Petrol in a Diesel Car in Illshaw Heath: How Worried Should You Be?
Probably less than you are now — as long as nobody has started it. Petrol resting in a diesel tank does nothing to your engine till something draws it through the system — the ignition priming your pump, the starter, or driving on its own. So the truthful answer to the first query anyone in Illshaw Heath asks, "have I wrecked it?", is normally no. Keep it that way: leave your motor off and phone Petrol in Diesel. The remainder of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
Your engine and petrol in a diesel: what happens
Two jobs fall to diesel on its route round a motor. It burns, and before it burns it protects. Very fine gaps are built into your injectors and your high-pressure pump, and just the diesel running through stops those surfaces grinding together.
Petrol does the first task poorly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump running on the blend wearing itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Combined, those leave the shape of the trouble plain. Not contact but circulation is what causes the damage. All a tank with petrol in it amounts to is a fuel problem. The beginning of a mechanical problem is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors beyond it.
How serious is petrol in a diesel? Four situations our technicians see around Illshaw Heath
Filled up, never started. The best case there is. Just that tank has petrol in it, and so the job is clearing that tank and flushing the system where your car sits. This scenario can only really occur at a forecourt: anywhere else, the car got there by being driven.
Ignition on, or started for a moment. The fuel system has been primed, and so petrol has left that tank and reached the filter and your lines. Drain, flush, deal with the fuel filter: still normally easy.
Those few miles driven meant your pump working on fuel diluted by petrol throughout. How hard the vehicle was driven matters as much as how far, and the work covers that tank, your lines, the filter and clean fuel through the entire system. Short trips, like the school run to St Patricks Church of England Primary Academy, are one matter. Driving as far as Birmingham, under 10 miles away, makes a very different task — as does any distance on the M42, under a mile from Illshaw Heath, with the motor working hard the whole time.
Driven on until it protested — rattling, smoke, a lumpy idle, a dead throttle. That is your engine telling you its fuel no longer is acting like diesel. Pull up wherever you are — the verge on Kineton Lane, a lay-by, a side street — then leave it there. The drain and flush still come first, and they deal with it: when a car is pulled over early, permanent damage is very unusual.
Petrol in a diesel stories Illshaw Heath motorists hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed by topping up — you're left with a bigger tank, still the same mix. That guidance presumes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: a current diesel copes with a bit of petrol. Rather, the reverse. Lubrication counts more on newer diesels, not less, since their fuel passes through smaller parts at higher pressure.
One myth that catches drivers off guard: if it starts and drives, it must be unharmed. The driver of a petrol engine fed diesel normally has no choice but to stop, since it will not run, and the harm stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually does; meanwhile your pump grinds. Being able to run isn't proof of being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct fault. What petrol has weakened stays thinned, and that petrol stays inside your tank anyway.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol lies in your filter and lines, waiting to go straight back through your pump on your next start. It is also truly risky to drain petrol into a can by the roadside.
Why petrol in a diesel occurs at all
Carelessness is seldom the cause, and no one means to do it. The petrol nozzle is the smaller 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.
Routine and your car falling out of step is when it takes place. Courtesy car, hire car, or a vehicle that is brand new. Two cars on one driveway, one petrol, one diesel. Your usual forecourt, its pumps now in a different order. Rushing for a train at The Lakes and filling up en route. Years of petrol motors behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that's when. The 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 Illshaw Heath: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the pump's label; the colour is only a hint.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of cars print the fuel type there.
- One of each in the house? Label your key to your diesel — a bright fob, a sticker — because intending to remember is not enough.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new vehicle, say "diesel" aloud. Daft, yes, but 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.
- A misfuel inhibitor helps, up to a point. Some diesels have a filler designed to block a petrol nozzle, and add-on devices exist for cars without one. They are a backstop, not a reason to stop reading the petrol pump.
- Less petrol means a weaker mix, and so stop as soon as you realise — while remembering that the next stage is unchanged. It's still not to crank it.
Already put petrol in a diesel in Illshaw Heath?
Then the order of things is brief. Leave it unstarted, with your ignition off too. Still on the forecourt, at Murco or anywhere else? Ask the attendants to help you roll it away from the pump. Call 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and whether it has run.
If it was AdBlue rather than petrol, say so. That's a different fault — corrosion and deposits instead of lost protection — and it has its own page for Illshaw Heath.
What makes one Illshaw Heath petrol in a diesel task cost more than the next
Four different jobs sit behind the four scenarios above — which is why there's no honest single price. What moves the cost is mostly which of them you are in. After that it is the proportion — how much petrol got in against how much that tank holds — and then where your car is and whether a technician can reach it safely.
That is why our engineers ask three queries before pricing instead of after: what was put in, how much, and whether it's run. With the replies, you get a straight figure rather than a range.
About Illshaw Heath, for a moment
Illshaw Heath is a small village in the West Midlands, situated near the River Blythe and surrounded by other local communities such as Warings Green and Salter Street. Illshaw Heath sits at an elevation of 142 metres, with semi-detached housing being the predominant type of accommodation. Illshaw Heath is located close to Birmingham, approximately 8.8 miles away, and is part of the wider West Midlands region. Illshaw Heath has a population of around 512 people, according to recent estimates.
Fuel drain cover across West Midlands, Illshaw Heath included
Warings Green, Salter Street and Cheswick Green are among the spots near Illshaw Heath that the same teams work, answering petrol in diesel jobs across Illshaw Heath's B postcode area. The car does not need to move to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump around Illshaw Heath, right now?
In that case, you could not be in a better spot. Phone, and keep it switched off.