Petrol in a Diesel Car in Bank Top: How Worried Should You Be?
Far less than you likely are, if it has not been started. Till your ignition primes the pump, your starter cranks, or the car is driven, petrol in a diesel tank just sits there and does nothing. Which makes the truthful reply to that first Bank Top question — "have I ruined it?" — normally no. To leave the vehicle like that, ring Petrol in Diesel and leave the engine switched off. Further down, this page sets out what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
Inside the engine: what petrol in a diesel really does
Two jobs fall to diesel on its route round a motor. Lubricating comes before burning; it does both. Made to extremely fine gaps, your injectors and the pump rely on your diesel moving through them to keep their surfaces from wearing against one another.
Petrol handles the first task poorly and the second not at all. The clattering comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the fuel system depends on, and any pump running on that mixture is wearing itself.
Put these together and the shape of the issue is clear. The damage is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel problem. Once your pump has been running on that petrol, a mechanical problem has started: whatever is shed by a pump that's wearing down is carried onward to the fuel injectors with your fuel.
Four situations our engineers see around Bank Top: how bad is petrol in a diesel?
The best case there is: filled up, not once started. That petrol is in the tank and just the tank, and the job is a drain and a flush where your car sits. This is the one situation that can only truly take place on a forecourt, because anywhere else the car has been driven to get there.
Started for a second, or only the ignition on. With the system primed, your lines and filter already hold petrol that came from the tank. Normally little more than clearing, rinsing and sorting the fuel filter, so still easy.
Your pump has worked a couple of miles on weakened fuel — that's what driving the car does. Mileage is only half of that; how hard it was driven counts equally. Either way the work includes the tank, the lines, the filter and fresh fuel through the entire system. On the school run to St Thomas' Leesfield CofE Primary School, the miles is small. Getting as far as Manchester, under 10 miles away, makes a very different task — as does any distance on the Broadway, under 3 miles from Bank Top, with your engine running hard all the way.
Driven until it protested. Rattling, a lumpy idle, smoke, a throttle that has gone soft. That is your engine telling you its fuel has stopped acting like diesel. Stop wherever you are — the verge on Foxley Way, a lay-by, a side street — then leave the car there. Permanent damage is very unusual when a car is pulled over early, and the fuel drain and flush that still go first sort it out.
Petrol in a diesel myths Bank Top drivers hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed when you top up — the tank just carries more of the same blend. Percentage is not how a diesel fuel system copes with petrol, whatever that guidance supposes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Protection matters more on current diesels, not less, because their fuel passes through finer parts at higher pressure.
This is the one that fools drivers. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol motor and it usually will not run, so the driver stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile your pump grinds. Fine and running are not the same at all.
Myth: a two-stroke additive lets you to drive home. It was an old workaround, supposed for another fault. It does not put back what petrol has thinned, and the petrol is still inside that tank after that.
The next start draws petrol back round your pump from the lines and the filter, where some of it sits after your engine has run. That's why draining your tank yourself doesn't leave you sorted — a myth. And, a can of petrol filled by the kerbside is genuinely risky.
Why petrol in a diesel occurs so easily
Carelessness is seldom the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol vehicle at all. So the slip runs one way.
Habit and the vehicle getting out of step is how it happens. Any vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. One petrol and one diesel on the drive of the same household. A familiar forecourt with the pumps in a different order. Rushing for a train outside Mossley (Manchester) and filling up en route. Exactly the moment it takes place: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. Throw in a back seat full of children, a phone call or rain, and habit wins.
Next time you fill up around Bank Top: avoiding petrol in a diesel
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is just a hint.
- Plenty of vehicles state the fuel type inside the filler flap or on the cap, and so check there on the first fill in a motor you do not know.
- Mark the key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump. It seems silly and it works.
- Mistakes like this are straightforward to make while your mind is on something else, and so the phone goes away.
- Some diesels have a filler designed to refuse 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 reading the petrol pump.
- Stop as soon as you realise. Less petrol inside that tank makes a weaker mix. It does not change what to do next, which is still not to start it.
Bank Top: already put petrol in a diesel?
Short and simple, then, is the order of things. Do not switch the ignition on, and don't start it. If you're still on the forecourt — Gulf or anywhere else — ask the staff to help you push the car away from the petrol pump. Phone 0333 366 0103 next, with three answers — the fuel, the rough amount, and whether it's run.
If it was AdBlue and not petrol, say so. That is a different issue — corrosion and deposits rather than lost lubrication — and it has its own page for Bank Top.
What makes one Bank Top petrol in a diesel job cost more than the next
Four different jobs lie behind the four scenarios above — which is why there's no honest single price. The scenario itself does most of the work of moving the cost. Where the vehicle is counts too, and whether a van can safely get to it, after the share of petrol to what the tank takes.
That is why our technicians ask three queries before quoting rather than after: what went in, how much, and whether it's run. A range turns into a straight figure when the replies are in.
About Bank Top
Bank Top is a suburban area in Greater Manchester, situated near the River Medlock and overlooking the surrounding countryside from an elevation of 182 metres. Bank Top is characterized by its predominantly terraced housing stock, reflecting the area's historical development as a residential neighbourhood. Bank Top is located approximately 8 miles from Manchester city centre, making it a commuter-friendly location. Bank Top is also close to nearby places such as Salem, Leesbrook, and Leesfield, which provide additional amenities and services.
Across Greater Manchester and around Bank Top: fuel drain cover
Bank Top sits in the OL postcode area, and the teams that answer petrol in diesel calls there work the spots near it as well — Salem, Leesbrook and Leesfield among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations we work, and the car does not need to come to us.
In Bank Top and still at the petrol pump?
No position is better: that is where you now are. Ring, and leave it switched off.