Should You Worry? Petrol in a Diesel Car in Winterfield
If it has not been started, you can worry less than you probably are. Until your ignition primes the pump, your starter turns, or your vehicle is driven, petrol in a diesel tank just rests there and does nothing. Which makes the honest reply to that first Winterfield query — "have I ruined it?" — usually no. Keep it like that: leave the motor off and ring Petrol in Diesel. Below, this page sets out what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
Inside your engine: what petrol in a diesel really does
On its way through an engine, diesel has two jobs. It combusts, and before it burns it lubricates. Very fine gaps are built into the fuel injectors and the high-pressure pump, and just the diesel running through stops those surfaces grinding together.
The second task petrol doesn't do at all, and the first it does poorly. A pump running on a petrol blend is wearing itself out, because petrol is thinner than diesel and takes away the lubrication your fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the rattling starts.
The shape of the problem is clear when you put those together. Not contact but circulation is what causes the damage. Any tank with petrol in it is a fuel issue. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to the fuel injectors beyond it.
Four scenarios our technicians see around Winterfield: how serious is petrol in a diesel?
Fuelled but never started — as good as it gets. The petrol is in the tank and just your tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only really occur at a forecourt, because anywhere else your car has been driven to get there.
Started for a moment, or only your ignition on. The fuel system has been bled, and so petrol has left that tank and reached your filter and the fuel lines. Normally nothing more than clearing, cleaning and seeing to the fuel filter, and so still simple.
A couple of miles driven, and the pump has spent every one of them labouring on diluted fuel. Tank, lines, filter, then fresh fuel put through the entire system: that is this work, and the way your car was driven counts as much as the distance. Driving the children to Paulton Infant School is one sort of trip. Driving as far as Bath, under 10 miles away, makes a very different task — as does any mileage on the M32, under 15 miles from Winterfield, with your engine labouring hard the whole time.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone lumpy. The motor is telling you your fuel is no longer behaving like diesel. Whether it is the verge on Phillis Hill, a lay-by or a side road, stop where you are and leave it. What goes first is still the fuel drain and flush, and that takes care of it, with permanent damage very rare if a car is stopped soon.
Winterfield people and the petrol in a diesel myths they hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Topping up takes out nothing; it gives you a fuller tank of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that advice presumes.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise components: that is how a newer diesel handles its fuel, so the protection counts for more, not less.
Myth: "If it starts and drives, there's no harm done." This is the one that fools drivers. The motorist of a petrol engine fed diesel usually stops, since it will not run, and the damage stops there. While your pump grinds, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an outdated fix for a distinct issue. What petrol has thinned stays thinned, and that petrol stays in that tank anyway.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol sits in your filter and lines, ready to go right back through your pump at your next start. It's also truly hazardous to drain petrol into a can at the roadside.
Petrol in a diesel: how does it happen?
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol motor at all. So the mistake runs one way.
The moment habit stops matching the car is the moment it occurs. A motor that's new to you — a hire car, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. A hurried fill en route to Oldfield Park with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it happens. Add a back seat full of kids, a phone call or rain, and habit wins.
Winterfield motorists: how to prevent petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most usually do. Check the pump's label; the colour is only a hint.
- The first fill in an unfamiliar motor is the time to check your filler flap — inside it, or on the cap, many vehicles state the fuel they take.
- Good intentions count for less than a sticker or a fob in a vivid colour on your diesel's key if a house has one of each. So mark it.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Silly, yes, yet it does the trick.
- Tuck the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to block a petrol nozzle, and add-on devices exist for the remainder. Count it as a backstop, and keep reading the petrol pump.
- Less petrol means a weaker mix, so stop as soon as you notice — while remembering that your next stage is unchanged. It's still not to start it.
Petrol already in a diesel around Winterfield? Begin here
Then, there is just a short order of things. Leave it unstarted, with the ignition switched off as well. Ask the attendants to help you push it clear of the petrol pump if you are still on the forecourt, whether that's Tesco or somewhere else. Then phone 0333 366 0103 and tell us what got in, about how much, and if it has run.
If it was AdBlue rather than petrol, say so. That's a different problem — corrosion and deposits instead of lost protection — and it has its own page for Winterfield.
Why one petrol in a diesel job around Winterfield costs more than another
There is no honest single quote for this, since the four scenarios above are four separate tasks. Which of them you are in is chiefly what moves your cost. Where the vehicle is matters too, and whether a van can safely reach it, after the ratio of petrol to what the tank holds.
That's why our technicians ask three questions before pricing instead of after: what went in, how much, and if it has run. Their replies are what change a range into one firm number.
About Winterfield, for a moment
Winterfield is a locality in Somerset, situated on the riverside in the South West of England, with an elevation of around 138 metres. Winterfield lies approximately 8 miles from the city of Bath and is surrounded by nearby places such as Monger, Thicket Mead, and Greenhill. Winterfield has a population of around 1290 residents, predominantly living in semi-detached housing. Winterfield is also relatively distant from London, at a distance of around 103 miles.
Fuel drain cover across Somerset, Winterfield included
The vans answering petrol in diesel calls around Winterfield, in the BS postcode area, equally work the places near it, Monger, Thicket Mead and Greenhill included. Our technicians drain where the vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Winterfield and still at the petrol pump?
The best position there is, then — that's where you are. Turned off it stays; then call.