Ormiston: Petrol in a Diesel Car? How Worried to Be
If it has not been started, worry less than you probably are. Until your ignition primes the pump, your starter turns, or the vehicle is driven, petrol in a diesel tank simply rests there and does nothing. Which means the truthful reply to that first Ormiston question — "have I ruined it?" — usually no. To leave the vehicle like that, call Petrol in Diesel then leave your engine alone. Further down, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
What petrol in a diesel does to your engine
Diesel has two jobs on its way through a motor. It ignites, and before it burns it lubricates. Built to very fine gaps, the fuel injectors and the pump rely on your diesel moving through them to stop their surfaces wearing against one another.
Of these two tasks, petrol handles the first poorly and the second never. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, leaving a pump on the blend to wear itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the rattling.
Taken together, they show the shape the trouble takes. It is circulation that causes the harm, not contact. A tank with petrol in it is a fuel fault. After the pump has been running on that petrol, a mechanical fault has started: whatever is shed by a pump that is wearing down is carried downstream to the fuel injectors with the fuel.
How bad is petrol in a diesel? Four situations our technicians see around Ormiston
Filled up, never started. The best case there can be. On a forecourt, and genuinely only there, that petrol is still limited to the tank — since everywhere else the vehicle was driven to reach it. The job is emptying and purging on the spot.
Your ignition turned on, or a short start. Once primed, the fuel system has pulled petrol from that tank up to your filter and the fuel lines. That is generally still an easy job — a drain, a flush, and the filter seen to.
A few miles driven, and the pump has spent each of them labouring on diluted fuel. Tank, lines, filter, then clean fuel run through the entire circuit: that's the work, and the way your car was driven matters as much as the mileage. Short trips, such as the school run to the local primary school, are one matter. A run as far as Edinburgh, under 15 miles away, is a very different job. So is any miles on the M8, under 15 miles from Ormiston, where the motor has been running hard throughout.
Knocking, a ragged idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the motor reporting fuel that no longer behaves like diesel. Pull up where you are — on the verge on Main Street, at the kerb, down a side road — and do not move it. Long-term damage is very rare if a vehicle is stopped soon, and the drain and flush that still come first sort it out.
Ormiston motorists and the petrol in a diesel stories they hear
False: topping up to full with diesel makes it fine. It doesn't. Nothing comes out when you top up — your tank simply holds more of the same mixture. The assumption behind the advice — that diesel fuel systems accept petrol by percentage — is wrong.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. Finer components and higher pressure are how a newer diesel runs its fuel, and that makes the protection count more, not less.
The myth that catches people out: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally means a motor that won't run: the driver stops, and so does the damage. While the pump grinds, a diesel fed petrol normally starts, idles and drives away as if nothing has happened. Running is not the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated fix for a different fault. None of what petrol thinned gets put back by it — and afterwards, your tank still contains the petrol.
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's why a DIY tank drain does not sort it — a myth. Clearing petrol into a can at the kerbside is also really hazardous.
How does petrol in a diesel take place?
No one does it on purpose, and it's rarely carelessness. One way only, since of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol car. That is how the forecourt makes it simple.
When habit and your car stop matching, it takes place. Courtesy car, hire car, or a motor that's brand new. One petrol and one diesel on the driveway of the same household. Your usual forecourt, its pumps suddenly in a different order. A hurried fill on the way to Prestonpans with a train to catch. The first fill-up in a diesel Volkswagen Tiguan after years of driving petrol is exactly the moment it takes place. The hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
Ormiston drivers: how to avoid petrol in a diesel next time
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Check the pump's label; the colour is only a hint.
- Inspect the filler flap. Plenty of cars state the fuel inside the flap or on the cap. Look at it on the first fill in any motor you don't know.
- One of each in the house? Mark the key to your diesel — a coloured fob, a sticker — since intending to remember is not enough.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump. It seems silly and it works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- Some diesels come with a filler designed to refuse a petrol nozzle, and devices you can add exist for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the petrol pump.
- Less petrol means a thinner blend, and so stop as soon as you notice — though remembering that the next step is unchanged. It is still not to fire it up.
Already put petrol in a diesel in Ormiston?
In that case, there's just a short order of things. Starting it is out, and so is turning on your ignition. If you're still at the forecourt — Gulf or anywhere else — ask the attendants to help you push the car clear of the petrol pump. Then phone 0333 366 0103 and tell us what got in, roughly how much, and if it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost lubrication, make it a different problem — Ormiston has a page all for it.
What makes one Ormiston petrol in a diesel task cost more than the next
A fair single price does not exist here: four situations, four separate jobs. The situation itself does most of the work of moving your cost. After that it's the share — how much petrol went in against how much your tank takes — and then where the car is and whether a technician can reach it safely.
Three queries come first, before quoting, rather than after — what was put in, how much, has it run — and that is the reason. A range turns into a straight figure once those answers are in.
About Ormiston
Ormiston is a village in East Lothian, situated on the riverside at an elevation of 87 metres, approximately 10 miles from Edinburgh. Ormiston has a mix of housing types, but semi-detached homes are predominant in the area. Ormiston is close to several nearby places, including Elphinstone, South Elphinstone, and North Elphinstone, and is located about 325 miles north of London.
Fuel drain cover across East Lothian, Ormiston included
Our vans answering petrol in diesel jobs in Ormiston, in the EH postcode area, equally work the places near it, Elphinstone, South Elphinstone and North Elphinstone among them. No need to move your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations we drain.
In Ormiston and still at the pump?
Then you are in the best position there can be. Ring, and keep it turned off.