Should You Worry? Petrol in a Diesel Car in Camels Head
Provided it hasn't been started, you can worry less than you likely are. Until the ignition primes your pump, your starter turns, or the car is driven, petrol in a diesel tank just waits there and does no harm. Which means the honest reply to that first Camels Head query — "have I ruined it?" — normally no. Keep it like that: leave your engine off and phone Petrol in Diesel. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
Inside the engine: what petrol in a diesel does
Diesel does two jobs on its way through a motor. It protects to begin with, and after that does it burn. Extremely fine tolerances go into your injectors and the high-pressure pump, and just the diesel flowing through stops those surfaces grinding together.
The second job petrol does not do at all, and the first it does badly. The rattling comes from petrol being made not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the lubrication your system rests on, and any pump working on that blend is wearing itself.
Together, those leave the shape of the problem plain. Not contact but movement is what causes the damage. A tank with petrol in it is a fuel issue. The beginning of a mechanical problem is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with the fuel to your injectors beyond it.
Camels Head, petrol in a diesel: four cases, from mild to significant
Filled up, and never started: nothing beats it. Just the tank has petrol in it, so the task is emptying the tank and flushing the fuel system where your car stands. This scenario can only really occur at a forecourt: anywhere else, the car got there by being driven.
A moment's running, or just your ignition on. Once primed, your system has drawn petrol from the tank up to the filter and the fuel lines. Drain, flush, see to your filter: still normally straightforward.
Some miles driven, and your pump has spent every one of them labouring on weakened fuel. The work is that tank, the lines, the filter and fresh fuel through the entire circuit, and how hard the car was driven matters as much as how far. A school run to Weston Mill Community Primary Academy is one matter. A run as far as Plymouth, under 3 miles away, is a very different task. So is any miles on the M5, under 50 miles from Camels Head, where your engine has been labouring hard throughout.
Driven till it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. The motor is telling you the fuel is no longer behaving like diesel. Stop wherever you are — the verge on Saltash Road, a lay-by, a side street — and leave it where it is. Permanent damage is very uncommon when a car is pulled over early, and the fuel drain and flush-through that still come first take care of it.
Myths Camels Head drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It does not. Topping up removes nothing; it gives you a bigger tank of the same mixture. The idea behind the guidance — that diesel fuel systems accept petrol by percentage — is wrong.
If anything, the opposite is true. Myth: "A current diesel can cope with a bit of petrol." Lubrication matters more on current diesels, not less, because their fuel runs through more precise parts at higher pressure.
This is the one that catches people. Myth: "If it starts and drives, there is no damage done." Any petrol motor fed diesel generally will not run, so the motorist stops and the harm stops with them. Whilst the pump wears, a diesel fed petrol usually starts, idles and drives away as though nothing has happened. A running engine does not mean fine.
An old fix for a separate fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." What petrol has diluted stays diluted, and that petrol stays in your tank regardless.
If the motor has been run, part of that petrol sits in the filter and your lines, not that tank — and the next start pulls it straight back through your pump. So the myth "drain the tank yourself and you are sorted" doesn't hold. Also, a can of petrol drained by the kerbside is truly hazardous.
Why petrol in a diesel happens at all
It's rarely carelessness, and no one does it on purpose. A diesel nozzle generally won't fit a petrol car, but the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one error easy, and only in that direction.
It takes place when habit and the vehicle stop matching. Any car that is new to you — hired, on loan as a courtesy car, or brand new. Two motors on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps arranged differently. A hurried fill on the way to Keyham with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. Throw in rain, a phone call or a back seat full of children, and your hand does what it has always done.
Preventing petrol in a diesel next time you fill up in Camels Head
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the petrol pump's label; the colour is just a clue.
- Plenty of motors state the fuel inside the filler flap or on the cap, so check it on your first fill in any vehicle you don't know.
- One of each in the house? Mark the key to the diesel — a bright fob, a sticker — because intending to remember isn't enough.
- It sounds silly and it works: on your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Mistakes like this are straightforward to make while your mind is on something else, and so your phone goes away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler built to reject a petrol nozzle, and add-on devices exist for motors without one. They are a safety net, not a reason to stop reading the pump.
- Less petrol makes a weaker mixture, and so stop as soon as you realise — though remembering that your next stage is unchanged. It's still not to start the vehicle.
Petrol already in a diesel in Camels Head? Begin here
The order of things is brief, then. Leave it unstarted, with the ignition switched off as well. If you are still at the forecourt — Gulf or anywhere else — ask the attendants to help you push the car clear of the pump. Next, 0333 366 0103. We will ask what was put in, about how much, and if it's been run.
Say so if it was AdBlue rather than petrol: it's a separate fault, with its own page for Camels Head, since AdBlue brings corrosion and deposits rather than lost protection.
Why one petrol in a diesel job around Camels Head costs more than another
A fair single price doesn't exist here: four scenarios, four separate tasks. What shifts your cost is mostly which of them you're in. Two things follow that: the petrol that was put in as a share of what that tank holds, then the spot the car is in and whether a technician can reach it safely.
What was put in, how much, and whether it has run — three queries we ask before pricing, not after, for exactly that reason. The replies change a range into a straight figure.
About Camels Head and where it is
Camels Head is a coastal suburban area in Devon, situated near the city of Plymouth and close to the neighbouring areas of Keyham, Weston Mill, and North Prospect. Camels Head has a population of approximately 7924 residents and is characterized by predominantly terraced housing. Camels Head is located at a low elevation of around 9 metres above sea level, reflecting its coastal setting. Camels Head is part of the larger Plymouth urban area, yet maintains its own distinct identity.
Fuel drain cover in Camels Head and across Devon
Keyham, Weston Mill and North Prospect are among the spots near Camels Head that the same vans work, answering petrol in diesel calls across Camels Head's PL postcode area. The vehicle does not need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
In Camels Head and still at the pump?
Then you are in the best position there can be. Leave the vehicle switched off, and ring.