Petrol in a Diesel Car in South Horrington: How Worried Should You Be?
Likely less than you are now — as long as no one has started the car. Till the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just rests there and does nothing. Which makes the honest reply to that first South Horrington question — "have I ruined it?" — normally no. Petrol in Diesel is who to call, with your engine left off, and so it remains that way. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and ways to make sure you don't repeat it.
What petrol in a diesel does to the motor
On its way through a motor, diesel has two jobs. Before it combusts, it lubricates — and then it burns. What keeps the surfaces inside the high-pressure pump and the fuel injectors from grinding against one another is the diesel passing through them — they are built to extremely fine clearances.
Petrol does the first task badly and the second not at all. The knocking comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication the system rests on, and any pump working on such a mix is wearing itself.
The shape of the problem is clear when you put those together. It is movement that does the harm, not contact. Petrol in a tank is a fuel issue. The start of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors downstream.
How bad is petrol in a diesel? Four situations our technicians see in South Horrington
Filled but never started — as good as it gets. The petrol is in the tank and just that tank, and the job is a drain and a flush where the car stands. This is the one situation that can only truly occur at a forecourt, because anywhere else your car has been driven to get there.
A brief spell of running, or just the ignition on. Petrol has left that tank and got to the fuel filter and the fuel lines, since the fuel system has been primed. Normally nothing more than clearing, flushing and seeing to your filter, so still straightforward.
Driven a few miles. Now your pump has spent these miles running on thinned fuel. The work is that tank, the fuel lines, the filter and fresh fuel through the entire system, and how hard the car was driven counts as much as how far. Driving the children to Horrington Primary School is one sort of trip. Driving as far as Wells, under 3 miles away, makes a very different task — as does any distance on the M5, under 15 miles from South Horrington, with your engine working hard all the way.
Driven on till it protested — rattling, smoke, a ragged idle, a dead throttle. The fuel is not acting like diesel any more, and the motor is telling you. Stop on the spot — on the verge on Gilbert Scott Road, at the kerb, down a side road — and do not move it. The drain and flush still go first, and they deal with it: if a car is stopped soon, lasting damage is very uncommon.
What South Horrington motorists get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It doesn't. Topping up takes out nothing; it gives you a bigger tank of the same mixture. A diesel fuel system doesn't accept petrol by percentage in the way that advice supposes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Protection counts more on current diesels, not less, since their fuel runs through finer parts at higher pressure.
This is the one that catches people. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol engine and it generally will not run, and so the driver stops — and the damage stops with them. Feed petrol to a diesel and it generally starts, idles and drives away as if nothing happened — all while its pump wears. Running is not the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. What petrol has weakened stays diluted, and that petrol remains in your tank anyway.
The next start sends petrol back round your pump from the lines and the filter, where some of that sits once the engine has been run. That is why draining your tank yourself doesn't sort it — a myth. On top of that, petrol cleared into a can by the road is genuinely hazardous.
Why petrol in a diesel takes place at all
A careless moment is seldom the cause, and no one means to do it. The petrol nozzle is the smaller of the two and slips 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.
It takes place when habit and your car stop matching. Any car that is new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the driveway. A forecourt you know, only with its pumps arranged differently. Filling up in a rush on the way to Castle Cary, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Tiguan in front of you on the forecourt for its first tank — that's when. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Next time you fill up in South Horrington: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is just a hint.
- In a car you do not know, look inside the flap over the filler or at the cap before the first fill: plenty of vehicles state the fuel there.
- One of each in the household? Mark the key to your diesel — a coloured fob, a sticker — because intending to remember is not enough.
- "Diesel", out loud, before you pick up the nozzle — every time a new or hired car gets its first tank. It sounds daft. It does the trick.
- Mistakes like this are easy to make while your mind is on something else, so the phone goes away.
- Some diesels have a filler built to reject a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- Spotting it halfway? Stop there and then. A weaker mixture follows from less petrol inside your tank, yet your next step remains the same: don't fire it up.
South Horrington: already put petrol in a diesel?
Then the order of things is brief. Leave it unstarted, with the ignition off as well. If you are still at the forecourt — BP or anywhere else — ask the staff to help you push the vehicle clear of the petrol pump. Then phone 0333 366 0103 and tell us what went in, roughly how much, and whether it has run.
Corrosion and deposits form the issue with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own South Horrington page.
What makes one South Horrington petrol in a diesel task cost more than the next
Four different jobs sit behind the four situations above — which is why there's no fair single price. Chiefly, the cost shifts with which one you are in. Next it is the proportion — how much petrol got in against how much that tank takes — and after that where the car is and whether a technician can get to it safely.
That is why our technicians ask three questions before costing rather than after: what was put in, how much, and whether it has run. Those replies are what change a range into one firm number.
About South Horrington, for a moment
South Horrington is a small village in Somerset, situated near the city of Wells and surrounded by other nearby villages such as East Horrington and West Horrington. South Horrington sits at an elevation of 86 metres, with terraced housing being the predominant type of accommodation. South Horrington is located inland, approximately 109 miles from London, and has a population of around 753 residents.
Across Somerset and around South Horrington: fuel drain cover
East Horrington, West Horrington and Dinder are among the spots around South Horrington that the same vans work, answering petrol in diesel jobs across South Horrington's BA postcode area. Our technicians drain where the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In South Horrington and still at the petrol pump?
The best spot there is, then — that's where you are. Call, and keep it turned off.