How Worried Should You Be? Petrol in a Diesel Car in Fernhill
Unstarted? Then less worried than you likely are. Everyone around Fernhill begins with "have I ruined it?", and the fair answer is usually no: petrol resting in that tank of a diesel remains harmless till priming, cranking or driving pulls it into your fuel system. Leave your engine off and ring Petrol in Diesel — that keeps it that way. What petrol actually does to a diesel, how to judge how far it's gone, and how to keep it from happening a second time: that's the remainder of this page.
Petrol in a diesel: what does it do to the motor?
Two tasks fall to diesel on its route round a motor. It burns, and before it ignites it lubricates. Designed to extremely fine tolerances, the fuel injectors and the pump depend on the diesel flowing through them to keep their surfaces from wearing against one another.
The second job petrol doesn't do at all, and the first it does poorly. The clattering 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 protection the fuel system hinges on, and any pump running on such a blend is wearing itself.
Put those together and the shape of the trouble is plain. Not contact but movement is what causes the harm. Petrol in a tank is a fuel problem. Whatever a worn pump sheds goes on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has worked on the petrol is where a mechanical issue starts.
Fernhill, petrol in a diesel: four cases, from mild to serious
Filled up, and never started: no case is better. Only the tank has petrol in it, so the job is clearing your tank and purging your system where the car stands. This situation can only truly take place at a forecourt: anywhere else, the car got there by being driven.
A brief spell of running, or merely the ignition on. Your system has been bled, and so petrol has left that tank and reached your filter and the lines. That is normally still a simple job — a drain, a flush, and the filter seen to.
Some miles driven, and your pump has spent every one of them labouring on weakened fuel. Distance is only half of that; how hard it was driven matters just as much. Either way the work includes the tank, the lines, the fuel filter and clean fuel through the entire circuit. A school run to the local primary school is one matter. Very different once more: a trip to Glasgow, under 5 miles away, or some miles on the M74, under 3 miles from Fernhill, where the motor kept labouring hard.
Rattling, a ragged idle, smoke, a throttle gone soft: driven until it complained. What you are hearing is your engine signalling fuel that no longer behaves like diesel. Pull up wherever you are — the verge on Neilvaig Drive, a lay-by, a side street — and leave the car there. Lasting damage is very unusual if a car is stopped early, and the fuel drain and flush that still go first take care of it.
Fernhill drivers and the petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing is removed by topping up — you are left with a fuller tank, still the same mixture. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice presumes.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. Finer parts and higher pressure are the way a current diesel runs its fuel, and that makes the protection count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no harm done." Any petrol engine fed diesel usually will not run, and so the motorist stops and the damage stops with them. A diesel fed petrol usually starts, ticks over and drives away as if nothing has happened, while your pump grinds. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It's an old workaround for a separate problem. It doesn't put back what petrol has weakened, and that petrol is still in your tank later.
"Drain it yourself and you're sorted" — a myth, because after it's been running some petrol lies in the fuel filter and lines, ready to go straight back through the pump on the next start. On top of that, petrol drained into a can by the road is truly risky.
Petrol in a diesel: how does it take place?
Nobody does it on purpose, and it's rarely carelessness. One way only, since of the nozzles: the slimmer petrol one slips inside a diesel filler with almost no resistance, while the diesel one mostly will not fit a petrol motor. That is how the forecourt makes it easy.
The moment routine stops matching the vehicle is the moment it happens. A new vehicle, a hire car or a courtesy car. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. A hurried fill en route to Burnside with a train to catch. A new-to-you diesel Volkswagen Passat, its first fuelling, and a motorist accustomed to petrol: precisely when it happens. With rain, a call arriving, or children to deal with, your hand just does what it always has.
Preventing petrol in a diesel next time you fill up in Fernhill
- The label is what counts, and so read the petrol pump instead of the colour: in the UK unleaded handles are usually green and diesel black, yet not on every forecourt.
- Inspect your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in a motor you don't know.
- Good intentions count for less than a sticker or a fob in a vivid colour on the diesel's key if a home has one of each. So label it.
- Before the nozzle leaves the pump the first time you fuel a hired or new motor, say "diesel" aloud. Silly, perhaps, yet it works.
- Whilst you're thinking about something else, this is an easy mistake to make — so put your phone away.
- A misfuel inhibitor helps, up to a point. Some diesels come with a filler designed to reject a petrol nozzle, and add-on devices exist for vehicles without one. They are a backstop, not a reason to stop reading the petrol pump.
- Less petrol means a weaker mixture, so stop as soon as you notice — though remembering that your next step is unchanged. It is still not to fire it up.
Already put petrol in a diesel in Fernhill?
Then, there is only a short order of things. Leave it unstarted, with your ignition switched off too. Yet at the forecourt, at Esso or anywhere else? Ask the staff to help you roll the vehicle clear of the pump. Then ring 0333 366 0103 and tell us what got in, about how much, and if it has run.
Say so if it was AdBlue instead of petrol: it's a separate fault, with its own page for Fernhill, because AdBlue brings corrosion and deposits instead of lost protection.
What makes one Fernhill petrol in a diesel task cost more than the next
The four situations above are four separate tasks, so no single quote for this would be fair. The situation itself does most of the work of moving your cost. Where the vehicle is matters too, and whether a technician can safely reach it, after the ratio of petrol to what the tank takes.
Three questions come first, before quoting, instead of after — what got in, how much, has it run — and that is the reason. Given those answers, there is a straight figure rather than a range.
About Fernhill itself
Fernhill is a village situated on the riverside in South Lanarkshire, with a relatively low elevation of 96 metres. Fernhill lies close to Glasgow, Scotland's largest city, and is surrounded by nearby places such as Cathkin, High Burnside, and Springhall. Fernhill has a population of approximately 2690 residents, who predominantly live in flat-type housing. Fernhill is located a significant distance from London, at around 340.7 miles away.
Fuel drain cover across South Lanarkshire, Fernhill included
Our teams answering petrol in diesel calls in Fernhill, in the G postcode area, equally work the locations around it, Cathkin, High Burnside and Springhall among them. The car doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Fernhill and still at the pump?
Then, you couldn't be in a better spot. Ring, and keep it switched off.