Maines Batch: Petrol in a Diesel Car? How Worried to Be
Provided it has not been started, you can worry far less than you probably are. Till your ignition primes the pump, the starter cranks, or the car is driven, petrol in a diesel tank simply waits there and does nothing. Which means the honest reply to the first Maines Batch question — "have I ruined it?" — usually no. Keep it like that: leave your engine off and ring Petrol in Diesel. Below, this page sets out what petrol actually does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
The motor and petrol in a diesel: what happens
Two jobs fall to diesel on its journey through a motor. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure pump and the fuel injectors from wearing against each other is the diesel passing through them — they're designed to extremely fine tolerances.
Petrol handles the first task poorly and the second not at all. The clattering comes from petrol being designed not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection the fuel system rests on, and any pump running on that mix is wearing itself.
The shape of the trouble is plain when you put those together. It is movement that causes the harm, not contact. Where the petrol is only inside the tank, it is a problem of fuel, nothing more. Whatever a worn pump sheds goes on, borne by the fuel, into the injectors downstream, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Maines Batch, petrol in a diesel: four situations, from mild to serious
Filled up, and not started: no case is better. Only your tank has petrol in it, so the task is clearing the tank and flushing your system where the car sits. This situation can only really take place at a forecourt: anywhere else, the vehicle got there by being driven.
Your ignition switched on, or a short start. Petrol has left that tank and got to your filter and the fuel lines, since the fuel system has been bled. Usually little more than draining, cleaning and seeing to the fuel filter, and so still simple.
Driven a couple of miles. Now the pump has spent those miles labouring on weakened fuel. Tank, lines, filter, then clean fuel run through the entire circuit: that's this work, and the way your car was driven matters as much as the mileage. The school run to Wrington Church of England Primary School is one thing. Very different once more: a run to Bristol, under 10 miles away, or some mileage on the M5, under 5 miles from Maines Batch, where the engine kept running hard.
Driven on till it complained — rattling, smoke, a ragged idle, a dead throttle. The engine is telling you your fuel is no longer acting like diesel. Whether it's the verge on Ropers Lane, a lay-by or a side street, stop there then leave it. What comes first is still the drain and flush, and that takes care of it, with permanent damage very unusual when a vehicle is stopped quickly.
Maines Batch people and the petrol in a diesel myths they hear
False: topping up to full with diesel makes it fine. It doesn't. Topping up removes nothing; it gives you a fuller tank of the same mixture. That advice assumes a diesel fuel system handles petrol by percentage. It does not.
If anything, the reverse holds. Myth: "A current diesel can cope with a bit of petrol." A modern diesel runs its fuel through more precise components at higher pressure, which makes the protection matter more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that catches drivers. Diesel in a petrol motor normally leaves a motor that will not run: the driver stops, and so does the damage. A diesel fed petrol usually starts, idles and drives away as though nothing has happened, while the pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an old workaround for a different issue. The petrol is still inside that tank afterwards, and whatever it has weakened is not put back.
The next start sends petrol back round your pump out of the lines and the fuel filter, where some of it sits after the motor has run. That's why draining your tank yourself doesn't leave you sorted — a myth. Besides, petrol emptied into a can by the road is truly dangerous.
How does petrol in a diesel occur?
Nobody does it on purpose, and it is rarely carelessness. 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 vehicle at all. The forecourt makes it simple, and the error runs one way.
Routine and the car falling out of step is how it happens. A new car, a hire car or a courtesy car. One petrol and one diesel on the driveway of the same household. The pumps in a different order on a familiar forecourt. Filling up in a rush on the way to Yatton, with a train to catch. A new-to-you diesel BMW 3 Series, its first fuelling, and a motorist accustomed to petrol: precisely when it happens. With rain, a call arriving, or children to deal with, your hand just does what it always has.
Maines Batch people: how to avoid petrol in a diesel next time
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what counts.
- Many motors state the fuel type inside the filler flap or on the cap, so check it on your first fill in any motor you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key when a home has one of each. So label it.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It sounds silly and it does the trick.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels come with a filler built to reject a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Less petrol means a thinner blend, so stop as soon as you notice — though remembering that the next step is unchanged. It's still not to crank it.
Petrol already in a diesel in Maines Batch? Begin here
Then the order of things is short. Starting it is out, and so is switching on the ignition. Ask the attendants to help you push it away from the pump if you are still at the forecourt, whether that is Esso or somewhere else. Then ring 0333 366 0103 and tell us what got in, roughly how much, and if it has run.
Corrosion and deposits form the problem with AdBlue, whereas petrol brings lost protection. So if it was AdBlue, say so — and read its own Maines Batch page.
Why one petrol in a diesel job in Maines Batch costs more than another
A fair single price doesn't exist here: four situations, four separate jobs. What moves the cost is mostly which of them you're in. Next it's the share — how much petrol was put in against how much that tank takes — and then where the car is and whether our van can reach it safely.
Three questions come first, before quoting, instead of after — what was put in, how much, has it run — and that is the reason. Given the answers, you get a straight figure rather than a range.
About Maines Batch itself
Maines Batch is a suburban area in Somerset, situated inland at an elevation of around 50 metres, approximately 9 miles from Bristol. Maines Batch comprises predominantly detached housing and is home to a population of around 1630 residents. Maines Batch is located near other small settlements such as Wrington, Butts Batch, and Udley, in the South West region of England. Maines Batch is also within commuting distance to major cities, with London being around 114 miles away.
Across Somerset and around Maines Batch: fuel drain cover
Petrol in diesel call-outs in Maines Batch — part of the BS postcode area — go to vans that also cover the spots around it, Wrington, Butts Batch and Udley included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers work, and your car doesn't need to come to us.
Still at the pump in Maines Batch?
Then you're in the best position there is. Ring, and keep it switched off.