Should You Worry? Petrol in a Diesel Car in Colehill
Unstarted? Then less worried than you likely are. Till your ignition primes the pump, your starter turns, or your car is driven, petrol in a diesel tank simply sits there and does no harm. Which means the truthful reply to the first Colehill query — "have I wrecked it?" — normally no. Keep it like that: leave your engine off then ring Petrol in Diesel. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and ways to make sure you don't repeat it.
Petrol in a diesel: what does it do to the motor?
Passing through an engine, diesel is doing two jobs at the same time. It protects to begin with, and after that does it burn. The high-pressure pump and the injectors are designed to extremely fine gaps, and the diesel passing through them is what stops those surfaces from wearing against one another.
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 on the mixture wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
The shape of the issue is clear once you put those together. Not contact but movement is what causes the damage. Where the petrol is only inside that tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds travels on, borne by the fuel, into the injectors downstream, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Colehill, petrol in a diesel: four cases, from mild to major
Filled up, and never started: no case is better. Only that tank has petrol in it, and so the job is draining your tank and cleaning your system where the car stands. This situation can only truly happen at a forecourt: anywhere else, your car got there by being driven.
Ignition on, or started for a moment. Petrol has left the tank and got to the filter and the lines, because the fuel system has been primed. Drain, flush, deal with the fuel filter: still normally simple.
Those few miles on the road were your pump working on fuel weakened by petrol throughout. Tank, lines, filter, then clean fuel put through the entire circuit: that's this work, and the way your car was driven matters as much as the miles. Short trips, such as the school run to Colehill First School, are one matter. Driving as far as Salisbury, under 25 miles away, makes a very different job — as does any distance on the M27, under 25 miles from Colehill, with your engine running hard all the way.
Driven on until it complained — clattering, smoke, an uneven idle, a dead throttle. That's your engine telling you its fuel has stopped behaving like diesel. Stop where you are — on the verge on Vineries Close, at the kerb, down a side road — and don't move it. A vehicle pulled over soon very rarely has lasting damage, because the fuel drain and the flush-through, which still come first, deal with it.
Stories Colehill motorists hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing comes out when you top up — that tank just carries more of the same mixture. A diesel fuel system does not tolerate petrol by percentage in the way that advice presumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. A modern diesel sends its fuel through finer parts at higher pressure, which makes the protection count more, not less.
This is the one that catches people. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol engine and it generally won't run, so the driver stops — 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 does; meanwhile the pump wears. Fine and running are not the same at all.
Myth: "Add some two-stroke oil and drive the car home." It is an old fix for a separate issue. That petrol is still inside the tank afterwards, and what it has weakened isn't put back.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol lies in the fuel filter and lines, ready to go right back through the pump at the next start. On top of that, petrol cleared into a can by the road is genuinely dangerous.
Why petrol in a diesel takes place so easily
It's seldom carelessness, and nobody does it on purpose. A diesel nozzle generally will not go into a petrol car, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and only in that direction.
Habit and your car falling out of step is when it happens. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the drive of the same household. A familiar forecourt with the pumps in a different order. Fuelling up in a hurry on the way to Parkstone (Dorset), with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it occurs. With rain, a call coming in, or children to deal with, the hand just does what it always has.
Colehill drivers: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is only a hint.
- In a motor you do not know, look inside the flap over the filler or at the cap before the first fill: plenty of vehicles print the fuel type there.
- Mark the key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- Before the nozzle comes off the pump the first time you fuel a hired or new car, say "diesel" aloud. Silly, perhaps, yet it works.
- Tuck the phone away. This is an easy mistake to make while you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler built to refuse a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a safety net, then keep checking the pump.
- Stop the moment you realise. Less petrol in that tank makes a weaker mix. It does not change what to do next, which is still not to crank it.
Already put petrol in a diesel around Colehill?
The order of things is brief, then. Starting it is out, and so is turning on the ignition. Ask the staff to help you push it away from the pump if you are still at the forecourt, whether that is BP or anywhere else. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it has been run.
If it was AdBlue and not petrol, say so. That is a separate fault — corrosion and deposits instead of lost protection — and it has its own page for Colehill.
What makes one Colehill petrol in a diesel task cost more than the next
The four situations above are four different jobs, so no single quote for this would be fair. Mostly, your cost moves with which situation you're in. The ratio counts next, meaning how much of the tank is petrol, and then the location of the vehicle and whether getting to it is safe for a technician.
Ahead of any quote, not after, we ask three queries: your fuel that got in, its amount, and whether it's run. That is why. A range turns into a straight figure once the answers are in.
About Colehill
Colehill is a suburban area in Dorset, situated inland at an elevation of 51 metres, and is characterized by its predominantly detached housing stock. Colehill lies near the villages of Leigh and Rowlands, and is also close to Merry Field Hill. Colehill is located approximately 19.7 miles from Salisbury and 93.2 miles from London, making it a relatively rural suburb. Colehill has a population of around 936 residents.
Colehill and Dorset: where our fuel drain cover runs
The teams answering petrol in diesel calls around Colehill, in the BH postcode area, also work the places near it, Leigh, Merry Field Hill and Rowlands among them. The car does not need to come to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Colehill: still at the pump?
Then you are in the best place there is. Keep the vehicle switched off, then ring.