Petrol in a Diesel Car in Knatts Valley: How Worried Should You Be?
If it has not been started, you can worry far less than you likely are. Everyone in Knatts Valley starts with "have I wrecked it?", and the honest answer is normally no: petrol left inside the tank of a diesel stays harmless till priming, cranking or driving draws it into the system. Keep it like that: leave your engine off and phone Petrol in Diesel. Below, you will find what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you a second time.
The engine and petrol in a diesel: what happens
Passing through an engine, diesel does two things at the same time. It combusts, and before it ignites it lubricates. What keeps the surfaces inside your high-pressure pump and the fuel injectors from wearing down against each other is your diesel flowing through them — they're made to extremely fine tolerances.
Of those two jobs, petrol manages the first badly and the second never. A pump working on a petrol mixture is wearing itself out, since petrol is runnier than diesel and takes away the lubrication the fuel system depends on. Petrol is also made to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the knocking starts.
The shape of the problem is plain when you put those together. It is movement that causes the damage, not contact. Any tank with petrol in it is a fuel fault. Whatever a worn pump sheds travels on, carried by the fuel, into your injectors downstream, which is why a pump that has been working on that petrol is where a mechanical problem begins.
Knatts Valley, petrol in a diesel: four situations, from mild to major
The best case there is: filled up, never started. Being at a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With that petrol kept in your tank alone, it is drained and cleaned right where it stands, and nothing more is needed.
Ignition on, or started for a moment. Once primed, your system has drawn petrol from that tank up to the filter and the lines. Still usually easy: drain, flush, and your filter sorted.
Those few miles driven were the pump running on fuel weakened by petrol throughout. How hard the car was driven counts as much as how far, and the work covers your tank, the lines, the filter and clean fuel through the whole circuit. Short trips, like the school run to St. Edmund's Church of England Primary School, are one thing. A run as far as London, under 25 miles away, is a very different job. So is any miles on the M20, under 3 miles from Knatts Valley, where the motor has been working hard throughout.
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 your engine is telling you. Whether it's the verge on Knatts Lane, a lay-by or a side road, stop where you are and leave it. Long-term damage is very uncommon when a car is pulled over soon, and the drain and flush that still come first deal with it.
Stories Knatts Valley people hear about petrol in a diesel
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 fuller tank, still the same mix. That guidance supposes a diesel fuel system tolerates petrol by percentage. It doesn't.
Not so: a current diesel copes with a bit of petrol. Rather, the opposite. Protection counts more on current diesels, not less, because their fuel passes through more precise parts at higher pressure.
"It starts, it drives, so there is no harm" — the myth that trips up most people than any other. Feed diesel to a petrol engine and it usually will not run, and so the driver stops — and the damage stops with them. Whilst your pump grinds, a diesel fed petrol normally starts, ticks over and drives away as though nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. None of what petrol diluted is put back by it — and later, the tank still contains the petrol.
The next start draws petrol back round the pump from your lines and the filter, where some of that ends up after the motor has run. That is why a DIY tank drain does not sort it — a myth. It is also truly hazardous to drain petrol into a can at the kerbside.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. A diesel nozzle mostly won't go into a petrol motor, yet the slimmer petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and only in that direction.
It happens when habit and the car stop matching. Courtesy car, hire car, or a car that's brand new. Two vehicles on one drive, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. A hurried fill en route to Kemsing with a train to catch. A new-to-you diesel Renault Megane, its first fuelling, and a motorist used to petrol: exactly when it takes place. Add a back seat full of kids, a phone call or rain, and the hand wins.
Next time you fill up around Knatts Valley: preventing petrol in a diesel
- The label is what matters, and so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- In a vehicle you do not know, look inside the flap over the filler or at the cap before your first fill: plenty of cars state the fuel there.
- Label 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.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you lift the nozzle off the petrol pump. It seems daft and it does the trick.
- Mistakes like this are easy to make whilst your mind is on something else, so the phone goes away.
- Add-on devices exist for motors without one, and some diesels come with a filler that won't take a petrol nozzle. Helpful — but a safety net only, never a reason to stop checking the label.
- Stop as soon as you notice. Less petrol in that tank makes a thinner mix. It doesn't change what to do next, which is still not to start the vehicle.
Knatts Valley: already put petrol in a diesel?
Short and simple, then, is the order of things. Starting it is out, and so is switching on the ignition. If you're still at the forecourt — Texaco or anywhere else — ask the attendants to help you push it clear of the petrol pump. What went in, roughly how much, and whether it's run: tell us those when you phone 0333 366 0103.
Corrosion and deposits form the trouble with AdBlue, whereas petrol brings lost lubrication. So if it was AdBlue, say so — and read its own Knatts Valley page.
One petrol in a diesel job in Knatts Valley costs more than another. Why?
There is no honest single quote for this, since the four situations above are four different tasks. The situation itself does most of the work of moving your cost. Two things follow that: the petrol that went in as a proportion of what that tank holds, then the spot your car is in and whether a technician can reach it safely.
What was put in, how much, and if it's run — three questions we ask before costing, not after, for precisely that reason. Those replies turn a range into a straight figure.
About Knatts Valley itself
Knatts Valley is a small suburban area in Kent, situated inland at an elevation of 117 metres, and is located approximately 20 miles from London. Knatts Valley is characterized by its predominantly detached housing stock and is surrounded by nearby places such as Knockmill, East Hill, and Woodlands. Knatts Valley has a relatively small population of around 515 residents, and its proximity to London makes it a commuter-friendly location.
Knatts Valley and Kent: where our fuel drain cover reaches
The teams answering petrol in diesel jobs around Knatts Valley, in the TN postcode area, also work the spots around it, Knockmill, East Hill and Woodlands among them. The vehicle doesn't need to move to us: our technicians drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
Still at the petrol pump in Knatts Valley?
Then you are in the best spot there is. Keep it off. Phone.