Maidenbrook: Petrol in a Diesel Car? How Worried to Be
Less than you probably are, provided it has not been started. Till your ignition primes the pump, your starter turns, or your car is driven, petrol in a diesel tank just sits there and does nothing. Which makes the honest reply to the first Maidenbrook query — "have I ruined it?" — normally no. To keep it like that, call Petrol in Diesel then leave the motor switched off. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and the way to make sure you never do it again.
Your engine and petrol in a diesel: what happens
Two jobs fall to diesel on its journey round a motor. Lubricating comes before burning; it does both. Designed to extremely fine gaps, the fuel injectors and the pump rely on the diesel flowing through them to stop their surfaces wearing against one another.
Poorly at the first, not at all at the second: that's petrol. A pump running on a petrol blend is wearing itself out, because petrol is runnier than diesel and takes away the lubrication the fuel system depends on. Petrol is also designed to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where any knocking comes.
Together, those leave the shape of the trouble plain. Not contact but movement is what causes the harm. All a tank with petrol in it amounts to is a fuel issue. Whatever a worn pump sheds travels on, carried by your fuel, into your injectors further along, which is why a pump that has worked on the petrol is where a mechanical issue begins.
Maidenbrook, petrol in a diesel: four situations, from mild to significant
Filled but not once started — as good as it gets. On a forecourt, and really only there, that petrol is still limited to that tank — because everywhere else your car was driven to reach it. The task is emptying and cleaning on the spot.
The ignition switched on, or a brief start. With your system primed, the fuel lines and filter now hold petrol that has come from your tank. Normally nothing more than draining, flushing and sorting the filter, and so still simple.
Those few miles on the road meant your pump running on fuel diluted by petrol the whole way. The work is that tank, your lines, the filter and clean fuel through the entire system, and how hard your car was driven matters as much as how far. On the school run to Nerrols Primary School and Nursery, the miles is short. Very different once more: a run to Wells, under 25 miles away, or some miles on the M5, under a mile from Maidenbrook, where the motor never stopped running hard.
Driven until it protested. Knocking, a lumpy idle, smoke, a throttle that has gone soft. That's your motor telling you its fuel has stopped acting like diesel. Leave it where it has stopped: a lay-by, a quiet street, the verge on Waterleaze. A car pulled over quickly very seldom has permanent damage, as the drain and the flush-through, which still go first, take care of it.
What Maidenbrook people get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — that tank just holds more of the same mixture. That advice assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Not so: a modern diesel copes with a bit of petrol. Rather, the reverse. A newer diesel sends its fuel through finer parts at higher pressure, which makes the protection count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Diesel in a petrol motor generally leaves a motor that won't run: the motorist stops, and so does the damage. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump wears. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. It doesn't put back what petrol has thinned, and the petrol is still inside your tank later on.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, waiting to go straight back through your pump on the next start. Also, a can of petrol drained by the kerbside is genuinely hazardous.
Why petrol in a diesel takes place at all
No one does it on purpose, and it is rarely carelessness. A diesel nozzle mostly won't fit a petrol motor, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one error simple, and just in one direction.
Routine and the vehicle getting out of step is how it happens. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. Your normal forecourt, its pumps suddenly in a different order. A rushed fill on the way to Taunton with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: exactly when it occurs. With rain, a call coming in, or children to deal with, the hand just does what it always has.
Maidenbrook motorists: how to avoid petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of cars print the fuel type there.
- Good intentions count for less than a sticker or a fob in a bright colour on your diesel's key if a house has one of each. So mark it.
- Before the nozzle leaves the pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Daft, yes, yet it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Add-on devices are available for cars without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a backstop at best, never a reason to stop checking the label.
- Stop as soon as you realise. Less petrol in that tank means a thinner mix. It does not change what to do next, which is still not to start the car.
Petrol already in a diesel in Maidenbrook? Start here
The order of things is brief, then. Starting it is out, and so is switching on the ignition. The staff at the forecourt — whether at Asda itself or wherever you filled up — will usually help push it clear of the pump if you ask. Next, 0333 366 0103. We will ask what got in, roughly how much, and if it has been run.
Say so if it was AdBlue rather than petrol: it's a different fault, with its own page for Maidenbrook, because AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel task around Maidenbrook costs more than another
There's no honest single quote for this, because the four scenarios above are four different jobs. The scenario itself does most of the work of moving your cost. The ratio matters next, meaning how much of your tank is petrol, and then the position of your car and whether reaching it is safe for a technician.
Three queries come first, before any quote, instead of after — what got in, how much, has it run — and that is the reason. The replies change a range into a straight figure.
About Maidenbrook, for a moment
Maidenbrook is a suburban area in Somerset, situated on the riverside at a low elevation of around 16 metres. Maidenbrook lies near several other local places, including Bathpool, Priorswood, and Monkton Heathfield, and is approximately 22 miles from the city of Wells. Maidenbrook has a population of around 2018 people and is characterised by predominantly detached housing. Maidenbrook is also within commuting distance of larger cities, being around 131 miles from London.
Fuel drain cover around Maidenbrook and across Somerset
Petrol in diesel jobs in Maidenbrook — part of the TA postcode area — go to teams that likewise cover the locations around it, Bathpool, Priorswood and Monkton Heathfield among them. The car doesn't need to move to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the pump in Maidenbrook?
The best spot there is, then — that's where you are. Keep the vehicle switched off, then ring.