How Worried Should You Be? Petrol in a Diesel Car in Hook End
Far less than you likely are, if it has not been started. Everyone around Hook End begins with "have I wrecked it?", and the honest answer is generally no: petrol left in that tank of any diesel stays harmless until priming, cranking or driving draws it into your fuel system. To leave it like that, call Petrol in Diesel and leave your engine switched off. What petrol really does to a diesel, how to judge how far it's travelled, and how to stop it from happening a second time: that is the rest of this page.
The motor and petrol in a diesel: what goes on
Passing through an engine, diesel does two jobs at the same time. It lubricates first, and after that does it burn. The high-pressure pump and your injectors are made to extremely fine gaps, and your diesel passing through them is what keeps those surfaces from grinding against each other.
Petrol handles the first job poorly and the second not at all. It's runnier than diesel and removes the lubrication the fuel system rests on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the reverse of what a diesel needs from its fuel. That's where the clattering comes from.
Seen together, they show what shape the problem has. Not contact but movement is what does the harm. Where the petrol is only inside that tank, it is an issue of fuel, nothing more. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to your injectors further on.
How serious is petrol in a diesel? Four scenarios we see in Hook End
Filled up, never started. The best case there is. On a forecourt, and truly only there, that petrol is still limited to the tank — since anywhere else the vehicle was driven to get to it. The job is draining and purging on the spot.
A moment's running, or merely your ignition on. The system has been bled, and so petrol has left the tank and reached the filter and your lines. Still generally easy: drain, flush, and the fuel filter dealt with.
Driven a couple of miles. Now the pump has spent these miles working on diluted fuel. Tank, lines, filter, then clean fuel run through the entire system: that is the work, and the way the car was driven counts as much as the miles. A school run to Doddinghurst Infant School is one thing. Very different again: a run to Chelmsford, under 10 miles away, or some distance on the M25, under 5 miles from Hook End, where your engine kept running hard.
Driven on until it complained — clattering, smoke, a lumpy idle, a soft throttle. That is the motor telling you its fuel no longer is acting like diesel. Whether it's the verge on Hook End Lane, a lay-by or a side road, stop where you are then leave it. What comes first is still the fuel drain and flush, and that takes care of it, with permanent damage very unusual if a car is pulled over early.
What Hook End motorists get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It won't. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. That guidance presumes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Smaller components and higher pressure are the way a modern diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no harm done." The driver of a petrol engine fed diesel usually stops, because it will not run, and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump wears. Running doesn't mean fine.
An old fix for a different issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol thinned gets put back by it — and afterwards, that tank still contains that petrol.
If the engine has been run, part of that petrol is in the filter and the lines, not that tank — and your next start pulls it right back through the pump. So the myth "drain that tank yourself and you are sorted" does not hold. Also, a can of petrol filled at the roadside is genuinely hazardous.
How petrol ends up: petrol in a diesel
Carelessness is rarely the cause, and nobody means to do it. The forecourt makes it easy: the petrol nozzle is the smaller 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 motor at all. So the mistake runs one way.
Routine and the vehicle falling out of step is when it occurs. A car that's new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. Your usual forecourt, its pumps now in a different order. Racing for a train at Shenfield and fuelling up en route. Years of petrol vehicles behind you, a diesel BMW 3 Series in front of you on the forecourt for its first tank — that is when. Your hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up in Hook End: avoiding petrol in a diesel
- The label is what matters, and so read the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- Plenty of cars state the fuel type inside your filler flap or on the cap, and so check there on your first fill in a motor you don't know.
- Good intentions do less than a sticker or a fob in a bright colour on the diesel's key if a home has one of each. So mark it.
- It seems daft and it does the trick: on the 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 tuck the phone away then keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and aftermarket devices exist for the rest. Count it as a backstop, then keep checking the petrol pump.
- Less petrol makes a thinner blend, so stop as soon as you notice — though remembering that the next step is unchanged. It's still not to start the vehicle.
Petrol already in a diesel in Hook End? Begin here
Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off as well. Yet at the forecourt, at Applegreen or anywhere else? Ask the staff to help you push the car away from the pump. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate issue — Hook End has a page all for it.
One petrol in a diesel task in Hook End costs more than another. Why?
The four situations above are four separate jobs, so no single quote for this would be honest. Which of them you're in is chiefly what shifts your cost. Where the car is matters too, and whether a technician can safely reach it, after the proportion of petrol to what the tank takes.
Three queries come first, before quoting, rather than after — what was put in, how much, has it run — and this is the reason. Their replies are what change a range into one firm number.
About Hook End and its setting
Hook End is a small village in Essex, situated inland at an elevation of around 95 metres, and is located near the larger city of Chelmsford. Hook End has a population of approximately 946 residents and is characterised by predominantly detached housing. Hook End is also close to other nearby places such as Stondon Green, Tips Cross, and Wyatts Green, and is about 21.8 miles from London.
Fuel drain cover in Hook End and across Essex
Stondon Green, Tips Cross and Wyatts Green are among the places around Hook End that the same vans work, answering petrol in diesel call-outs across Hook End's CM postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our engineers drain, and the vehicle does not need to move to us.
In Hook End and still at the pump?
The best place there is, then — that is where you are. Ring, and keep it turned off.