Adeney: Petrol in a Diesel Car? How Worried to Be
Not started? Then less anxious than you likely are. Petrol sitting in a diesel tank does nothing to the motor till something pulls it through the system — the ignition priming your pump, your starter, or driving itself. So the truthful answer to the first question anyone in Adeney asks, "have I wrecked it?", is normally no. To keep the car that way, phone Petrol in Diesel then leave the motor switched off. What petrol actually does to a diesel, how to judge how far it's travelled, and how to keep it from happening again: that's the remainder of this page.
Petrol in a diesel: what does it do to the engine?
On its way through an engine, diesel has two jobs. Lubricating comes before burning; it does both. Built to extremely fine clearances, the fuel injectors and the pump depend on the diesel flowing through them to keep their surfaces from wearing against one another.
Petrol handles the first job poorly and the second not at all. A pump working on a petrol mix is wearing itself out, since petrol is thinner than diesel and strips out the protection your fuel system depends on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any knocking starts.
Together, those leave the shape of the problem plain. The harm is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel problem. The beginning of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with your fuel to your injectors downstream.
Four scenarios our engineers see in Adeney: how bad is petrol in a diesel?
Filled up, and never started: nothing beats it. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held in that tank alone, it's cleared and purged on the spot, and nothing more is needed.
Ignition on, or started for a moment. Your system has been primed, so petrol has left your tank and got to the fuel filter and your lines. Normally nothing more than emptying, purging and seeing to the fuel filter, and so still straightforward.
Some miles driven, and your pump has spent each of them labouring on diluted fuel. Tank, lines, filter, then clean fuel run through the whole system: that's this work, and the way the vehicle was driven matters as much as the distance. The school run to St Peter's Church of England Controlled Primary School and Nursery is one thing. Any miles on the M54, under 10 miles from Adeney, means the engine has worked hard throughout, and a run to Wolverhampton, under 25 miles away, makes a very different task as well.
Clattering, an uneven idle, smoke, a throttle gone soft: driven until it complained. The engine is telling you the fuel is no longer behaving like diesel. Pull up on the spot — on the verge on Adeney Road, at the kerb, down a side road — and don't move it. Permanent damage is very rare when a vehicle is stopped quickly, and the fuel drain and flush that still go first deal with it.
Petrol in a diesel myths Adeney motorists hear
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Topping up takes out nothing; it gives you a fuller tank of the same mix. That guidance presumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Lubrication matters more on modern diesels, not less, since their fuel runs through smaller components at higher pressure.
"It starts, it drives, so no harm done" — the myth that trips up most drivers than any other. A petrol engine fed diesel generally will not run, and so the motorist stops and the harm stops with them. Feed petrol to a diesel and it normally fires up, idles and drives away as if nothing has happened — all the while its pump wears. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct problem. The petrol is still inside the tank afterwards, and whatever it has thinned is not put back.
"Drain it yourself and you are sorted" — a myth, since after it's been running some petrol sits in your filter and lines, waiting to go right back through the pump on the next start. It is also really hazardous to drain petrol into a can by the roadside.
Petrol in a diesel: how does it occur?
It's rarely carelessness, and no one does it on purpose. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it easy, and the slip runs one way.
It takes place when habit and your car stop matching. A new car, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. A familiar forecourt with the pumps in a different order. Rushing for a train at Oakengates and filling up en route. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: exactly when it takes place. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
How to avoid petrol in a diesel at your next fill-up in Adeney
- The label is what matters, and so check the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, but not on each forecourt.
- Check your filler flap. Many vehicles state the fuel inside the flap or on the cap. Look at it on your first fill in a vehicle you don't know.
- One of each in the house? Mark your key to the diesel — a coloured fob, a sticker — since intending to remember isn't enough.
- Before the nozzle comes off the pump the first time you fuel a hired or new vehicle, say "diesel" out loud. Daft, perhaps, yet it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the petrol pump.
- Spotting it halfway? Stop there and then. A weaker mix results from less petrol inside your tank, but your next stage remains the same: don't fire it up.
Already put petrol in a diesel in Adeney?
In that case, there's just a short order of things. Starting it is out, and so is turning on the ignition. Ask the staff to help you push it away from the pump if you are still at the forecourt, whether that's Shell or anywhere else. Then phone 0333 366 0103 and tell us what went in, about how much, and whether it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different problem — Adeney has a page just for it.
One petrol in a diesel job in Adeney costs more than another. Why?
The four scenarios above are four separate tasks, so no single price for this would be honest. Mostly, your cost shifts with which one you are in. Two things follow that: the petrol that was put in as a share of what the tank holds, then the spot your car is in and whether a van can get to it safely.
That's why our engineers ask three queries before quoting instead of after: what went in, how much, and if it has run. The replies change a range into a straight figure.
About Adeney and its setting
Adeney is a small hamlet situated on the riverside in Shropshire, with a low elevation of around 65 metres. Adeney lies near several other small settlements, including Cheswell, Tibberton, and Edgmond, and is located approximately 18 miles from Wolverhampton. Adeney has a population of around 806 people, predominantly living in detached houses. Adeney is also relatively distant from London, at around 131 miles away.
Adeney and Shropshire: where our fuel drain cover reaches
Petrol in diesel jobs in Adeney — part of the TF postcode area — go to vans that also cover the locations about it, Cheswell, Tibberton and Edgmond included. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and your car doesn't need to come to us.
Adeney: still at the petrol pump?
Then you are in the best spot there is. Switched off it remains; then call.