Should You Worry? Petrol in a Diesel Car in Wemyss Bay
Provided it hasn't been started, you can worry less than you likely are. Until your ignition primes your pump, your starter cranks, or your vehicle is driven, petrol in a diesel tank simply rests there and does nothing. Which means the truthful reply to the first Wemyss Bay query — "have I wrecked it?" — normally no. Keep it that way: leave the engine off and ring Petrol in Diesel. The remainder of this page covers what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
Inside the motor: what petrol in a diesel really does
On its way through a motor, diesel does two jobs. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure pump and the injectors from wearing against one another is the diesel passing through them — they're built to very fine gaps.
Petrol does the first task poorly and the second not at all. A pump running on a petrol blend is wearing itself out, since petrol is thinner than diesel and strips out the lubrication the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that's where the clattering starts.
Put those together and the shape of the trouble is clear. Not contact but circulation is what causes the harm. All a tank with petrol in it amounts to is a fuel problem. Whatever a worn pump sheds goes on, borne by the fuel, into the fuel injectors downstream, which is why a pump that has worked on that petrol is where a mechanical fault starts.
Petrol in a diesel in Wemyss Bay: how bad is it? Four situations
The best case there is: filled up, never started. That petrol is inside the tank and just the tank, and the job is a drain and a flush where your car sits. This is the one scenario that can only truly take place at a forecourt, because anywhere else the car has been driven to get there.
The ignition turned on, or a short start. The system has been bled, so petrol has left that tank and reached the fuel filter and the fuel lines. Usually nothing more than clearing, purging and seeing to your filter, so still straightforward.
Those few miles on the road were your pump working on fuel thinned by petrol throughout. Distance is only half of it; how hard it was driven counts just as much. Either way the work includes the tank, the lines, the fuel filter and fresh fuel through the entire system. On the school run to the local primary school, the miles is short. Driving as far as Glasgow, under 50 miles away, makes a very different task — as does any mileage on the M8, under 15 miles from Wemyss Bay, with the engine labouring hard the whole time.
It protested, and only then stopped: smoke, knocking, a throttle gone soft, an idle gone uneven. What you are hearing is the motor signalling fuel that no longer behaves like diesel. Pull up wherever you are — the verge on Ardgowan Road, a lay-by, a side street — and leave the vehicle where it is. A vehicle stopped early very seldom has permanent damage, because the drain and the flush-through, which still go first, deal with it.
Wemyss Bay motorists and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Nothing is removed by topping up — you are left with a bigger tank, still the same mix. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
"Newer diesels can handle a little petrol" — a myth, and nearer the reverse. A newer diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication count more, not less.
The myth that catches motorists out: if it starts and drives, it must be unharmed. Feed diesel to a petrol engine and it usually will not run, so the motorist stops — and the damage stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually will; meanwhile your pump grinds. Running does not mean fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a distinct fault. That petrol is still inside your tank after that, and what it has diluted is not put back.
The next start draws petrol back round your pump out of the lines and your filter, where some of it ends up once your engine has been run. That is why a DIY tank drain doesn't leave you sorted — a myth. It's also truly dangerous to drain petrol into a can at the roadside.
How petrol ends up: petrol in a diesel
It is rarely carelessness, and nobody does it on purpose. The forecourt makes it easy: the petrol nozzle is the slimmer of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol car at all. So the slip runs one way.
Habit and the car falling out of step is how it takes place. Any motor that's new to you — hired, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. The pumps in a different order on a well-known forecourt. A train to catch, and a rushed fill en route to the nearest station. A new-to-you diesel Volkswagen Golf, its first fuelling, and a driver accustomed to petrol: precisely when it happens. With rain, a call arriving, or children to deal with, the hand simply does what it always has.
Wemyss Bay people: how to avoid petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what counts.
- Check your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you do not know.
- Mark your key. In a household with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember.
- It seems daft 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.
- While you're thinking about something else, this is an easy mistake to make — so put your phone away.
- Some diesels have a filler designed to block 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 reading the pump.
- As soon as you realise, stop: less petrol in that tank means a thinner blend. What to do next does not change, though — still don't crank it.
Wemyss Bay: already put petrol in a diesel?
Then the order of things is short. Do not crank it, and don't switch the ignition on. Yet at the forecourt, at Gulf or anywhere else? Ask the attendants to help you roll the car clear of the petrol pump. Next, 0333 366 0103. We'll ask what got in, about how much, and if it's been run.
Say so if it was AdBlue instead of petrol: it's a different issue, with its own page for Wemyss Bay, because AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel task around Wemyss Bay costs more than another. Why?
An honest single price doesn't exist here: four scenarios, four separate tasks. Chiefly, the cost shifts with which situation you are in. Where the vehicle is matters too, and whether a technician can safely get to it, after the share of petrol to what your tank takes.
Before any quote, not after, we ask three questions: the fuel that was put in, the volume, and whether it has run. That is why. A range becomes a straight figure when the replies are in.
About Wemyss Bay, briefly
Wemyss Bay is a coastal village in Inverclyde, situated on the Firth of Clyde, with a mix of detached housing and scenic views. Wemyss Bay sits at an elevation of 35 metres, looking out across the water to the surrounding hills. Wemyss Bay is located near several other communities, including Inverkip, Upper Skelmorlie, and Skelmorlie, and is approximately 25 miles from Glasgow.
Across Inverclyde and in Wemyss Bay: fuel drain cover
Petrol in diesel call-outs around Wemyss Bay — part of the PA postcode area — go to vans that likewise cover the locations round it, Inverkip, Upper Skelmorlie and Skelmorlie included. The car doesn't need to move to us: we drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Still at the pump around Wemyss Bay?
Then you're in the best spot there can be. Keep the vehicle switched off, then ring.