Petrol in a Diesel Car in Pencoed: How Worried Should You Be?
Unstarted? Then less worried than you probably are. "Have I wrecked it?" is the first thing anyone around Pencoed asks, and the truthful answer is generally no, because petrol left in a diesel tank hurts nothing until it's drawn through the system — by ignition priming, by your starter, or by being driven. Petrol in Diesel is who to phone, with your motor kept off, and so it remains that way. Read on for three things: the effect petrol has inside a diesel motor, the clues 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 motor?
On its way through a motor, diesel has two jobs. It combusts, and before it combusts it lubricates. Made to very fine clearances, the injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Of these two tasks, petrol manages the first poorly and the second not at all. The clattering comes from petrol being designed not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips away the lubrication the fuel system rests on, and any pump running on such a blend is wearing itself.
Put those together and the shape of the issue is plain. Not contact but circulation is what causes the harm. Petrol in the tank is a fuel problem. After your pump has been labouring on that petrol, a mechanical issue has started: whatever is shed by a pump that's grinding is carried onward to your injectors with the fuel.
Four scenarios our engineers see in Pencoed: how bad is petrol in a diesel?
Filled but not once started — the best it gets. Being at a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held inside your tank alone, it is cleared and purged on the spot, and nothing more is needed.
A moment's running, or merely your ignition on. Once primed, the fuel system has drawn petrol out of your tank up to the fuel filter and your lines. That's normally still an easy task — a drain, a flush, and your filter seen to.
Driven a few miles. Now your pump has spent those miles labouring on thinned fuel. How hard your car was driven counts as much as how far, and the work takes in the tank, the lines, the filter and fresh fuel through the whole circuit. The school run to the local primary school is one matter. Any distance on the M4, under a mile from Pencoed, means the motor has worked hard throughout, and a run to Cardiff, under 15 miles away, is a very different job as well.
Driven on till it complained — knocking, smoke, a lumpy idle, a soft throttle. What you are hearing is your engine signalling fuel that no longer acts like diesel. Whether it is the verge on Heol Y Groes, a lay-by or a side street, stop where you are and leave it. A vehicle stopped soon very rarely has lasting damage, because the fuel drain and the flush, which still come first, take care of it.
What Pencoed motorists get told about petrol in a diesel — and the myths in it
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 it gives, since topping up removes nothing. That guidance presumes a diesel fuel system tolerates petrol by percentage. It does not.
"Modern diesels can handle a little petrol" — a myth, and closer to the reverse. Lubrication matters more on newer diesels, not less, since their fuel runs through smaller parts at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that fools drivers. Diesel in a petrol motor normally means a motor that won't run: the motorist stops, and so does the harm. Feed petrol to a diesel and it normally starts, ticks over and drives away like nothing has happened — all while its pump wears. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It's an old workaround for a separate problem. None of what petrol diluted gets put back by it — and later, the tank still contains that petrol.
Myth: "Drain the tank yourself and you're sorted." After your engine has been run, some of that petrol is no longer in that tank: it's in your filter and your lines, and it goes right back through the pump at the next start. And, a can of petrol filled at the roadside is genuinely dangerous.
How does petrol in a diesel happen?
Carelessness is seldom the cause, and no one means to do it. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol vehicle. That is how the forecourt makes it easy.
It takes place when habit and the vehicle stop matching. Courtesy car, hire car, or a motor that is brand new. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Racing for a train at the nearest station and fuelling up en route. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: precisely when it occurs. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of children.
Next time you fill up around Pencoed: preventing petrol in a diesel
- Green 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 the filler or at the cap before the first fill: many cars print the fuel there.
- Mark 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 meaning to remember.
- It seems daft and it does the trick: on your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to reject a petrol nozzle, and aftermarket devices are available for the rest. Count it as a safety net, and keep checking the petrol pump.
- The moment you notice, stop: less petrol inside that tank means a weaker blend. What to do next doesn't change, though — still don't start the car.
Put petrol in a diesel in Pencoed already?
Short and simple, then, is the order of things. Don't fire it up, and don't switch your ignition on. The staff at the forecourt — whether at Texaco itself or wherever you filled up — will normally help push it away from the pump if you ask. Next, 0333 366 0103. We will ask what was put in, about how much, and if it has been run.
Corrosion and deposits are the trouble with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and read its own Pencoed page.
What makes one Pencoed petrol in a diesel task cost more than the next
There is no fair single quote for this, because the four situations above are four different jobs. Which of them you are in is mostly what moves the cost. Two things follow that: the petrol that was put in as a proportion of what that tank takes, then the place the car is in and whether a van can get to it safely.
What went in, how much, and if it's run — three questions our technicians ask before costing, not after, for precisely that reason. A range becomes a straight figure once the answers are in.
About Pencoed
Pencoed is a town situated on the banks of the River Ewenny in south Wales, with a mix of semi-detached housing and local amenities. Pencoed lies close to the M4 motorway and is near the villages of Penprysg, Felindre, and Llanilid. Pencoed has a population of around 9119 people and is located about 14 miles from Cardiff, the capital city of Wales. Pencoed is also relatively low-lying, with an average elevation of 33 metres above sea level.
Fuel drain cover across Bridgend, Pencoed included
Petrol in diesel calls around Pencoed — part of the CF postcode area — go to vans that also cover the places around it, Penprysg, Felindre and Llanilid among them. No need to bring your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
At the petrol pump around Pencoed, right now?
No position is better: that's where you now are. Switched off it stays; then call.