Should You Worry? Petrol in a Diesel Car in Tynewydd
Likely less than you are now — provided nobody has started the car. Petrol resting in a diesel tank does nothing to the engine until something draws it through the fuel system — the ignition priming the pump, the starter, or the drive on its own. So the honest answer to the first question anyone around Tynewydd asks, "have I ruined it?", is usually no. Petrol in Diesel is who to call, with your motor kept off, and so it stays that way. Keep reading for three things: the effect petrol has inside a diesel motor, the signs of how far it has got, and ways to make sure you don't do it again.
Petrol in a diesel: what does it do to the engine?
Passing through an engine, diesel is doing two jobs at the same time. It ignites, and before it ignites it protects. Built to very fine clearances, the injectors and the pump rely on your diesel moving through them to keep their surfaces from wearing against one another.
The second job petrol doesn't do at all, and the first it does poorly. A pump working on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the protection the fuel system relies on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel needs from its fuel — and that's where the rattling comes.
Combined, those make the shape of the problem clear. Not contact but circulation is what causes the harm. Petrol in a tank is a fuel problem. After your pump has been working on that petrol, a mechanical problem has begun: whatever is shed by a pump that is wearing down is carried downstream to the injectors with the fuel.
Four scenarios we see in Tynewydd: how serious is petrol in a diesel?
Filled up, and not started: nothing beats it. On a forecourt, and really only there, that petrol is still confined to your tank — since everywhere else the vehicle was driven to get to it. The task is draining and cleaning on the spot.
Ignition on, or started for a second. The fuel system has been bled, and so petrol has left that tank and got to the filter and the lines. Usually nothing more than draining, cleaning and seeing to the fuel filter, and so still straightforward.
Your pump now spent a couple of miles on diluted fuel — that is what driving the car does. Tank, lines, filter, then fresh fuel put through the entire circuit: that is the work, and the way the car was driven matters as much as the miles. A school run to the local primary school is one thing. Driving as far as Newport, under 25 miles away, makes a very different task — as does any miles on the M4, under 25 miles from Tynewydd, with the engine working hard all the way.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. That's the motor telling you its fuel has stopped acting like diesel. Whether it is the verge on Tynewydd, a lay-by or a side street, stop there and leave it. A car stopped quickly very seldom has long-term damage, since the drain and the flush-through, which still go first, sort it out.
Myths Tynewydd drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a fuller tank of the same mix. The idea behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A current diesel can cope with a bit of petrol." Finer parts and higher pressure are how a modern diesel runs its fuel, and that makes the protection count more, not less.
One myth that catches drivers out: if it starts and drives, it must be unharmed. The motorist of a petrol motor fed diesel usually stops, because it will not run, and the harm stops with them. Feed petrol to a diesel and it normally fires up, ticks over and pulls away as if nothing happened — all the while its pump wears. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an old fix for a distinct issue. It does not put back what petrol has diluted, and the petrol is still in your tank later.
Myth: "Drain that tank yourself and you're sorted." Once your engine has run, some of that petrol is no longer in that tank: it's in your filter and your lines, and it goes straight back through your pump at the next start. Emptying petrol into a can at the roadside is also truly hazardous.
How petrol ends up: petrol in a diesel
A careless moment is seldom the cause, and nobody means to do it. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol vehicle. That's how the forecourt makes it easy.
The moment habit stops matching the car is the moment it happens. Any vehicle that is new to you — hired, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the drive. Your usual forecourt, its pumps now in a different order. A hurried fill en route to Rhymney with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Golf in front of you on the forecourt for its first tank — that's when. With rain, a call coming in, or a car full of children to deal with, your hand simply does what it always has.
Next time you fill up in Tynewydd: preventing petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what counts.
- The first fill in a strange vehicle is the time to check the filler flap — inside it, or on the cap, plenty of motors state the fuel they take.
- One of each in the home? Label your key to the diesel — a bright fob, a sticker — since intending to remember isn't enough.
- It seems daft and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- Put the phone away. This is an easy mistake to make whilst you're thinking about something else.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices exist for motors without one. They are a safety net, not a reason to stop checking the pump.
- Spotting it mid-fill? Stop at once. A weaker blend results from less petrol in the tank, but your next stage remains the same: do not fire it up.
Already put petrol in a diesel around Tynewydd?
The order of things is short, then. Do not switch your ignition on, and don't fire it up. The staff on the forecourt — whether at Texaco itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Then ring 0333 366 0103 and tell us what went in, about how much, and whether it's run.
If it was AdBlue instead of petrol, say so. That's a different fault — corrosion and deposits rather than lost protection — and it has its own page for Tynewydd.
Tynewydd petrol in a diesel jobs: why one costs more than another
Four separate jobs sit behind the four scenarios above — which is why there is no honest single price. Which of them you're in is mostly what moves the cost. The proportion matters next, meaning how much of the tank is petrol, and then the location of the vehicle and whether reaching it is safe for a technician.
That's why our technicians ask three questions before quoting rather than after: what was put in, how much, and whether it has run. A range turns into a straight figure when those answers are in.
About Tynewydd, for a moment
Tynewydd is a suburban area situated in the county of Blaenau Gwent in Wales, with a riverside setting and an elevation of 371 metres. Tynewydd is located near the communities of Waundeg, Nant-y-Bwch, and Blaen-y-cwm, and is approximately 18 miles from the city of Newport. Tynewydd has a population of around 933 people and is characterised by semi-detached housing. Tynewydd is also relatively distant from London, at a distance of around 136 miles.
Across Blaenau Gwent and around Tynewydd: fuel drain cover
Petrol in diesel call-outs in Tynewydd — part of the NP postcode area — go to vans that likewise cover the spots about it, Waundeg, Nant-y-Bwch and Blaen-y-cwm among them. No need to move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all spots we drain.
In Tynewydd and still at the pump?
The best place there is, then — that is where you are. Keep the vehicle turned off, and ring.