Should You Worry? Petrol in a Diesel Car in Jericho
If it hasn't been started, you can worry less than you probably are. Until the ignition primes the pump, the starter turns, or your vehicle is driven, petrol in a diesel tank just waits there and does nothing. Which makes the truthful reply to that first Jericho query — "have I ruined it?" — usually no. Keep it like that: leave your engine off and ring Petrol in Diesel. Read on for three things: the effect petrol has inside a diesel motor, the signs of how far it has spread, and ways to make sure you never repeat it.
What petrol in a diesel does to the motor
On its way through an engine, diesel has two tasks. Lubricating comes before burning; it does both. Designed to very fine gaps, the fuel injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Petrol does the first task poorly and the second not at all. The knocking comes from petrol being made 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 away the protection the system depends on, and any pump running on such a mixture is wearing itself.
Together, those leave the shape of the issue clear. Not contact but circulation is what causes the harm. Where that petrol is only inside the tank, it is a fault of fuel, nothing more. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors beyond it.
How serious is petrol in a diesel? Four scenarios we see around Jericho
The best case there can be: filled up, never started. On a forecourt, and genuinely only there, the petrol is still confined to that tank — because everywhere else the car was driven to get to it. The job is draining and cleaning on the spot.
Ignition on, or started for a second. Petrol has come out of the tank and reached your filter and the fuel lines, because your system has been bled. Usually little more than draining, rinsing and sorting the filter, so still easy.
A couple of miles driven, and the pump has spent each of them labouring on diluted fuel. The work is the tank, the fuel lines, the filter and clean fuel through the whole system, and how hard the car was driven matters as much as how far. Short trips, like the school run to St Barnabas' Church of England Aided Primary School, are one thing. Very different again: a run to Oxford, under a mile away, or any miles on the Wheatley Spur, under 10 miles from Jericho, where the motor never stopped running hard.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone ragged. What you are hearing is your motor signalling fuel that no longer acts like diesel. Whether it's the verge on Cardigan Street, a lay-by or a side street, stop where you are and leave it. Long-term damage is very rare when a car is pulled over quickly, and the fuel drain and flush-through that still come first deal with it.
Stories Jericho 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 will be." Nothing is removed by topping up — you're left with a bigger tank, still the same mixture. The assumption behind the advice — that diesel fuel systems tolerate petrol by percentage — is wrong.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." A modern diesel sends its fuel through smaller parts at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there is no damage done." This is the one that fools people. Diesel in a petrol motor normally leaves a motor that won't run: the motorist stops, and so does the damage. Feed petrol to a diesel and it usually starts, ticks over and pulls away as if nothing happened — all the while its pump wears. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive it home." It is an outdated workaround for a distinct fault. None of what petrol diluted is put back by it — and later, that tank still contains that petrol.
Myth: "Drain that tank yourself and you're sorted." Once your engine has run, some of the petrol is no longer in your tank: it is in the fuel filter and your lines, and it goes right back through the pump on the next start. And, a can of petrol drained at the kerbside is truly risky.
How does petrol in a diesel take place?
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
The moment routine stops matching the car is the moment it takes place. Courtesy car, hire car, or a car that's brand new. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. Racing for a train outside Oxford and filling up en route. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you at the forecourt for its first tank — that is when. Add rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Jericho motorists: how to avoid petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, though most generally do. Read the pump's label; the colour is only a hint.
- Inspect the filler flap. Plenty of cars state the fuel inside the flap or on the cap. Look at it on the first fill in any vehicle you do not know.
- Good intentions do less than a sticker or a fob in a vivid colour on your diesel's key if a house has one of each. So label it.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It seems daft and it does the trick.
- While you're thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices are available for cars without one, and some diesels come with a filler that won't accept a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol inside that tank makes a thinner mixture. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel around Jericho already?
Then, there's just a short order of things. Starting it is out, and so is turning on the ignition. If you are still at the forecourt — BP or anywhere else — ask the attendants to help you push the car away from the petrol pump. Then phone 0333 366 0103 and tell us what got in, roughly how much, and whether it has run.
If it was AdBlue and not petrol, say so. That's a different fault — corrosion and deposits instead of lost lubrication — and it has its own page for Jericho.
Jericho petrol in a diesel tasks: why one costs more than another
Four different tasks lie behind the four situations above — which is why there is no honest single quote. What moves the cost is mostly which of them you're in. Next it's the share — how much petrol got in against how much that tank holds — and then where your car is and whether our van can get to it safely.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and this is the reason. Their replies are what change a range into one firm number.
About Jericho and where it is
Jericho is a suburban area in Oxfordshire, situated on the banks of the River Thames, with Walton Manor and Norham Manor nearby. Jericho has a mix of housing types, but is predominantly characterized by terraced homes. Jericho is located very close to Oxford city centre, at an elevation of around 59 metres, and is part of the larger Oxford urban area. Jericho is also within commuting distance of London, approximately 51.9 miles away.
Fuel drain cover across Oxfordshire, Jericho included
Walton Manor, Norham Manor and New Osney are among the spots near Jericho that the same vans work, answering petrol in diesel calls across Jericho's OX postcode area. Our engineers drain where your vehicle is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
In Jericho and still at the pump?
Then you're in the best position there is. Keep it off. Phone.