Wilnecote: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — as long as nobody has started the vehicle. Petrol resting in a diesel tank does nothing to your motor till something draws it through the system — your ignition priming your pump, your starter, or the drive itself. So the honest answer to the first question anyone in Wilnecote asks, "have I ruined it?", is normally no. Petrol in Diesel is who to ring, with your motor kept off, and so it remains that way. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and ways to make sure you don't do it again.
What petrol in a diesel does to the engine
On its way through a motor, diesel has two jobs. Before it ignites, it lubricates — then it combusts. Very fine clearances go into your injectors and the high-pressure pump, and just your diesel running through stops those surfaces grinding together.
Of those two tasks, petrol handles the first badly and the second never. The knocking comes from petrol being made not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection your system hinges on, and any pump working on that mixture is wearing itself.
Combined, those leave the shape of the trouble plain. It is movement that does the harm, not contact. Where that petrol is only inside your tank, it's a problem of fuel, nothing more. Once your pump has been running on that petrol, a mechanical issue has begun: whatever is shed by a pump that's wearing down travels downstream to the fuel injectors with the fuel.
How bad is petrol in a diesel? Four scenarios we see in Wilnecote
The best case there can be: filled up, never started. That petrol is in that tank and only your tank, and the task is a drain and a flush where the car sits. This is the one situation that can only really happen on a forecourt, as anywhere else the car has been driven to get there.
Started for a second, or only your ignition on. Once primed, the fuel system has pulled petrol out of that tank up to the filter and the fuel lines. Drain, flush, deal with the fuel filter: still usually simple.
Some miles driven, and your pump has spent every one of them labouring on diluted fuel. How hard your car was driven counts as much as how far, and the work covers your tank, the fuel lines, the filter and fresh fuel through the whole system. Driving the children to Wilnecote Junior Academy is one kind of trip. Driving as far as Lichfield, under 10 miles away, makes a very different job — as does any distance on the M42, under a mile from Wilnecote, with your engine running hard all the way.
Driven till it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer acting like diesel. Stop wherever you are — the verge on Stonydelph Lane, a lay-by, a side street — and leave the car there. A vehicle stopped soon very seldom has lasting damage, because the fuel drain and the flush, which still go first, deal with it.
What Wilnecote drivers get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed when you top up — your tank just holds more of the same mixture. The idea behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." More precise parts and higher pressure are the way a newer diesel runs its fuel, and that makes the lubrication count more, not less.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." The motorist of a petrol motor fed diesel normally has no choice but to stop, since it will not run, and the harm stops there. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile your pump grinds. Running isn't the same as fine.
Not so: a two-stroke additive lets you to drive home. It was an old workaround, meant for another fault. That petrol is still in that tank after that, and what it has weakened is not put back.
The next start draws petrol back round the pump out of your lines and the filter, where some of that ends up after the motor has been run. That is why draining your tank yourself doesn't leave you sorted — a myth. It is also truly dangerous to drain petrol into a can by the kerbside.
How petrol ends up: petrol in a diesel
Nobody does it on purpose, and it is seldom carelessness. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly will not go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
The moment routine stops matching the vehicle is the moment it takes place. Courtesy car, hire car, or a car that's brand new. Two vehicles on one driveway, one petrol, one diesel. The pumps in a different order on a familiar forecourt. Fuelling up in a hurry en route to the nearest station, 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. Throw in a back seat full of kids, a phone call or rain, and the hand wins.
Next time you fill up in Wilnecote: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on every forecourt. The label is what matters.
- 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 state the fuel type there.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of intending to remember, for a household with one of each.
- It seems daft and it works: on the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- While you are thinking about something else, this is an easy mistake to make — so put your phone away.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that will not accept a petrol nozzle. Useful — but a safety net at best, never a reason to stop checking the label.
- The moment you realise, stop: less petrol in that tank makes a thinner blend. What to do next does not change, though — still don't fire it up.
Put petrol in a diesel around Wilnecote already?
The order of things is short, then. Don't fire it up, and don't switch your ignition on. If you're still on the forecourt — Morrisons or anywhere else — ask the attendants to help you roll the vehicle clear of the pump. Phone 0333 366 0103 next, with three answers — your fuel, the approximate amount, and if it has run.
Say so if it was AdBlue instead of petrol: it's a different problem, with its own page for Wilnecote, since AdBlue brings corrosion and deposits rather than lost protection.
Wilnecote petrol in a diesel tasks: why one costs more than another
Four separate tasks lie behind the four scenarios above — which is why there's no honest single quote. The scenario itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a proportion of what that tank holds, then the place the car is in and whether a technician can get to it safely.
What went in, how much, and if it's run — three questions our technicians ask before pricing, not after, for exactly that reason. Those replies are what turn a range into one firm number.
About Wilnecote itself
Wilnecote is a suburban area in Staffordshire, situated on the riverside at an elevation of 86 metres, with semi-detached housing being the predominant type of accommodation. Wilnecote lies near the cities of Lichfield and Tamworth, and is close to nearby places such as Stonydelph, Hockley, and Two Gates. Wilnecote has a population of approximately 4887 residents, and is located about 100 miles northwest of London. Wilnecote forms part of the wider West Midlands region, with its riverside setting contributing to its character.
Wilnecote and Staffordshire: where our fuel drain cover runs
Wilnecote waits in the B postcode area, and the teams that answer petrol in diesel call-outs there work the places around it as well — Stonydelph, Hockley and Two Gates among them. We drain wherever your vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Wilnecote: still at the pump?
Then you are in the best spot there can be. Leave it switched off, and ring.