Should You Worry? Petrol in a Diesel Car in Burwood Park
Provided it has not been started, you can worry less than you likely are. Everyone around Burwood Park starts with "have I ruined it?", and the honest answer is generally no: petrol resting in the tank of any diesel stays harmless till priming, cranking or driving draws it into your fuel system. To keep the car that way, call Petrol in Diesel then leave the motor alone. What petrol actually does to a diesel, how to gauge how far it's travelled, and how to stop it from happening a second time: that's the remainder of this page.
Inside your engine: what petrol in a diesel really does
Two tasks fall to diesel on its journey round a motor. It lubricates first, and only then does it burn. Very fine clearances are built into your injectors and the high-pressure pump, and only the diesel running through stops their surfaces grinding together.
Petrol does the first task poorly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump running on the mixture to wear itself. It's equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the clattering.
Taken together, they make clear the shape the trouble has. Not contact but circulation is what causes the damage. All a tank with petrol in it amounts to is a fuel issue. The beginning of a mechanical one is a pump that has been working on that petrol — and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
Four scenarios our engineers see around Burwood Park: how serious is petrol in a diesel?
The best case there is: filled up, not once started. Being on a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With that petrol held in your tank alone, it is drained and cleaned on the spot, and nothing more is needed.
Started for a second, or just the ignition on. With the fuel system primed, the lines and filter already contain petrol that came from your tank. Drain, flush, see to the filter: still normally easy.
Driven a couple of miles. Now your pump has spent these miles running on thinned fuel. The work is the tank, the fuel lines, the filter and fresh fuel through the entire system, and how hard the vehicle was driven matters as much as how far. On the school run to Cleves School, the mileage is short. Any mileage on the M25, under 3 miles from Burwood Park, means the engine working hard throughout, and a run to Westminster, under 25 miles away, makes a very different job as well.
Knocking, a ragged idle, smoke, a throttle gone soft: driven until it complained. The fuel isn't behaving like diesel any more, and the motor is saying so. Leave it where it stops: a lay-by, a side street, the verge on Burwood Road. Lasting damage is very rare when a vehicle is stopped early, and the fuel drain and flush-through that still go first sort it out.
What Burwood Park people get told about petrol in a diesel — and the stories in it
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 mixture. Percentage is not how a diesel fuel system copes with petrol, however much that advice assumes.
"Newer diesels can handle a little petrol" — a myth, and closer to the opposite. A current diesel runs its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
This is the one that catches drivers. Myth: "If it starts and drives, there is no harm done." The driver of a petrol engine fed diesel usually stops, because it will not run, and the harm stops there. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, whilst the pump wears. A running engine does not mean fine.
Myth: "Add some two-stroke oil and drive the car home." It is an old fix for a separate issue. It doesn't put back what petrol has diluted, and that petrol is still in that tank later on.
The next start draws petrol back round your pump out of the lines and the fuel filter, where some of that ends up once the engine has run. That's why a DIY tank drain does not sort it — a myth. Draining petrol into a can at the kerbside is also genuinely hazardous.
How petrol ends up: petrol in a diesel
A careless moment is seldom the cause, and nobody means to do it. The petrol nozzle is the slimmer of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol car at all. The forecourt makes it simple, and the mistake runs one way.
It takes place when routine and the vehicle stop matching. A 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. Your ordinary forecourt, its pumps now in a different order. A rushed fill on the way to Walton-On-Thames with a train to catch. The first fill-up in a diesel Volkswagen Tiguan after years of driving petrol is precisely the moment it takes place. The hand does what it has always done once you add rain, a phone call or a back seat full of children.
Next time you fill up around Burwood Park: preventing petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Read the petrol pump's label; the colour is just a hint.
- In a motor you don't know, look inside the flap over the filler or at the cap before the first fill: plenty of cars state the fuel there.
- Mark the key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- It seems silly and it works: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump.
- Mistakes like this are easy to make whilst your mind is on something else, so your phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to reject a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a backstop, then keep reading the petrol pump.
- Less petrol makes a thinner mix, so stop as soon as you realise — while remembering that the next stage is unchanged. It is still not to fire it up.
Put petrol in a diesel in Burwood Park already?
Then the order of things is short. Don't crank it, and do not switch your ignition on. If you are still on the forecourt — BP or anywhere else — ask the staff to help you roll the car away from the pump. What was put in, about how much, and whether it has run: tell us those when you ring 0333 366 0103.
If it was AdBlue and not petrol, say so. That's a different problem — corrosion and deposits rather than lost lubrication — and it has its own page for Burwood Park.
Why one petrol in a diesel job in Burwood Park costs more than another
Four different tasks sit behind the four situations above — which is why there's no fair single quote. Mostly, your cost moves with which situation you are in. Two things come after that: the petrol that went in as a proportion of what the tank holds, then the spot your car is in and whether a van can reach it safely.
What went in, how much, and whether it has run — three queries our engineers ask before costing, not after, for precisely that reason. With those answers, you get a straight figure instead of a range.
About Burwood Park and where it is
Burwood Park is a small village in Surrey, situated inland at an elevation of 39 metres, and is located approximately 16 miles from London. Burwood Park is characterized by its predominantly detached housing stock, reflecting its suburban residential nature. Burwood Park sits near several other local places, including Whiteley Village, Oatlands Park, and Hersham, and is home to around 744 residents.
Across Surrey and in Burwood Park: fuel drain cover
The teams answering petrol in diesel call-outs in Burwood Park, in the KT postcode area, also work the locations near it, Whiteley Village, Oatlands Park and Hersham included. No need to move your vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places where we work.
Still at the petrol pump around Burwood Park?
In that case, you could not be in a better position. Keep it off. Call.