Lee Chapel: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — provided nobody has started the car. Everyone around Lee Chapel starts with "have I wrecked it?", and the honest answer is usually no: petrol resting inside the tank of a diesel stays harmless till priming, cranking or driving draws it into the system. Petrol in Diesel is who to phone, with your motor left off, and so it remains that way. What petrol really does to a diesel, how to judge how far it's gone, and how to keep it from happening again: that is the rest of this page.
Inside your engine: what petrol in a diesel does
On its way through an engine, diesel has two jobs. Before it combusts, it lubricates — and then it combusts. The high-pressure fuel pump and the fuel injectors are designed to extremely fine clearances, and the diesel passing through them is what stops those surfaces from wearing down against one another.
Petrol does the first job badly and the second not at all. A pump running on a petrol mixture is wearing itself out, since petrol is thinner than diesel and takes away the protection your fuel system depends on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where the knocking starts.
Put these together and the shape of the issue is plain. Contact doesn't do the harm — circulation does. A tank with petrol in it is a fuel problem. Whatever a worn pump sheds travels on, borne by your fuel, into the injectors downstream, which is why a pump that has been working on the petrol is where a mechanical problem begins.
Lee Chapel, petrol in a diesel: four situations, from mild to serious
The best case there is: filled up, never started. At a forecourt, and really only there, the petrol is still confined to the tank — because everywhere else the car was driven to reach it. The task is draining and flushing on the spot.
Ignition on, or started for a second. With the system primed, the lines and filter already hold petrol that came from your tank. Normally nothing more than emptying, rinsing and sorting the fuel filter, so still simple.
Your pump has worked a couple of miles on weakened fuel — that's what driving it meant. Miles is only half of that; how hard it was driven matters just as much. Either way the work runs to the tank, the fuel lines, your filter and clean fuel through the entire system. On the school run to St Anne Line Catholic Junior School, the distance is short. A run as far as Chelmsford, under 15 miles away, is a very different task. So is any miles on the M25, under 10 miles from Lee Chapel, where the engine has been labouring hard throughout.
Driven on until it protested — rattling, smoke, a ragged idle, a dead throttle. That's the motor telling you its fuel no longer is acting like diesel. Whether it's the verge on Rise Park, a lay-by or a side street, 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 when a vehicle is stopped quickly.
Lee Chapel people and that petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It does not. A fuller tank of the same mixture is all you get, since topping up takes out nothing. The idea behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. At higher pressure, through finer parts: that is how a modern diesel moves its fuel, so the lubrication counts for more, not less.
The myth that catches motorists off guard: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it generally will not run, so the motorist stops — and the harm stops with them. A diesel fed petrol normally starts, idles and drives away as if nothing has happened, while the pump grinds. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. The petrol is still inside that tank afterwards, and whatever it has diluted isn't put back.
Myth: "Drain that tank yourself and you are sorted." After the motor has been run, some of that petrol is no longer inside your tank: it's in your filter and your lines, and it goes right back through your pump at your next start. Besides, petrol cleared into a can by the road is genuinely dangerous.
Petrol in a diesel: how does it happen?
Nobody does it on purpose, and it's rarely carelessness. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol vehicle at all. The forecourt makes it simple, and the slip runs one way.
The moment habit stops matching your car is the moment it occurs. Hire cars, courtesy cars, and motors that are new to you. One petrol and one diesel on the drive of the same household. Your ordinary forecourt, its pumps suddenly in a different order. A hurried fill on the way to Basildon with a train to catch. Years of petrol vehicles behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that's when. Add a back seat full of kids, a phone call or rain, and habit wins.
Lee Chapel motorists: how to prevent petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — but not on each forecourt. Trust the label on the pump, not the colour.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: many motors state the fuel there.
- One of each in the house? Mark your key to your diesel — a bright fob, a sticker — because intending to remember is not enough.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, so tuck the phone away then keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to reject a petrol nozzle, and add-on devices exist for the rest. Count it as a backstop, then keep checking the petrol pump.
- Stop the moment you notice. Less petrol inside your tank means a thinner mix. It doesn't change what to do next, which is still not to crank it.
Put petrol in a diesel around Lee Chapel already?
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off too. If you are still at the forecourt — BP or anywhere else — ask the staff to help you push the vehicle away from the petrol pump. Call 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a separate issue — Lee Chapel has a page all for it.
Why one petrol in a diesel job around Lee Chapel costs more than another
The four situations above are four different jobs, so no single price for this would be honest. Which of them you are in is chiefly what shifts your cost. Next it's the proportion — how much petrol went in against how much the tank takes — and then where the vehicle is and whether our van can reach it safely.
Ahead of any quote, not after, we ask three queries: the fuel that got in, its amount, and whether it's run. That's why. Their replies are what change a range into one firm number.
About Lee Chapel and where it is
Lee Chapel is a locality in Essex, situated on the riverside at a relatively low elevation of 32 metres. Lee Chapel lies within the Eastern region, approximately 25 miles from London and 11.6 miles from Chelmsford. Lee Chapel has a mix of housing types, but terraced housing is predominant in the area. Lee Chapel is close to other nearby places, including Lee Chapel North, Basildon, and Lee Chapel South.
Across Essex and around Lee Chapel: fuel drain cover
Petrol in diesel calls in Lee Chapel — part of the SS postcode area — go to teams that likewise cover the places round it, Lee Chapel North, Basildon and Lee Chapel South 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 drive.
Still at the petrol pump in Lee Chapel?
Then, you couldn't be in a better position. Switched off it remains; then ring.