How Worried Should You Be? Petrol in a Diesel Car in Moredon
Not started? Then less worried than you probably are. "Have I ruined it?" is the first thing anyone around Moredon asks, and the honest answer is usually no, because petrol resting in a diesel tank hurts nothing till it's dragged through your fuel system — by ignition priming, by your starter, or by driving. Petrol in Diesel is who to call, with the engine left off, and so it remains that way. What petrol actually does to a diesel, how to judge how far it has travelled, and how to keep it from happening a second time: that's the rest of this page.
What petrol in a diesel does to your engine
Two jobs fall to diesel on its journey round a motor. It burns, and before it burns it lubricates. Very fine tolerances are built into your injectors and the high-pressure pump, and only the diesel running through stops their surfaces grinding together.
Badly at the first, not at all at the second: that's petrol. The rattling comes from petrol being designed not to ignite when compressed, which is precisely the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips out the protection your system hinges on, and any pump running on that blend is wearing itself.
Combined, those make the shape of the trouble clear. Contact doesn't do the harm — circulation does. All a tank with petrol in it amounts to is a fuel issue. A pump that has been running on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with the fuel to the fuel injectors further on.
Petrol in a diesel in Moredon: how serious is it? Four cases
The best case there can be: filled up, not once started. At a forecourt, and really only there, that petrol is still confined to the tank — since anywhere else the vehicle was driven to reach it. The job is emptying and rinsing on the spot.
Ignition on, or started for a moment. Your system has been primed, and so petrol has left that tank and reached the filter and the lines. That's normally still a straightforward job — a drain, a flush, and your filter dealt with.
Some miles driven, and the pump has spent every one of them labouring on weakened fuel. How hard the car was driven matters as much as how far, and the work takes in the tank, the lines, your filter and clean fuel through the whole system. Short trips, such as the school run to Haydon Wick Primary School, are one thing. Very different again: a trip to Oxford, under 50 miles away, or any mileage on the M4, under 5 miles from Moredon, where your engine never stopped running hard.
Driven on till it complained — knocking, smoke, an uneven idle, a soft throttle. That is the engine telling you its fuel no longer is behaving like diesel. Whether it's the verge on Barton Road, a lay-by or a side road, stop where you are then leave it. A car stopped early very rarely has lasting damage, because the fuel drain and the flush, which still come first, take care of it.
Stories Moredon motorists hear about petrol in a diesel
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." A bigger tank of the same mix is all it gives, since topping up takes out nothing. Percentage isn't how a diesel fuel system tolerates petrol, whatever that advice assumes.
If anything, the opposite is true. Myth: "A newer diesel can cope with a bit of petrol." Lubrication matters more on newer diesels, not less, since their fuel passes through more precise components at higher pressure.
Myth: "If it starts and drives, there's no damage done." This is the one that catches people. Diesel in a petrol motor normally means a motor that will not run: the driver stops, and so does the damage. Feed petrol to a diesel and it usually fires up, idles and drives away like nothing has happened — all the while its pump wears. Running isn't the same as fine.
Myth: "Add some two-stroke oil and drive the car home." It is an outdated fix for a distinct fault. What petrol has thinned stays thinned, and that petrol stays inside your tank regardless.
The next start sends petrol back round the pump out of the lines and the 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. And, a can of petrol drained by the roadside is truly hazardous.
Why petrol in a diesel takes place at all
A careless moment is seldom the cause, and no one means to do it. 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, while a diesel nozzle generally won't go into a petrol car at all. So the mistake runs one way.
The moment habit stops matching the car is the moment it happens. Courtesy car, hire car, or a vehicle that is new. Two cars on one driveway, one petrol, one diesel. Your ordinary forecourt, its pumps now in a different order. Racing for a train at Swindon and filling up en route. Years of petrol motors behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up around Moredon: avoiding petrol in a diesel
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Go by the label on the pump, not the colour.
- Many motors state the fuel type inside your filler flap or on the cap, and so check it on your first fill in any motor you don't know.
- Label your key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car gets its first tank. It seems silly. It works.
- Put the phone away. This is an easy mistake to make while you are thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels come with a filler designed to refuse a petrol nozzle, and add-on devices are available for the rest. Count it as a backstop, then keep checking the pump.
- Less petrol makes a thinner mixture, so stop as soon as you notice — though remembering that the next stage is unchanged. It is still not to fire it up.
Moredon: already put petrol in a diesel?
In that case, there is only a short order of things. Leave it unstarted, with the ignition switched off as well. Yet on the forecourt, at Asda or anywhere else? Ask the staff to help you push it clear of the pump. Next, 0333 366 0103. We'll ask what got in, roughly how much, and if it has been run.
Corrosion and deposits are the trouble with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Moredon page.
One petrol in a diesel job around Moredon costs more than another. Why?
There is no honest single quote for this, because the four situations above are four different tasks. The scenario itself does most of the work of moving your cost. Next it's the share — how much petrol was put in against how much the tank holds — and after that where your car is and whether a technician can get to it safely.
That is why our engineers ask three questions before pricing instead of after: what went in, how much, and if it's run. The answers turn a range into a straight figure.
About Moredon itself
Moredon is a suburban area in Wiltshire, situated near the River Ray and close to the nearby places of Haydon Wick, Greenmeadow, and Rodbourne. Moredon sits at an elevation of around 110 metres, with semi-detached housing being the predominant type of accommodation. Moredon is located approximately 26 miles from Oxford and 72 miles from London, making it a commuter-friendly location. Moredon has a population of around 8031 residents, who enjoy the area's riverside setting.
Moredon and Wiltshire: where our fuel drain cover reaches
Haydon Wick, Greenmeadow and Rodbourne are among the locations around Moredon that the same vans work, answering petrol in diesel jobs across Moredon's SN postcode area. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers drain, and the car doesn't need to come to us.
At the pump in Moredon, still?
The best place there is, then — that is where you are. Ring, and leave it switched off.