Should You Worry? Petrol in a Diesel Car in Cofton Common
Likely less than you already are — as long as no one has started it. Everyone around Cofton Common starts with "have I ruined it?", and the honest answer is normally no: petrol resting in that tank of a diesel remains harmless till priming, cranking or driving pulls it into the fuel system. To leave the vehicle that way, ring Petrol in Diesel and leave the engine switched off. The remainder of this page explains what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you a second time.
The motor and petrol in a diesel: what goes on
Two tasks fall to diesel on its journey round a motor. Before it ignites, it lubricates — and then it burns. Extremely fine clearances are built into the injectors and the high-pressure fuel pump, and only your diesel running through keeps those surfaces from grinding together.
Badly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running on the mixture wearing itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Together, those make the shape of the trouble plain. Not contact but circulation is what does the damage. Where that petrol is only in your tank, it's a problem of fuel, nothing more. Whatever a worn pump sheds travels on, borne by your fuel, into your injectors further along, which is why a pump that has been working on that petrol is where a mechanical issue begins.
Four scenarios our technicians see in Cofton Common: how serious is petrol in a diesel?
The best case there can be: filled up, never started. Being at a forecourt is what makes this the case: elsewhere, the car has been driven there to begin with. With the petrol kept in the tank alone, it is cleared and purged right where it stands, and nothing more is needed.
A brief spell of running, or merely the ignition on. With your system primed, the lines and filter already contain petrol that came from that tank. Normally little more than emptying, flushing and sorting the filter, so still straightforward.
The pump has worked a couple of miles on thinned fuel — that is what driving the vehicle does. The work is the tank, the fuel lines, your filter and fresh fuel through the entire circuit, and how hard your car was driven matters as much as how far. Driving the children to Albert Bradbeer Primary Academy is one sort of trip. Very different a second time: a run to Birmingham, under 10 miles away, or any distance on the M5, under 3 miles from Cofton Common, where the engine never stopped working hard.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. The engine is telling you the fuel is no longer acting like diesel. Stop wherever you are — the verge on Longbridge Lane, a lay-by, a side street — then leave the vehicle where it is. Lasting damage is very uncommon if a vehicle is pulled over soon, and the drain and flush-through that still go first deal with it.
What Cofton Common motorists get told about petrol in a diesel — and the myths in it
Myth: topping up to full with diesel makes it fine. It does not. A bigger tank of the same mix is all it gives, because topping up takes out nothing. That advice assumes a diesel fuel system handles petrol by percentage. It does not.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. At higher pressure, through smaller components: that's how a modern diesel handles its fuel, so the protection counts more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." Feed diesel to a petrol motor and it generally will not run, so the driver stops — and the damage stops with them. Whilst the pump wears, a diesel fed petrol usually starts, ticks over and drives away as if nothing has happened. Being able to run isn't the same as being fine.
An outdated fix for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the car home." It doesn't put back what petrol has weakened, and that petrol is still in your tank later.
The next start sends petrol back round your pump out of your lines and the fuel filter, where some of that sits after the engine has been run. That's why draining the tank yourself doesn't sort it — a myth. Draining petrol into a can by the roadside is also genuinely risky.
How petrol ends up: petrol in a diesel
Nobody does it on purpose, and it is rarely carelessness. One way only, because of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol vehicle. That is how the forecourt makes it straightforward.
Routine and the car getting out of step is when it happens. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the drive of the same household. A forecourt you know, only with its pumps arranged differently. A train to catch, and a rushed fill on the way to Longbridge. A new-to-you diesel Renault Megane, its first fuelling, and a motorist accustomed to petrol: precisely when it occurs. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Avoiding petrol in a diesel next time you fill up in Cofton Common
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on each forecourt. The label is what counts.
- The first fill in a new motor is the time to check the filler flap — on it, or on the cap, plenty of motors state the fuel to use.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key if a house has one of each. So label it.
- It seems silly and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- Tuck the phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels have a filler designed to reject 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.
- Spotting it halfway? Stop at once. A weaker mix results from less petrol in your tank, yet the next step remains the same: do not crank it.
Already put petrol in a diesel around Cofton Common?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. If you're still on the forecourt — BP or anywhere else — ask the attendants to help you push the vehicle clear of the pump. Call 0333 366 0103 next, with three facts — the fuel, the approximate quantity, and whether it's run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a separate issue — Cofton Common has a page all for it.
One petrol in a diesel job in Cofton Common costs more than another. Why?
The four situations above are four separate tasks, so no single quote for this would be honest. What moves your cost is chiefly which of them you're in. Two things come after that: the petrol that was put in as a proportion of what that tank takes, then the place your car is in and whether a technician can reach it safely.
Three questions come first, before quoting, instead of after — what went in, how much, has it run — and that is the reason. Given the replies, you get a straight figure instead of a range.
About Cofton Common itself
Cofton Common is a locality in the West Midlands, situated near the River Rea and close to the cities of Birmingham and Worcester. Cofton Common has a mix of semi-detached housing and local amenities, with nearby places including Longbridge, West Heath, and Turves Green. Cofton Common is located approximately 6.6 miles south-west of Birmingham city centre, at an elevation of around 170 metres. Cofton Common is also around 99.9 miles north-west of London.
Fuel drain cover across West Midlands, Cofton Common included
Longbridge, West Heath and Turves Green are among the places around Cofton Common that the same teams work, answering petrol in diesel calls across Cofton Common's B postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers drain, and the vehicle doesn't need to come to us.
Cofton Common: still at the petrol pump?
The best place there is, then — that is where you are. Leave it switched off, and ring.