to your motor until something pulls it through the fuel system — the ignition priming the pump, the starter, or the drive itself. So the truthful answer to the first query anyone in Seaton asks, "have I ruined it?", is usually no. Keep it that way: leave the engine off and ring Petrol in Diesel. Below, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
The engine and petrol in a diesel: what goes on
On its way through an engine, diesel does two tasks. It lubricates first, and only then does it burn. Extremely fine clearances are built into the fuel injectors and the high-pressure fuel pump, and just the diesel running through keeps those surfaces from grinding together.
The second job petrol does not do at all, and the first it does poorly. It is runnier than diesel and removes the lubrication the fuel system hinges on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
Seen together, they show what shape the problem has. Contact doesn't do the harm — movement does. Any tank with petrol in it is a fuel problem. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Four scenarios our technicians see around Seaton: how serious is petrol in a diesel?
Filled up, not once started. The best case there is. At a forecourt, and truly only there, that petrol is still limited to your tank — because anywhere else the car was driven to reach it. The job is emptying and rinsing on the spot.
A brief spell of running, or merely your ignition on. Petrol has come out of your tank and reached your filter and your lines, because the system has been primed. Normally nothing more than draining, rinsing and sorting your filter, and so still straightforward.
Your pump has worked a few miles on diluted fuel — that is what driving the car meant. Tank, lines, filter, then clean fuel run through the entire system: that is the work, and the way the car was driven matters as much as the distance. Short trips, such as the school run to Seaton Primary School, are one matter. A run as far as Exeter, under 25 miles away, is a very different job. So is any miles on the M5, under 25 miles from Seaton, where the engine has been labouring hard throughout.
Knocking, a ragged idle, smoke, a throttle gone soft: driven until it complained. The fuel is not behaving like diesel any more, and the engine is saying so. Leave it wherever it stops: a lay-by, a side street, the verge on Cross Street. Permanent damage is very uncommon when a car is pulled over quickly, and the fuel drain and flush that still come first sort it out.
Seaton drivers and the petrol in a diesel myths they hear
"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 — the tank just carries more of the same mixture. That advice supposes a diesel fuel system tolerates petrol by percentage. It does not.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." Protection counts more on modern diesels, not less, because their fuel runs through finer components at higher pressure.
Myth: "If it starts and drives, there is no harm done." This is the one that fools drivers. Feed diesel to a petrol motor and it usually will not run, so the motorist stops — and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Fine and running aren't the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different fault. What petrol has thinned remains thinned, and that petrol remains in that tank anyway.
The next start draws petrol back round your pump out of the fuel lines and the filter, where some of it sits after your engine has run. That is why draining the tank yourself does not sort it — a myth. Emptying petrol into a can at the kerbside is also truly hazardous.
Why petrol in a diesel occurs so easily
A careless moment is seldom the cause, and nobody means to do it. One way only, since of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol motor. That is how the forecourt makes it easy.
Habit and the vehicle getting out of step is when it takes place. Any car that is new to you — hired, on loan as a courtesy car, or just bought. Two motors on one drive, one petrol, one diesel. The pumps in a different order on a well-known forecourt. Rushing for a train outside Axminster and fuelling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver used to petrol: precisely when it occurs. With rain, a call arriving, or children to deal with, your hand just does what it has always done.
Seaton motorists: how to avoid petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally 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 your first fill in any vehicle 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 house has one of each. So mark it.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds daft. It works.
- Mistakes like this are simple 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 refuse a petrol nozzle, and add-on devices exist for the remainder. Count it as a safety net, then keep checking the pump.
- As soon as you realise, stop: less petrol in the tank makes a thinner blend. What to do next doesn't change, though — still do not start the car.
Seaton: already put petrol in a diesel?
Then, there is only a short order of things. Do not crank it, and do not turn the ignition on. If you're still at the forecourt — Tesco or anywhere else — ask the attendants to help you roll it clear of the petrol pump. Then ring 0333 366 0103 and tell us what was put in, about how much, and if it has run.
Corrosion and deposits form the problem with AdBlue, where petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Seaton page.
One petrol in a diesel task around Seaton costs more than another. Why?
There is no honest single quote for this, because the four situations above are four different tasks. Chiefly, the cost moves with which one you're in. Two things come after that: the petrol that was put in as a share of what that tank takes, then the spot your car is in and whether a technician can get to it safely.
What got in, how much, and if it has run — three questions our technicians ask before quoting, not after, for exactly that reason. Those answers change a range into a straight figure.
About Seaton and its setting
Seaton is a coastal town in Devon, situated on the south coast of England, approximately 20 miles from Exeter. Seaton has a population of around 7083 people and is characterised by predominantly detached housing. Seaton sits at a low elevation of 16 metres above sea level, looking out over the sea. Seaton is near to other small towns and villages, including Beer and Axmouth.
Fuel drain cover around Seaton and across Devon
Seaton sits in the EX postcode area, and our teams that answer petrol in diesel jobs there work the spots near it as well — St Dympnas, Beer and Axmouth among them. Our technicians drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Seaton and still at the petrol pump?
No position is better: that is where you are. Keep the vehicle turned off, then ring.