How Worried Should You Be? Petrol in a Diesel Car in Poolway
Unstarted? Then less anxious than you probably feel. Everyone in Poolway starts with "have I wrecked it?", and the fair answer is usually no: petrol left inside that tank of a diesel stays harmless till priming, cranking or driving pulls it into the fuel system. Leave the engine off and call Petrol in Diesel — that keeps it that way. The rest of this page covers 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 again.
Inside the motor: what petrol in a diesel really does
On its way through an engine, diesel does two jobs. It protects first, and after that does it burn. Made to very fine gaps, the injectors and the pump rely on your diesel flowing through them to keep their surfaces from wearing against one another.
Badly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump running on the blend to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the clattering.
Combined, those leave the shape of the issue plain. Contact doesn't do the harm — circulation does. Petrol in a tank is a fuel issue. Whatever a worn pump sheds goes on, carried by your fuel, into the fuel injectors further along, which is why a pump that has been working on the petrol is where a mechanical fault begins.
Petrol in a diesel in Poolway: how serious is it? Four situations
Fuelled, and not started: no case is better. Only the tank has petrol in it, so the job is emptying the tank and purging your system where the car sits. This scenario can only really occur on a forecourt: anywhere else, the car got there by being driven.
The ignition turned on, or a brief start. Petrol has come out of your tank and reached your filter and the fuel lines, because the fuel system has been primed. Still usually simple: drain, flush, and the filter sorted.
Your pump has spent a few miles on weakened fuel — that is what driving it meant. Distance is only half of it; how hard it was driven counts equally. Either way the work includes your tank, your lines, the fuel filter and clean fuel through the entire circuit. On the school run to St John's C of E Academy, the miles is short. Very different again: a trip to Gloucester, under 25 miles away, or any distance on the M50, under 10 miles from Poolway, where your engine kept running hard.
Knocking, a ragged idle, smoke, a throttle gone soft: driven until it complained. That's your motor telling you its fuel has stopped behaving like diesel. Pull up on the spot — on the verge on Wynols Hill Lane, at the kerb, down a side road — and do not move it again. What comes first is still the fuel drain and flush-through, and that takes care of it, with lasting damage very unusual if a vehicle is pulled over soon.
Stories Poolway drivers hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. That advice assumes a diesel fuel system handles petrol by percentage. It does not.
If anything, the reverse is true. Myth: "A modern diesel can cope with a bit of petrol." At higher pressure, through more precise parts: that's how a current diesel moves its fuel, and so the lubrication matters more, not less.
"It starts, it drives, so no harm done" — the myth that trips up most motorists than any other. Diesel in a petrol motor normally leaves a motor that won't run: the motorist stops, and so does the harm. Whilst the pump wears, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Running does not mean fine.
An old workaround for a separate fault is behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol thinned is put back by it — and afterwards, your tank still contains the petrol.
Myth: "Drain the tank yourself and you're sorted." Once the engine has been run, some of that petrol is no longer in that tank: it is in the fuel filter and your lines, and it goes right back through your pump on the next start. On top of that, petrol emptied into a can by the road is truly hazardous.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol motor at all. The forecourt makes it easy, and the error runs one way.
It takes place when habit and your car stop matching. 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. A well-known forecourt with the pumps in a different order. Filling up in a rush on the way to Lydney, with a train to catch. Precisely the moment it occurs: after years of driving petrol, someone fills a diesel Renault Megane for the first time. With rain, a call coming in, or children to deal with, the hand simply does what it always has.
Poolway drivers: how to avoid petrol in a diesel next time
- A green handle for unleaded and black for diesel is usual in the UK — but not on every forecourt. Trust the label on the petrol pump, not the colour.
- The first fill in a new motor is the time to check your filler flap — inside it, or on the cap, many motors state which fuel to use.
- One of each in the home? Label the key to the diesel — a coloured fob, a sticker — because intending to remember isn't 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 petrol pump. It sounds silly and it works.
- Mistakes like this are straightforward to make whilst 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 refuse a petrol nozzle, and add-on devices are available for motors without one. They are a safety net, not a reason to stop reading the petrol pump.
- Noticing it halfway? Stop there and then. A thinner blend results from less petrol in that tank, but the next step stays the same: don't crank it.
Put petrol in a diesel in Poolway already?
In that case, there's only a short order of things. Never start it, and don't turn the ignition on. Yet at the forecourt, at Texaco or anywhere else? Ask the attendants to help you roll it away from the pump. Phone 0333 366 0103 next, with three answers — your fuel, the rough volume, and whether it has run.
Say so if it was AdBlue instead of petrol: it is a different issue, with its own page for Poolway, because AdBlue brings corrosion and deposits rather than lost protection.
What makes one Poolway petrol in a diesel job cost more than the next
The four scenarios above are four separate jobs, so no single price for this would be fair. Chiefly, the cost moves with which one you're in. Two things come after that: the petrol that got in as a share of what your tank holds, then the place the vehicle is in and whether our van can reach it safely.
Three questions come first, before any quote, rather than after — what went in, how much, has it run — and this is the reason. With those replies, you get a straight figure rather than a range.
About Poolway itself
Poolway is a suburban area in Gloucestershire, situated inland at an elevation of 186 metres, with semi-detached housing being the predominant type of accommodation. Poolway lies near the towns of Coleford and the city of Gloucester, and is also close to smaller settlements like Bakers Hill and High Nash. Poolway is part of the wider South West region of England, and is approximately 108 miles west of London.
Poolway and Gloucestershire: where our fuel drain cover runs
Petrol in diesel calls around Poolway — part of the GL postcode area — go to teams that also cover the spots about it, Coleford, Bakers Hill and High Nash included. Our engineers drain wherever the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
In Poolway and still at the petrol pump?
The best place there is, then — that's where you are. Ring, and leave it turned off.