Ton-Teg: Petrol in a Diesel Car? How Worried to Be
If it hasn't been started, worry less than you likely are. Everyone around Ton-Teg begins with "have I ruined it?", and the fair answer is normally no: petrol left in your tank of a diesel stays harmless until priming, cranking or driving pulls it into your fuel system. To keep the car that way, call Petrol in Diesel then leave the motor switched off. What petrol really does to a diesel, how to judge how far it's gone, and how to stop it from happening again: that is the rest of this page.
The motor and petrol in a diesel: what happens
On its way through an engine, diesel does two tasks. It protects first, and after that does it burn. Designed to extremely fine clearances, the fuel injectors and your pump depend on the diesel moving through them to keep their surfaces from wearing against one another.
Of those two jobs, petrol manages the first badly and the second never. It is runnier than diesel and strips away the protection the fuel system hinges on, and so a pump running on a petrol mix is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the clattering comes from.
The shape of the trouble is clear once you put those together. Contact does not do the damage — movement does. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, carried by your fuel, into the injectors downstream, which is why a pump that has been working on that petrol is where a mechanical fault starts.
Petrol in a diesel around Ton-Teg: how bad is it? Four cases
Filled but not once started — the best it gets. On a forecourt, and really only there, the petrol is still limited to your tank — since everywhere else the vehicle was driven to get to it. The job is emptying and cleaning on the spot.
Started for a moment, or just the ignition on. Petrol has come out of your tank and got to the filter and the lines, because the system has been primed. That is normally still a simple task — a drain, a flush, and the filter seen to.
Driven a couple of miles. Now the pump has spent these miles labouring on diluted fuel. The work is the tank, the fuel lines, the fuel filter and clean fuel through the whole circuit, and how hard the car was driven counts as much as how far. Short trips, such as the school run to the local primary school, are one thing. A run as far as Cardiff, under 10 miles away, is a very different task. So is any distance on the M4, under 5 miles from Ton-Teg, where your engine has been working hard the whole time.
Driven till it complained. Rattling, a ragged idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer acting like diesel. Leave it wherever it has stopped: a lay-by, a side street, the verge on Heol Salem. The drain and flush still go first, and they sort it out: when a vehicle is pulled over early, permanent damage is very unusual.
Ton-Teg motorists and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. A fuller tank of the same mix is all you get, because topping up takes out nothing. That advice assumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through more precise parts: that's how a current diesel moves its fuel, so the lubrication matters for more, not less.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. A petrol engine fed diesel generally will not run, so the motorist 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 the while its pump is wearing. Running doesn't mean fine.
Myth: a two-stroke additive lets you to drive home. It is an old fix, meant for another fault. It doesn't put back what petrol has diluted, and that petrol is still in your tank later on.
Myth: "Drain that tank yourself and you're sorted." Once your engine has run, some of the petrol is no longer inside that tank: it's in your filter and the fuel lines, and it goes straight back through the pump at the next start. It's also truly hazardous to drain petrol into a can at the kerbside.
Why petrol in a diesel takes place at all
No one does it on purpose, and it is rarely carelessness. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it simple, and the slip runs one way.
When habit and your car stop matching, it takes place. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. A train to catch, and a hurried fill on the way to Trefforest Estate. A new-to-you diesel Renault Clio, its first fuelling, and a driver accustomed to petrol: exactly when it happens. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Ton-Teg motorists: how to avoid petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a hint.
- In a vehicle you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors state the fuel there.
- One of each in the household? Mark your key to your diesel — a bright fob, a sticker — since intending to remember isn't enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car needs its first tank. It sounds silly. It works.
- Put the phone away. This is an easy mistake to make while you're thinking about something else.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Noticing it halfway? Stop there and then. A weaker mix follows from less petrol in the tank, but your next stage stays the same: do not crank it.
Petrol already in a diesel in Ton-Teg? Begin here
Then, there's only a short order of things. Do not turn your ignition on, and do not fire it up. Ask the attendants to help you roll it clear of the pump if you're still at the forecourt, whether that's Esso or somewhere else. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it has been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different issue — Ton-Teg has a page just for it.
Why one petrol in a diesel job in Ton-Teg costs more than another
A fair single quote doesn't exist here: four situations, four separate jobs. Chiefly, your cost shifts with which one you're in. Where your car is matters too, and whether a technician can safely reach it, after the share of petrol to what the tank holds.
What was put in, how much, and if it's run — three queries we ask before quoting, not after, for precisely that reason. Given the replies, you get a straight figure rather than a range.
About Ton-Teg itself
Ton-Teg is a suburban area in Rhondda Cynon Taf, situated near the riverside at an elevation of 96 metres. Ton-Teg lies close to the nearby communities of Church Village and Upper Church Village, and is within commuting distance of Cardiff, the capital city of Wales. Ton-Teg is characterized by its predominantly semi-detached housing stock, reflecting the residential development of the area.
Fuel drain cover across Rhondda Cynon Taf, Ton-Teg included
The teams answering petrol in diesel call-outs around Ton-Teg, in the CF postcode area, equally work the spots around it, Church Village, Dyffryn Dowlats and Upper Church Village included. You need not bring the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Ton-Teg: still at the petrol pump?
The best place there is, then — that is where you are. Keep it off. Ring.