Should You Worry? Petrol in a Diesel Car in Cwmfelin
Not started? Then less anxious than you probably are. "Have I wrecked it?" is the first thing anyone in Cwmfelin asks, and the truthful answer is usually no, since petrol left in a diesel tank hurts nothing till it is drawn through your fuel system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to call, with your motor kept off, so it stays that way. The rest of this page covers 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 again.
Inside the engine: what petrol in a diesel really does
Passing through a motor, diesel does two things at once. It ignites, and before it ignites it protects. Extremely fine tolerances go into the injectors and your high-pressure pump, and just the diesel flowing through keeps their surfaces from grinding together.
Poorly at the first, not at all at the second: that is petrol. It's runnier than diesel and takes away the lubrication the fuel system hinges on, and so a pump running on a petrol mixture is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the rattling comes from.
Combined, those leave the shape of the trouble clear. It is circulation that causes the damage, not contact. Where the petrol is only inside your tank, it's an issue of fuel, nothing more. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the injectors further on.
Cwmfelin, petrol in a diesel: four situations, from mild to major
Fuelled but never started — the best it gets. The petrol is in your tank and only your tank, and the job is a drain and a flush where the vehicle stands. This is the one scenario that can only truly take place at a forecourt, since anywhere else your car has been driven to get there.
Your ignition switched on, or a short start. The system has been primed, so petrol has left the tank and reached the fuel filter and the lines. That is normally still an easy task — a drain, a flush, and the fuel filter dealt with.
A couple of miles driven, and your pump has spent each of them labouring on weakened fuel. How hard the car was driven counts as much as how far, and the work takes in that tank, the lines, your filter and fresh fuel through the whole system. Driving the children to the local primary school is one sort of trip. A run as far as Swansea, under 15 miles away, is a very different job. So is any mileage on the M4, under 5 miles from Cwmfelin, where the engine has been running hard throughout.
It complained, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. What you are hearing is the engine signalling fuel that no longer behaves like diesel. Stop wherever you are — the verge on Heol Cerdin, a lay-by, a side street — then leave the vehicle there. A car pulled over quickly very seldom has permanent damage, because the fuel drain and the flush, which still come first, sort it out.
What Cwmfelin people 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. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. More precise components and higher pressure are how a current diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that catches motorists. Myth: "If it starts and drives, there's no harm done." Diesel in a petrol motor normally means a motor that won't run: the driver stops, and so does the harm. A diesel fed petrol generally starts, ticks over and drives away as if nothing has happened, while the pump grinds. Running is not the same as fine.
An old fix for a separate problem is behind this one. Myth: "Add some two-stroke oil and drive the car home." It does not put back what petrol has thinned, and the petrol is still in that tank later.
Myth: "Drain that tank yourself and you are sorted." After the motor has been run, some of the petrol is no longer inside that tank: it is in your filter and the lines, and it goes straight back through your pump at your next start. It is also truly dangerous to drain petrol into a can at the roadside.
Petrol in a diesel: how does it take place?
No one does it on purpose, and it is rarely carelessness. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol vehicle at all. So the error runs one way.
The moment habit stops matching the car is the moment it occurs. Courtesy car, hire car, or a car that's brand new. Two motors on one driveway, one petrol, one diesel. A forecourt you know, but with its pumps laid out differently. A train to catch, and a rushed fill en route to Garth (Mid Glamorgan). The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it takes place. Throw in rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Next time you fill up in Cwmfelin: avoiding petrol in a diesel
- The label is what counts, so check the pump instead of the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Plenty of vehicles state the fuel inside your filler flap or on the cap, and so check it on your first fill in a motor you don't know.
- One of each in the house? Label your key to the diesel — a bright fob, a sticker — since intending to remember isn't enough.
- Before the nozzle comes off the petrol pump the first time you fill a hired or new car, say "diesel" aloud. Daft, yes, yet it works.
- Whilst you're thinking about something else, this is an easy mistake to make — so put the phone away.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to refuse a petrol nozzle, and add-on devices exist for vehicles without one. They are a safety net, not a reason to stop checking the petrol pump.
- Spotting it halfway? Stop at once. A thinner mixture results from less petrol in the tank, but your next step remains the same: don't start the vehicle.
Petrol already in a diesel in Cwmfelin? Begin here
Then the order of things is short. Leave it unstarted, with the ignition switched off too. Ask the staff to help you roll it clear of the petrol pump if you are still at the forecourt, whether that's the nearest petrol station or somewhere else. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it has been run.
Corrosion and deposits form the issue with AdBlue, where petrol brings lost protection. So if it was AdBlue, say so — and read its own Cwmfelin page.
Cwmfelin petrol in a diesel jobs: why one costs more than another
There's no fair single price for this, because the four scenarios above are four separate tasks. What shifts the 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 that tank takes, then the place the vehicle is in and whether a technician can reach it safely.
Three queries come first, before quoting, rather than after — what went in, how much, has it run — and this is the reason. Their replies are what turn a range into one firm number.
About Cwmfelin and where it is
Cwmfelin is a suburban area in Bridgend, situated on the riverside at an elevation of 98 metres. Cwmfelin lies near the communities of Garth, Pont Rhyd-y-cyff, and Llangynwyd, and is approximately 13 miles from Swansea. Cwmfelin has a population of around 2738 people, predominantly living in detached housing. Cwmfelin is also within commuting distance of major cities, being around 151 miles from London.
Fuel drain cover across Bridgend, Cwmfelin included
Garth, Pont Rhyd-y-cyff and Llangynwyd are among the locations around Cwmfelin that the same vans work, answering petrol in diesel calls across Cwmfelin's CF postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all places we drain, and the vehicle doesn't need to move to us.
In Cwmfelin and still at the pump?
No position is better: that's where you now are. Keep it off. Ring.