Galston: Petrol in a Diesel Car? How Worried to Be
Probably less than you already are — provided nobody has started the vehicle. Petrol sitting in a diesel tank does nothing to your engine until something draws it through the system — your ignition priming the pump, your starter, or the drive itself. So the fair answer to the first query anyone around Galston asks, "have I ruined it?", is generally no. To keep the car like that, call Petrol in Diesel then leave the engine alone. Further down, you will find what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you again.
The motor and petrol in a diesel: what goes on
On its way through an engine, diesel does two tasks. Lubricating comes before burning; it does both. Made to very fine clearances, the fuel injectors and your pump depend on your diesel flowing through them to stop their surfaces wearing against one another.
Of these two jobs, petrol handles the first poorly and the second not at all. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump on the mixture to wear itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
The shape of the issue is clear once you put those together. Contact does not do the harm — circulation does. Any tank with petrol in it is a fuel problem. The start of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors beyond it.
Galston, petrol in a diesel: four situations, from mild to major
The best case there is: filled up, not once started. Being on a forecourt is what makes this the case: elsewhere, your car has been driven there to begin with. With that petrol held in that tank alone, it's cleared and flushed on the spot, and nothing more is needed.
A moment's running, or merely the ignition on. The fuel system has been bled, and so petrol has left your tank and got to the filter and the fuel lines. That is generally still a straightforward job — a drain, a flush, and the filter dealt with.
Those few miles driven meant the pump working on fuel thinned by petrol the whole way. Distance is only half of it; how hard it was driven counts equally. Either way this work runs to the tank, the lines, your filter and clean fuel through the entire system. Short trips, like the school run to the local primary school, are one thing. Very different a second time: a trip to Glasgow, under 25 miles away, or some mileage on the M77, under 5 miles from Galston, where your engine kept running hard.
Driven on until it complained — knocking, smoke, a lumpy idle, a dead throttle. The fuel isn't acting like diesel any more, and the engine is telling you. Pull up wherever you are — the verge on Bridge Street, a lay-by, a side street — then leave the car where it is. A car pulled over soon very seldom has permanent damage, as the drain and the flush, which still come first, deal with it.
Galston motorists and the petrol in a diesel myths they hear
False: topping up to full with diesel makes it fine. It doesn't. A fuller tank of the same mixture is all you get, because topping up removes nothing. A diesel fuel system does not accept petrol by percentage in the way that guidance assumes.
Not so: a modern diesel copes with a bit of petrol. Rather, the reverse. At higher pressure, through finer components: that's how a current diesel handles its fuel, so the lubrication counts for more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more drivers than any other. A petrol engine fed diesel generally won't run, and so the motorist stops and the damage stops with them. Whilst the pump grinds, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Running doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate problem. None of what petrol weakened gets put back by it — and afterwards, your tank still contains that petrol.
"Drain it yourself and you are sorted" — a myth, because after it has been running some petrol sits in the filter and lines, waiting to go straight back through your pump on your next start. Besides, petrol drained into a can by the road is truly dangerous.
Petrol in a diesel: how does it take place?
It is rarely carelessness, and nobody does it on purpose. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it simple, and the error runs one way.
The moment routine stops matching the vehicle is the moment it happens. Courtesy car, hire car, or a motor that is brand new. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Filling up in a hurry en route to Kilmarnock, with a train to catch. Years of petrol vehicles behind you, a diesel Volkswagen Passat in front of you on the forecourt for its first tank — that's when. With rain, a call arriving, or children to deal with, your hand simply does what it has always done.
Next time you fill up around Galston: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- In a vehicle you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of cars state the fuel there.
- Good intentions do less than a sticker or a fob in a vivid colour on the diesel's key when a household has one of each. So label it.
- "Diesel", out loud, before you lift the nozzle — every time a new or hired car gets its first tank. It seems daft. It works.
- Mistakes like this are easy to make whilst your mind is on something else, and so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to block a petrol nozzle, and aftermarket devices exist for the rest. Treat it as a safety net, then keep checking the pump.
- Less petrol means a weaker blend, so stop as soon as you realise — though remembering that your next stage is unchanged. It's still not to fire it up.
Put petrol in a diesel in Galston already?
Then the order of things is brief. Starting it is out, and so is switching on your ignition. If you are still at the forecourt — the nearest petrol station or anywhere else — ask the staff to help you push the car clear of the petrol pump. Next, 0333 366 0103. We will ask what was put in, roughly how much, and if it has been run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different problem — Galston has a page all for it.
One petrol in a diesel task around Galston costs more than another. Why?
Four different jobs sit behind the four scenarios above — which is why there's no honest single price. Which of them you are in is chiefly what moves the cost. Where the car is counts too, and whether our van can safely get to it, after the share of petrol to what the tank holds.
That's why our technicians ask three questions before quoting rather than after: what went in, how much, and if it has run. The answers change a range into a straight figure.
About Galston and its setting
Galston is a town situated on the banks of the River Irvine in East Ayrshire, with a mix of semi-detached housing and other residential properties. Galston has a population of around 4662 people and is located near several smaller communities, including Sornhill and Greenholm. Galston sits at an elevation of 52 metres above sea level, approximately 19 miles from Glasgow and 332 miles from London. Galston is part of the wider Glasgow commuter belt, with many residents travelling to the city for work and leisure.
Across East Ayrshire and in Galston: fuel drain cover
Petrol in diesel call-outs around Galston — part of the KA postcode area — go to teams that likewise cover the places around it, Sornhill, Gilfoot and Greenholm included. Our technicians drain wherever the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
Still at the pump around Galston?
No position is better: that is where you now are. Keep it off. Call.