Petrol in a Diesel Car in Woodmancote: How Worried Should You Be?
Provided it has not been started, worry less than you probably are. "Have I wrecked it?" is the first question everyone around Woodmancote asks, and the honest answer is normally no, since petrol resting in a diesel tank harms nothing till it is dragged through your fuel system — by ignition priming, by the starter, or by driving. To keep it like that, phone Petrol in Diesel then leave the motor switched off. The remainder of this page explains what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
What petrol in a diesel does to the engine
Passing through an engine, diesel is doing two jobs at once. Lubricating comes before burning; it does both. Your high-pressure pump and your injectors are built to extremely fine gaps, and the diesel passing through them is what stops those surfaces from grinding against one another.
Poorly at the first, not at all at the second: that's petrol. A pump working on a petrol blend is wearing itself out, since petrol is thinner than diesel and strips out the lubrication your fuel system depends 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 knocking comes.
Combined, those make the shape of the issue clear. The damage is done by circulation, not by contact. Petrol in the tank is a fuel fault. After the pump has been labouring on that petrol, a mechanical fault has begun: anything shed by a pump that is wearing down is carried downstream to the fuel injectors with the fuel.
How bad is petrol in a diesel? Four situations our engineers see around Woodmancote
Filled but never started — the best it gets. On a forecourt, and genuinely only there, that petrol is still limited to that tank — since anywhere else the car was driven to get to it. The task is emptying and purging on the spot.
Ignition on, or started for a second. Petrol has come out of the tank and got to your filter and the lines, because your system has been bled. That's normally still a simple task — a drain, a flush, and your filter seen to.
Driven a few miles. Now your pump has spent these miles labouring on weakened fuel. Distance is only half of that; how hard it was driven counts equally. Either way the work includes the tank, the fuel lines, the filter and fresh fuel through the entire system. Driving the kids to Dursley Church of England Primary Academy is one sort of trip. Getting as far as Gloucester, under 15 miles away, makes a very different task — as does any mileage on the M5, under 3 miles from Woodmancote, with your engine labouring hard all the way.
Knocking, a ragged idle, smoke, a throttle gone soft: driven until it complained. The engine is telling you your fuel is no longer acting like diesel. Stop where you are — on the verge on Uley Road, at the kerb, down a side road — and do not move it again. A car stopped soon very rarely has long-term damage, because the fuel drain and the flush, which still go first, sort it out.
What Woodmancote drivers get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. A fuller tank of the same mix is all you get, because topping up takes out nothing. A diesel fuel system does not tolerate petrol by percentage in the way that guidance supposes.
Myth: a current diesel copes with a bit of petrol. If anything, the reverse. Protection matters more on modern diesels, not less, because their fuel passes through more precise components at higher pressure.
The myth that catches drivers out: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it generally will not run, and so the driver stops — and the damage stops with them. Feed petrol to a diesel and it generally starts, idles and pulls away as if nothing has happened — all while its pump wears. Running is not 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 problem. None of what petrol diluted gets put back by it — and afterwards, that tank still holds the petrol.
The next start draws petrol back round your pump out of the fuel lines and the fuel filter, where some of that ends up after the motor has been run. That is why a DIY tank drain doesn't sort it — a myth. Also, a can of petrol filled by the roadside is genuinely risky.
Petrol in a diesel: how does it take place?
On purpose? Never. Through carelessness? Seldom, if ever. A diesel nozzle generally won't fit a petrol vehicle, yet the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake easy, and just in that direction.
It takes place when routine and the car stop matching. Courtesy car, hire car, or a car that's new. A household with one petrol and one diesel on the drive. The pumps in a different order on a familiar forecourt. Racing for a train outside Cam & Dursley and filling up en route. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it happens. With rain, a call coming in, or children to deal with, your hand just does what it always has.
How to prevent petrol in a diesel on your next fill-up in Woodmancote
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Trust the label on the petrol pump, not the colour.
- Plenty of cars state the fuel inside your filler flap or on the cap, so check there on your first fill in any vehicle you don't know.
- One of each in the home? Label your key to the diesel — a bright fob, a sticker — since intending to remember isn't enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It sounds daft and it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the pump.
- Add-on devices exist for motors without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside the tank means a thinner mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Woodmancote?
In that case, there's only a short order of things. Starting it is out, and so is switching on your ignition. Ask the attendants to help you push it away from the pump if you are still on the forecourt, whether that is Texaco or anywhere else. Next, 0333 366 0103. We'll ask what went in, roughly how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That is a different fault — corrosion and deposits rather than lost protection — and it has its own page for Woodmancote.
One petrol in a diesel task in Woodmancote costs more than another. Why?
There is no fair single price for this, since the four situations above are four different tasks. What moves your cost is chiefly which of them you're in. Two things come after that: the petrol that was put in as a proportion of what your tank holds, then the place your car is in and whether a van can get to it safely.
That is why our engineers ask three questions before costing rather than after: what was put in, how much, and whether it has run. Given the answers, you get a straight figure instead of a range.
About Woodmancote itself
Woodmancote is a suburban area in Gloucestershire, situated near the River Severn at an elevation of 79 metres. Woodmancote lies within commuting distance of Gloucester, approximately 13.5 miles away, and is also within reach of nearby towns such as Dursley. Woodmancote has a population of around 4440 people, predominantly living in semi-detached housing. Woodmancote is located in the South West region, about 96 miles west of London.
Fuel drain cover across Gloucestershire, Woodmancote included
Highfields, Dursley and Townsend are among the locations around Woodmancote that the same vans work, answering petrol in diesel jobs across Woodmancote's GL postcode area. 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.
Woodmancote: still at the pump?
Then you are in the best spot there can be. Keep the car switched off, then ring.