Should You Worry? Petrol in a Diesel Car in Marston Green
Not started? Then less anxious than you probably feel. Till your ignition primes the pump, your starter turns, or your car is driven, petrol in a diesel tank just rests there and does nothing. Which makes the truthful reply to the first Marston Green question — "have I wrecked it?" — normally no. Leave the motor off then phone Petrol in Diesel — that is how you keep it like that. What petrol actually does to a diesel, how to judge how far it has gone, and how to stop it from happening again: that's the rest of this page.
Inside the engine: what petrol in a diesel does
Diesel does two jobs on its way through a motor. It burns, and before it ignites it lubricates. Your high-pressure pump and the injectors are made to very fine tolerances, and the diesel passing through them is what stops those surfaces from grinding against one another.
The second task petrol does not do at all, and the first it does badly. It is thinner than diesel and takes away the protection your fuel system hinges on, so a pump running on a petrol mix is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the rattling comes from.
The shape of the issue is plain once you put those together. The damage is done by movement, not by contact. A tank with petrol in it is a fuel fault. Whatever a worn pump sheds goes on, carried by your fuel, into your injectors further along, which is why a pump that has been working on that petrol is where a mechanical fault begins.
Marston Green, petrol in a diesel: four situations, from mild to serious
The best case there is: filled up, never started. That petrol is inside the tank and just the tank, and the task is a drain and a flush where the vehicle sits. This is the one scenario that can only truly occur at a forecourt, since anywhere else your car has been driven to get there.
Ignition on, or started for a moment. The system has been bled, and so petrol has left that tank and got to the fuel filter and the fuel lines. Still generally easy: drain, flush, and the fuel filter dealt with.
Your pump has spent a few miles on thinned fuel — that is what driving it does. How hard your car was driven matters as much as how far, and the work covers that tank, your lines, the fuel filter and fresh fuel through the whole circuit. On the school run to Marston Green Junior School, the mileage is short. Getting as far as Birmingham, under 10 miles away, makes a very different task — as does any miles on the M42, under 3 miles from Marston Green, with your engine running hard the whole time.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone ragged. The fuel is not acting like diesel any more, and the engine is telling you. Whether it's the verge on Land Lane, a lay-by or a side road, stop where you are then leave it. Permanent damage is very uncommon when a vehicle is stopped early, and the drain and flush that still go first sort it out.
Stories Marston Green drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a bigger tank, still the same mix. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite holds. Myth: "A current diesel can cope with a bit of petrol." Protection counts more on current diesels, not less, because their fuel runs through finer parts at higher pressure.
This is the one that fools people. Myth: "If it starts and drives, there is no damage done." A petrol engine fed diesel normally will not run, so the motorist stops and the harm stops with them. While the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the vehicle home." It is an old workaround for a distinct issue. None of what petrol weakened is put back by it — and later, the tank still holds that petrol.
The next start sends petrol back round the pump from the lines and the fuel filter, where some of it sits once your engine has run. That's why a DIY tank drain does not sort it — a myth. It's also genuinely hazardous to drain petrol into a can at the roadside.
How does petrol in a diesel take place?
On purpose? Never. Through carelessness? Rarely, if ever. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol vehicle at all. The forecourt makes it simple, and the slip runs one way.
Routine and the vehicle falling out of step is when it takes place. Hire cars, courtesy cars, and motors that are new to you. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Racing for a train at the nearest station and filling up en route. Precisely the moment it takes place: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. With rain, a call coming in, or a car full of children to deal with, the hand just does what it has always done.
Preventing petrol in a diesel next time you fill up around Marston Green
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on each forecourt. The label is what counts.
- The first fill in a strange car is the time to check the filler flap — on it, or on the cap, plenty of cars state the fuel they take.
- One of each in the house? Label your key to the diesel — a coloured fob, a sticker — because intending to remember isn't enough.
- It seems silly and it works: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Thinking about something else is when this becomes an easy mistake to make, and so put the phone away and keep your mind on the pump.
- Some diesels come with a filler designed 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.
- As soon as you realise, stop: less petrol inside that tank makes a thinner mixture. What to do next does not change, though — still do not fire it up.
Put petrol in a diesel around Marston Green already?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. Yet on the forecourt, at BP or anywhere else? Ask the attendants to help you push the car clear of the petrol pump. Ring 0333 366 0103 next, with three facts — your fuel, the approximate volume, and whether it's run.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and read its own Marston Green page.
Why one petrol in a diesel job in Marston Green costs more than another
An honest single price does not exist here: four situations, four separate jobs. The scenario itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a proportion of what your tank takes, then the spot the vehicle is in and whether our van can reach it safely.
Ahead of any quote, not after, come three questions: your fuel that went in, its volume, and whether it has run. That is why. The replies change a range into a straight figure.
About Marston Green itself
Marston Green is a suburban area in the West Midlands, situated near the River Cole and close to the cities of Birmingham and Coventry. Marston Green has a mix of semi-detached housing and local amenities, with nearby places including Chelmsley Wood, Fordbridge, and Tile Cross. Marston Green is located about 6.6 miles from Birmingham city centre and 95.6 miles from London.
Across West Midlands and around Marston Green: fuel drain cover
Marston Green rests in the B postcode area, and the vans that answer petrol in diesel jobs there work the spots around it as well — Chelmsley Wood, Fordbridge and Tile Cross among them. A forecourt, a supermarket car park, a lay-by or your own driveway are all locations our technicians work, and the vehicle does not need to come to us.
In Marston Green and still at the pump?
The best spot there is, then — that's where you are. Turned off it remains; then ring.