Charleston: Petrol in a Diesel Car? How Worried to Be
If it has not been started, you can worry far less than you probably are. Till your ignition primes your pump, your starter turns, or your vehicle is driven, petrol in a diesel tank simply sits there and does no harm. Which makes the honest reply to the first Charleston query — "have I wrecked it?" — normally no. Keep it like that: leave your motor off then phone Petrol in Diesel. Further down, this page sets out what petrol really does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
Inside your engine: what petrol in a diesel does
Two tasks fall to diesel on its journey through a motor. Before it combusts, it protects — and then it ignites. Made to very fine gaps, the injectors and your pump depend on the diesel flowing through them to keep their surfaces from wearing against one another.
Of these two tasks, petrol manages the first poorly and the second never. Being less viscous than diesel, petrol strips out the protection a fuel system needs, so a pump running on the blend wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you get the knocking.
The shape of the issue is clear once you put those together. Contact does not do the damage — circulation does. A tank with petrol in it is a fuel issue. The beginning of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds travels on with the fuel to the injectors downstream.
Petrol in a diesel in Charleston: how serious is it? Four cases
Filled up, not once started. The best case there is. The petrol is in the tank and just the tank, and the job is a drain and a flush where the vehicle stands. This is the one scenario that can only really happen on a forecourt, as anywhere else the car has been driven to get there.
Ignition on, or started for a second. Petrol has come out of your tank and reached your filter and your lines, because the system has been bled. Still usually simple: drain, flush, and the fuel filter seen to.
Those few miles on the road meant the pump working on fuel weakened by petrol the whole way. Tank, lines, filter, then fresh fuel run through the whole system: that's the work, and the way the car was driven counts as much as the miles. The school run to the local primary school is one thing. Driving as far as Dundee, under 3 miles away, makes a very different task — as does any miles on the M90, under 25 miles from Charleston, with the engine running hard all the way.
Driven until it protested. Knocking, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and the motor is saying so. Whether it's the verge on Whittle Place, a lay-by or a side street, stop there then leave it. Lasting damage is very unusual when a car is pulled over quickly, and the fuel drain and flush-through that still go first sort it out.
What Charleston drivers get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing is removed by topping up — you're left with a fuller tank, still the same mix. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
Not so: a newer diesel copes with a bit of petrol. If anything, the reverse. A newer diesel sends its fuel through finer components at higher pressure, which makes the lubrication count more, not less.
Myth: "If it starts and drives, there's no damage done." This is the one that catches motorists. The motorist of a petrol engine fed diesel usually has no choice but to stop, since it will not run, and the damage stops there. Feed petrol to a diesel and it generally starts, ticks over and drives away like nothing has happened — all while its pump wears. Being able to run is not proof of being fine.
An outdated fix for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the car home." What petrol has thinned remains diluted, and the petrol remains in your tank regardless.
"Drain it yourself and you are sorted" — a myth, since after it has been running some petrol sits in the fuel filter and lines, ready to go straight back through the pump at the next start. Draining petrol into a can at the roadside is also really hazardous.
Why petrol in a diesel occurs so easily
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it simple: the petrol nozzle is the smaller of the two, and it slips into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol car at all. So the mistake runs one way.
It happens when habit and the vehicle stop matching. A new car, a hire car or a courtesy car. Two vehicles on one drive, one petrol, one diesel. Your normal forecourt, its pumps now in a different order. A train to catch, and a hurried fill on the way to Invergowrie. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it takes place. Add a back seat full of kids, a phone call or rain, and habit wins.
Avoiding petrol in a diesel next time you fill up in Charleston
- 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.
- Plenty of motors state the fuel inside the filler flap or on the cap, and so check there on your first fill in a car you do not know.
- Label the key. In a house 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 silly and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the pump.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck your phone away and keep your mind on the petrol pump.
- Add-on devices are available for vehicles without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol in your tank makes a weaker blend. It does not change what to do next, which is still not to crank it.
Put petrol in a diesel in Charleston already?
Short and simple, then, is the order of things. Do not turn the ignition on, and do not crank it. If you're still at the forecourt — BP or anywhere else — ask the staff to help you roll it clear of the petrol pump. Ring 0333 366 0103 next, with three facts — the fuel, the approximate volume, and if it's run.
Say so if it was AdBlue rather than petrol: it is a different fault, with its own page for Charleston, since AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel job around Charleston costs more than another
There is no fair single quote for this, because the four scenarios above are four different tasks. What moves the cost is chiefly which of them you are in. Next it is the share — how much petrol got in against how much the tank holds — and after that where the car is and whether a technician can reach it safely.
Three queries come first, before quoting, rather than after — what got in, how much, has it run — and that is the reason. Those replies turn a range into a straight figure.
About Charleston
Charleston is a suburban area located on the outskirts of Dundee, situated near the coast in eastern Scotland. Charleston sits at an elevation of 68 metres, overlooking the surrounding landscape, and is close to nearby places such as Gourdie and Menzieshill. Charleston is characterized by its predominantly flat-type housing, which is typical of many Scottish suburban areas. Charleston is approximately 2.9 miles from Dundee city centre, making it a convenient residential location.
Charleston and Dundee City: where our fuel drain cover runs
Petrol in diesel calls around Charleston — part of the DD postcode area — go to vans that likewise cover the locations around it, Gourdie, Menzieshill and Denhead of Gray included. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our technicians work, and the vehicle doesn't need to come to us.
In Charleston and still at the pump?
No position is better: that is where you are. Ring, and keep it switched off.