How Worried Should You Be? Petrol in a Diesel Car in Falmer
Far less than you probably are, if it hasn't been started. Everyone in Falmer starts with "have I wrecked it?", and the fair answer is usually no: petrol resting in that tank of a diesel remains harmless until priming, cranking or driving pulls it into your fuel system. Petrol in Diesel is who to ring, with your engine kept off, and so it stays that way. Keep reading for three things: the effect petrol has inside a diesel engine, the signs of how far it has got, and the way to make sure you never do it again.
Inside the engine: what petrol in a diesel does
On its way through an engine, diesel has two tasks. It lubricates to begin with, and only then does it burn. Extremely fine tolerances are built into your injectors and the high-pressure pump, and just your diesel running through stops those surfaces grinding together.
Petrol handles the first job badly and the second not at all. The rattling 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 lubrication your system depends on, and any pump working on such a blend is wearing itself.
The shape of the issue is clear when you put those together. Not contact but circulation is what causes the harm. All a tank with petrol in it amounts to is a fuel fault. Once your pump has been working on that petrol, a mechanical fault has begun: whatever is shed by a pump that is wearing down travels downstream to your injectors with the fuel.
How bad is petrol in a diesel? Four situations our technicians see in Falmer
The best case there is: filled up, not once started. That petrol is in the tank and only your tank, and the task is a drain and a flush where the car stands. This is the one situation that can only really happen at a forecourt, as anywhere else the vehicle has been driven to get there.
Ignition on, or started for a second. Petrol has come out of that tank and reached the filter and the fuel lines, because the system has been bled. Still usually easy: drain, flush, and the filter seen to.
Driven a couple of miles. Now the pump has spent these miles running on weakened fuel. How hard the vehicle was driven counts as much as how far, and this work covers your tank, your lines, the fuel filter and fresh fuel through the entire system. Driving the children to Coldean Primary School is one sort of trip. Very different a second time: a trip to Brighton and Hove, under 5 miles away, or some miles on the M23, under 25 miles from Falmer, where your engine kept working hard.
Rattling, a ragged idle, smoke, a throttle gone soft: driven till it complained. That's your engine telling you its fuel no longer is behaving like diesel. Stop wherever you are — the verge on Park Street, a lay-by, a side street — then leave it there. What comes first is still the drain and flush-through, and that deals with it, with lasting damage very unusual if a car is pulled over soon.
Stories Falmer people hear about petrol in a diesel
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Topping up removes nothing; it gives you a fuller tank of the same mix. A diesel fuel system does not accept petrol by percentage in the way that advice assumes.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the reverse. A newer diesel runs its fuel through more precise components at higher pressure, which makes the protection count more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." The driver of a petrol motor fed diesel usually has no choice but to stop, since it will not run, and the damage stops with them. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, whilst your pump grinds. Running doesn't mean fine.
An outdated fix for a different fault lies behind this one. Myth: "Add some two-stroke oil and drive it home." What petrol has weakened stays weakened, and the petrol stays inside the tank anyway.
Myth: "Drain that tank yourself and you are sorted." After your engine has been run, some of the petrol is no longer in that tank: it is in the fuel filter and the lines, and it goes straight back through the pump at your next start. Besides, petrol drained into a can by the road is truly dangerous.
Petrol in a diesel: how does it take place?
A careless moment is rarely the cause, and nobody means to do it. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it easy, and the mistake runs one way.
When habit and your car stop matching, it happens. A vehicle that's new to you — hired, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. The pumps in a different order on a well-known forecourt. Fuelling up in a rush on the way to the nearest station, with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a driver accustomed to petrol: precisely when it occurs. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel at your next fill-up around Falmer
- 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 just a clue.
- The first fill in a new car is the time to check the filler flap — on it, or on the cap, many vehicles state the fuel to use.
- A coloured fob or a sticker on the diesel's key does more than any amount of intending to remember, in a household with one of each.
- It seems silly and it works: on the 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 simple to make while your mind is on something else, so your phone goes away.
- Some diesels come with a filler designed to reject a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- The moment you realise, stop: less petrol inside your tank makes a weaker blend. What to do next does not change, though — still don't start the vehicle.
Already put petrol in a diesel around Falmer?
Then, there's only a short order of things. Starting it is out, and so is turning on your ignition. Ask the staff to help you roll it clear of the pump if you're still at the forecourt, whether that's Esso or anywhere else. What got in, roughly how much, and whether it's run: tell us that when you ring 0333 366 0103.
Say so if it was AdBlue instead of petrol: it is a separate fault, with its own page for Falmer, since AdBlue brings corrosion and deposits instead of lost protection.
What makes one Falmer petrol in a diesel job cost more than the next
There's no fair single quote for this, since the four situations above are four separate jobs. Which of them you are in is chiefly what shifts your cost. Where your car is counts too, and whether our van can safely get to it, after the ratio of petrol to what that tank takes.
Before any quote, not after, we ask three queries: the fuel that went in, the volume, and whether it's run. That is why. Given the replies, there is a straight figure rather than a range.
About Falmer itself
Falmer is a village in East Sussex, situated approximately 4 miles north of Brighton and Hove, and 44.5 miles south of London. Falmer sits in a relatively low-lying area, with an elevation of around 98 metres, and is surrounded by nearby places such as Stanmer, North Moulsecoomb, and Coldean. Falmer has a population of around 3327 people, and its predominant housing stock consists of semi-detached homes.
Fuel drain cover across East Sussex, Falmer included
Petrol in diesel call-outs in Falmer — part of the BN postcode area — go to vans that also cover the places round it, Stanmer, North Moulsecoomb and Coldean included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our technicians work, and the vehicle doesn't need to come to us.
At the petrol pump in Falmer, right now?
In that case, you couldn't be in a better position. Keep it off. Ring.