How Worried Should You Be? Petrol in a Diesel Car in Cubbington
Probably less than you are now — provided nobody has started the car. Till the ignition primes the pump, your starter cranks, or the car is driven, petrol in a diesel tank simply waits there and does no harm. Which means the truthful reply to the first Cubbington question — "have I wrecked it?" — usually no. Leave the engine off then call Petrol in Diesel — that is how you keep it like that. Keep reading 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 repeat it.
Inside your engine: what petrol in a diesel really does
Passing through an engine, diesel is doing two jobs at once. Lubricating comes before burning; it does both. Built to very fine clearances, the fuel injectors and the pump depend on the diesel flowing through them to stop their surfaces wearing against one another.
Petrol does the first task badly and the second not at all. It is runnier than diesel and strips away the protection the fuel system hinges 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 opposite of what a diesel needs from its fuel. That's where the rattling comes from.
Combined, those leave the shape of the issue plain. Not contact but circulation is what causes the damage. Petrol in the tank is a fuel problem. Whatever a worn pump sheds travels on, borne by the fuel, into the injectors further along, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Four situations our technicians see around Cubbington: how serious is petrol in a diesel?
Filled but never started — the best it gets. That petrol is in the tank and just the tank, and the job is a drain and a flush where the vehicle sits. This is the one scenario that can only truly occur on a forecourt, as anywhere else the car has been driven to get there.
The ignition turned on, or a short start. With your system primed, the fuel lines and filter already hold petrol that has come from your tank. Normally nothing more than emptying, purging and sorting the filter, so still easy.
Driven a few miles. Now your pump has spent these miles working on thinned fuel. Tank, lines, filter, then fresh fuel put through the entire system: that's the work, and the way your car was driven counts as much as the mileage. Short trips, such as the school run to Cubbington CofE Primary School, are one thing. Any miles on the M40, under 10 miles from Cubbington, means your engine has worked hard throughout, and a run to Coventry, under 10 miles away, is a very different task too.
Driven until it complained. Clattering, a ragged idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the engine is telling you. Leave it where it has stopped: a lay-by, a quiet street, the verge on Hill Crest. The fuel drain and flush-through still go first, and they take care of it: if a vehicle is stopped soon, long-term damage is very uncommon.
Stories Cubbington motorists hear about petrol in a diesel
"Top it up the rest of the way with diesel and it'll be fine" — a myth. It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. The assumption behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the opposite. Lubrication matters more on current diesels, not less, because their fuel passes through more precise components at higher pressure.
"It starts, it drives, so no harm done" — the myth that catches most drivers than any other. Diesel in a petrol motor normally leaves a motor that will not run: the motorist stops, and so does the damage. Whilst the pump wears, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different fault. What petrol has weakened remains diluted, and the petrol stays inside that tank anyway.
The next start sends petrol back round the pump from the lines and the filter, where some of that sits after the motor has run. That's why draining your tank yourself doesn't leave you sorted — a myth. It is also genuinely risky to drain petrol into a can by the roadside.
Petrol in a diesel: how does it occur?
It's seldom carelessness, and nobody does it on purpose. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly won't fit a petrol vehicle. That is how the forecourt makes it straightforward.
The moment routine stops matching the car is the moment it occurs. A car that's new to you — a hire car, on loan as a courtesy car, or just bought. Two vehicles on one drive, one petrol, one diesel. Your ordinary forecourt, its pumps now in a different order. Racing for a train outside Leamington Spa and filling up en route. Years of petrol vehicles behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that's when. Add rain, a phone call or a back seat full of kids, and the hand does what it has always done.
Next time you fill up around Cubbington: avoiding petrol in a diesel
- Green for unleaded and black for diesel is normal in the UK — yet not on every forecourt. Go by the label on the petrol pump, not the colour.
- Plenty of motors state the fuel type inside the filler flap or on the cap, so check there on your first fill in a vehicle you do not know.
- One of each in the household? Mark your key to your diesel — a bright fob, a sticker — since meaning to remember isn't enough.
- It sounds daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the pump.
- Put the phone away. This is an easy mistake to make while you are thinking about something else.
- 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 reading the petrol pump.
- Less petrol means a thinner mixture, and so stop the moment you notice — while remembering that the next stage is unchanged. It is still not to crank it.
Already put petrol in a diesel in Cubbington?
The order of things is short, then. Do not turn the ignition on, and don't crank it. Yet on the forecourt, at Shell or anywhere else? Ask the attendants to help you push the vehicle clear of the pump. Then ring 0333 366 0103 and tell us what got in, roughly how much, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a different fault — Cubbington has a page all for it.
Cubbington petrol in a diesel tasks: why one costs more than another
Four different tasks lie behind the four scenarios above — which is why there is no fair single quote. Which of them you are in is mostly what shifts the cost. Two things follow that: the petrol that got in as a share of what that tank holds, then the spot the car is in and whether our van can get to it safely.
Three questions come first, before any quote, instead of after — what got in, how much, has it run — and this is the reason. A range becomes a straight figure once the answers are in.
About Cubbington
Cubbington is a village in Warwickshire, situated on the River Leam, with Cubbington being close to the city of Coventry and surrounded by nearby places such as Lillington and Weston under Wetherley. Cubbington sits at an elevation of 87 metres, with Cubbington's riverside setting contributing to its scenic views. Cubbington has a population of around 1971 residents, with Cubbington's housing stock predominantly comprising semi-detached homes.
Across Warwickshire and in Cubbington: fuel drain cover
Petrol in diesel jobs around Cubbington — part of the CV postcode area — go to teams that likewise cover the locations round it, Lillington, Weston under Wetherley and Campion Hills included. The car does not need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
Still at the petrol pump around Cubbington?
Then, you could not be in a better place. Keep the vehicle turned off, then ring.