Should You Worry? Petrol in a Diesel Car in Bridgend
Not started? Then less anxious than you likely are. "Have I ruined it?" is the first thing anyone in Bridgend asks, and the truthful answer is usually no, because petrol left in a diesel tank hurts nothing till it is dragged through the fuel system — by ignition priming, by the starter, or by being driven. Petrol in Diesel is who to ring, with your motor left off, so it stays that way. The rest of this page covers what petrol actually 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
Two tasks fall to diesel on its route round a motor. It combusts, and before it burns it lubricates. Very fine clearances are built into the fuel injectors and the high-pressure pump, and just the diesel flowing through stops their surfaces grinding together.
Of those two jobs, petrol handles the first poorly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump on that mixture to wear itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the knocking.
Taken together, they make clear what shape the problem takes. The damage is done by movement, not by contact. A tank with petrol in it is a fuel problem. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the fuel injectors further on.
Bridgend, petrol in a diesel: four cases, from mild to significant
The best case there is: filled up, not once started. That petrol is in the tank and only the tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only really take place at a forecourt, because anywhere else the vehicle has been driven to get there.
Started for a moment, or only your ignition on. With the fuel system primed, the fuel lines and filter already contain petrol that has come from that tank. Drain, flush, deal with the fuel filter: still normally simple.
Driven a couple of miles. Now the pump has spent those miles working on diluted fuel. Tank, lines, filter, then clean fuel run through the entire system: that's this work, and the way the car was driven counts as much as the miles. Driving the children to the local primary school is one sort of trip. Very different again: a run to Cardiff, under 25 miles away, or any miles on the M4, under 3 miles from Bridgend, where your engine kept running hard.
Rattling, a ragged idle, smoke, a throttle gone soft: driven till it complained. The fuel is not acting like diesel any more, and the motor is telling you. Whether it's the verge on Market Street, a lay-by or a side road, stop where you are then leave it. A car pulled over quickly very seldom has lasting damage, because the fuel drain and the flush, which still go first, sort it out.
What Bridgend people get told about petrol in a diesel — and the stories in it
Myth: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mixture is all it gives, since topping up removes nothing. That advice presumes a diesel fuel system handles petrol by percentage. It does not.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. Finer parts and higher pressure are the way a modern diesel runs its fuel, and that makes the lubrication matter more, not less.
"It starts, it drives, so no harm done" — the myth that catches more drivers than any other. A petrol motor fed diesel usually won't run, so the driver stops and the harm stops with them. Feed petrol to a diesel and it generally starts, ticks over and drives away as if nothing happened — all while its pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive the car home." It's an old workaround for a different fault. It doesn't put back what petrol has weakened, and that petrol is still in that tank after that.
If the motor has run, part of the petrol is in the fuel filter and the fuel lines, not the tank — and the next start pulls it right back through the pump. So the myth "drain the tank yourself and you are sorted" does not hold. Clearing petrol into a can by the roadside is also genuinely hazardous.
Why petrol in a diesel happens at all
No one does it on purpose, and it's seldom carelessness. A diesel nozzle mostly won't fit a petrol vehicle, but the smaller petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake easy, and just in one direction.
Habit and your car getting out of step is how it happens. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps arranged differently. A rushed fill en route to the nearest station with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver used to petrol: precisely when it occurs. Add a back seat full of kids, a phone call or rain, and habit takes over.
Bridgend people: how to avoid petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is only a clue.
- The first fill in a strange motor is the time to check your filler flap — on it, or on the cap, plenty of vehicles state which fuel to use.
- Label your key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- It sounds daft and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and aftermarket devices exist for the rest. Count it as a backstop, and keep reading the pump.
- Less petrol means a weaker mix, and so stop as soon as you realise — while remembering that your next stage is unchanged. It's still not to start the car.
Already put petrol in a diesel in Bridgend?
The order of things is brief, then. Do not turn the ignition on, and don't fire it up. If you're still on the forecourt — Tesco or anywhere else — ask the attendants to help you push the vehicle clear of the pump. What went in, about how much, and whether it's run: tell us that when you phone 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different fault — Bridgend has a page just for it.
What makes one Bridgend petrol in a diesel task cost more than the next
There's no fair single quote for this, since the four situations above are four different jobs. What moves the cost is chiefly which of them you're in. Where the vehicle is matters too, and whether a technician can safely reach it, after the proportion of petrol to what that tank holds.
Before any quote, not after, come three queries: your fuel that got in, the amount, and if it has run. That's why. A range becomes a straight figure when those replies are in.
About Bridgend, for a moment
Bridgend is a town situated on the riverside in south Wales, with an elevation of around 21 metres above sea level. Bridgend lies near the Ogmore River and is close to several nearby places, including Newcastle, Tremains, and Ystrad Fawr. Bridgend has a population of approximately 22,673 people and predominantly consists of semi-detached housing. Bridgend is located about 17 miles from Cardiff and 148 miles from London.
Fuel drain cover across Bridgend, Bridgend included
Newcastle, Tremains and Ystrad Fawr are among the places around Bridgend that the same vans work, answering petrol in diesel calls across Bridgend's CF postcode area. The car doesn't need to move to us: our engineers drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the petrol pump around Bridgend, still?
Then, you couldn't be in a better place. Phone, and keep it turned off.