Petrol in a Diesel Car in Millbrook: How Worried Should You Be?
Probably less than you already are — as long as nobody has started the vehicle. "Have I wrecked it?" is the first question anyone around Millbrook asks, and the honest answer is usually no, since petrol resting in a diesel tank harms nothing until it is drawn through your fuel system — by ignition priming, by the starter, or by being driven. Leave the engine off and call Petrol in Diesel — that keeps it like that. Read on for three things: the effect petrol has inside a diesel engine, the signs of how far it has spread, and the way to make sure you never do it again.
Inside the motor: what petrol in a diesel really does
On its way through an engine, diesel does two jobs. It lubricates to begin with, and after that does it burn. The high-pressure pump and the fuel injectors are built to extremely fine tolerances, and the diesel passing through them is what keeps those surfaces from grinding against each other.
Poorly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump on the mixture wearing itself. It's equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you get the clattering.
Seen together, they show what shape the problem takes. Not contact but movement is what causes the harm. Where that petrol is only inside that tank, it's a fault of fuel, nothing more. The start of a mechanical problem is a pump that has been running on that petrol — and whatever a worn pump sheds moves on with your fuel to the injectors downstream.
Four situations we see in Millbrook: how serious is petrol in a diesel?
Filled up, not once started. The best case there can be. That petrol is inside your tank and only the tank, and the task is a drain and a flush where your car stands. This is the one scenario that can only really occur on a forecourt, because anywhere else the car has been driven to get there.
Ignition on, or started for a moment. With your system primed, your lines and filter already hold petrol that has come from the tank. Drain, flush, see to your filter: still normally straightforward.
Those few miles on the road were your pump working on fuel diluted by petrol the whole way. Mileage is only half of that; how hard it was driven counts just as much. Either way this work includes that tank, your lines, the fuel filter and clean fuel through the whole circuit. Driving the children to Millbrook CofE Primary School is one sort of trip. Very different a second time: a run to Plymouth, under 5 miles away, or any distance on the M5, under 50 miles from Millbrook, where the engine kept running hard.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The fuel is not behaving like diesel any more, and your motor is telling you. Pull up on the spot — on the verge on Fore Street, at the kerb, down a side road — and do not move it. A car stopped early very seldom has lasting damage, because the drain and the flush, which still go first, take care of it.
Stories Millbrook 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 comes out when you top up — that tank just carries more of the same mixture. That guidance presumes a diesel fuel system handles petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. A modern diesel sends its fuel through finer components at higher pressure, which makes the protection count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no damage done." The motorist of a petrol motor fed diesel usually stops, since it will not run, and the damage stops there. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. 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 different problem. None of what petrol weakened gets put back by it — and afterwards, your tank still holds that petrol.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in your filter and lines, waiting to go straight back through the pump on your next start. Emptying petrol into a can by the kerbside is also genuinely hazardous.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it simple: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle mostly will not go into a petrol motor at all. So the mistake runs one way.
Routine and the car getting out of step is how it happens. A vehicle that is new to you — a hire car, on loan as a courtesy car, or brand new. Households running one of each, petrol and diesel. Your usual forecourt, its pumps suddenly in a different order. A train to catch, and a hurried fill en route to Devonport. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Golf for the first time. With rain, a call arriving, or a car full of children to deal with, your hand simply does what it has always done.
Next time you fill up around Millbrook: avoiding petrol in a diesel
- The label is what counts, and so check the petrol pump rather than the colour: in the UK unleaded handles are normally green and diesel black, but not on every forecourt.
- In a car you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of motors state the fuel there.
- Label the key. In a home 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 sounds daft and it works: on your first fill in a new or hired car, say "diesel" out loud 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.
- Some diesels have a filler built to refuse 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 checking the pump.
- Less petrol makes a weaker blend, and so stop as soon as you realise — though remembering that your next stage is unchanged. It's still not to start the car.
Petrol already in a diesel in Millbrook? Start here
Then, there's only a short order of things. Do not crank it, and do not turn your ignition on. The attendants at the forecourt — whether at Esso itself or wherever you filled up — will normally help roll it clear of the pump if you ask. Next, 0333 366 0103. We will ask what went in, roughly how much, and if it's been run.
If it was AdBlue instead of petrol, say so. That is a separate issue — corrosion and deposits and not lost protection — and it has its own page for Millbrook.
Why one petrol in a diesel task around Millbrook costs more than another
There is no honest single price for this, because the four scenarios above are four different jobs. What shifts the cost is mostly which of them you are in. The share counts next, meaning how much of your tank is petrol, followed by the location of the car and whether reaching it is safe for a technician.
That is why our engineers ask three questions before quoting instead of after: what got in, how much, and whether it has run. With the replies, there is a straight figure instead of a range.
About Millbrook
Millbrook is a small coastal village in Cornwall, situated near the Rame Peninsula and close to the city of Plymouth. Millbrook sits at a low elevation of around 6 metres, with its terraced housing reflecting the village's historical development. Millbrook is part of a wider area that includes nearby settlements like Insworke and Kingsand, and it is located within a short distance of the Devon border. Millbrook has a population of approximately 1473 residents, who live in a community that is connected to the larger city of Plymouth.
Fuel drain cover across Cornwall, Millbrook included
Our vans answering petrol in diesel calls in Millbrook, in the PL postcode area, also work the places near it, Insworke, Tregonhawke and Kingsand included. No need to move the car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all locations where we work.
At the pump around Millbrook, still?
The best spot there is, then — that's where you are. Leave the car turned off, and ring.