Glyncoed: Petrol in a Diesel Car? How Worried to Be
Likely less than you are now — as long as no one has started it. Everyone in Glyncoed starts with "have I wrecked it?", and the fair answer is normally no: petrol left inside the tank of any diesel stays harmless until priming, cranking or driving draws it into the system. To keep the vehicle that way, phone Petrol in Diesel and leave the motor alone. The remainder of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
What petrol in a diesel does to the motor
Two tasks fall to diesel on its route round a motor. Before it burns, it protects — and then it burns. Your high-pressure pump and the injectors are designed to very fine clearances, and your diesel passing through them is what keeps those surfaces from grinding against each other.
Of these two jobs, petrol manages the first badly and the second never. It's thinner than diesel and strips away the protection your fuel system rests on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the clattering comes from.
The shape of the problem is plain once you put those together. It's movement that does the damage, not contact. Where the petrol is only in your tank, it's a fault of fuel, nothing more. After your pump has been labouring on that petrol, a mechanical fault has started: anything shed by a pump that's wearing down travels downstream to the fuel injectors with your fuel.
Petrol in a diesel in Glyncoed: how serious is it? Four cases
Fuelled up, never started. The best case there can be. The petrol is inside the tank and only the tank, and the task is a drain and a flush where the vehicle stands. This is the one situation that can only truly happen at a forecourt, as anywhere else the vehicle has been driven to get there.
The ignition turned on, or a brief start. The fuel system has been bled, so petrol has left that tank and reached the fuel filter and your lines. Normally nothing more than draining, purging and sorting the fuel filter, so still easy.
Those few miles on the road were your pump labouring on fuel thinned by petrol the whole way. Tank, lines, filter, then clean fuel put through the entire system: that is the work, and the way your car was driven counts as much as the miles. On the school run to the local primary school, the distance is small. Driving as far as Newport, under 25 miles away, makes a very different job — as does any distance on the M4, under 25 miles from Glyncoed, with the engine labouring hard all the way.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Pull up on the spot — on the verge on Panteg, at the kerb, down a side road — and do not move it. A vehicle stopped early very rarely has lasting damage, because the fuel drain and the flush, which still go first, deal with it.
Myths Glyncoed drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — the tank simply holds more of the same blend. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance assumes.
"Modern diesels can handle a little petrol" — a myth, and closer to the opposite. More precise parts and higher pressure are how a modern diesel runs its fuel, and that makes the lubrication matter more, not less.
The myth that catches people off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it normally will not run, and so the motorist stops — and the damage stops with them. Feed petrol to a diesel and it usually starts, ticks over and pulls away like nothing happened — all the while its pump is wearing. A running engine does not mean fine.
Myth: "Add some two-stroke oil and drive it home." It is an old workaround for a different problem. That petrol is still in the tank after that, and what it has weakened is not put back.
Myth: "Drain that tank yourself and you're sorted." After the engine has been run, some of that petrol is no longer inside the tank: it is in your filter and your lines, and it goes straight back through your pump at your next start. Also, a can of petrol filled at the kerbside is truly dangerous.
Petrol in a diesel: how does it happen?
Carelessness is rarely the cause, and no one means to do it. One way only, since of the nozzles: the slimmer petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one generally will not fit a petrol car. That is how the forecourt makes it easy.
It happens when habit and your car stop matching. A new motor, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. Your ordinary forecourt, its pumps suddenly in a different order. A hurried fill en route to Ebbw Vale Town with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it occurs. Throw in rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up around Glyncoed
- A green handle for unleaded and black for diesel is usual in the UK — but not on every forecourt. Go by the label on the petrol pump, not the colour.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of cars state the fuel there.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of meaning to remember, for a household with one of each.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems silly. It works.
- While you're thinking about something else, this is an easy mistake to make — so put your 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 cars without one. They are a safety net, not a reason to stop reading the pump.
- Stop as soon as you realise. Less petrol in the tank makes a weaker mix. It does not change what to do next, which is still not to fire it up.
Already put petrol in a diesel around Glyncoed?
Short and simple, then, is the order of things. Never crank it, and do not switch the ignition on. The attendants on the forecourt — whether at Tesco itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Ring 0333 366 0103 next, with three answers — the fuel, the approximate volume, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different problem — Glyncoed has a page all for it.
What makes one Glyncoed petrol in a diesel task cost more than the next
There is no honest single price for this, since the four scenarios above are four different tasks. What shifts your cost is chiefly which of them you're in. The ratio counts next, meaning how much of that tank is petrol, followed by the location of your car and whether reaching it is safe for our van.
That is why our engineers ask three questions before costing rather than after: what went in, how much, and whether it's run. Those answers are what change a range into one firm number.
About Glyncoed
Glyncoed is a suburban area situated in the county of Blaenau Gwent, Wales, with a riverside setting and an elevation of 309 metres. Glyncoed lies near the communities of Newchurch, Ebbw Vale, and Carmeltown, and is approximately 16.7 miles from Newport. Glyncoed has a population of around 2841 people and predominantly consists of semi-detached housing.
Across Blaenau Gwent and around Glyncoed: fuel drain cover
Newchurch, Ebbw Vale and Carmeltown are among the locations near Glyncoed that the same vans work, answering petrol in diesel jobs across Glyncoed's NP postcode area. You need not bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
At the petrol pump around Glyncoed, right now?
The best position there is, then — that's where you are. Keep it off. Phone.