Petrol in a Diesel Car in Quarhouse: How Worried Should You Be?
Not started? Then less worried than you probably feel. Petrol resting in a diesel tank does nothing to the motor until something pulls it through the system — your ignition priming your pump, your starter, or the drive on its own. So the honest answer to the first question anyone around Quarhouse asks, "have I wrecked it?", is usually no. Petrol in Diesel is who to ring, with the engine kept off, so it remains that way. What petrol actually does to a diesel, how to judge how far it has travelled, and how to stop it from happening a second time: that is the rest of this page.
Your engine and petrol in a diesel: what happens
Passing through a motor, diesel does two things at the same time. It ignites, and before it combusts it lubricates. Extremely fine tolerances go into the injectors and the high-pressure fuel pump, and only the diesel flowing through stops their surfaces grinding together.
The second job petrol doesn't do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running 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 hear the rattling.
Together, those make the shape of the trouble plain. Not contact but circulation is what does the damage. A tank with petrol in it is a fuel issue. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the fuel injectors downstream.
How bad is petrol in a diesel? Four situations we see in Quarhouse
Filled up, and never started: no case is better. The petrol is inside the tank and just the tank, and the task is a drain and a flush where the car stands. This is the one situation 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 second. With the fuel system primed, the lines and filter now contain petrol that came from the tank. Still usually straightforward: drain, flush, and the filter seen to.
A few miles driven, and the pump has spent every one of them labouring on weakened fuel. How hard the vehicle was driven counts as much as how far, and this work covers your tank, your lines, your filter and fresh fuel through the whole circuit. Short trips, such as the school run to Brimscombe Church of England (VA) Primary School, are one matter. Any miles on the M5, under 10 miles from Quarhouse, means the engine has worked hard throughout, and a run to Gloucester, under 15 miles away, makes a very different task too.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. The motor is telling you your fuel is no longer acting like diesel. Pull up wherever you are — the verge on Bourne Lane, a lay-by, a side street — then leave the car where it is. The drain and flush-through still come first, and they take care of it: when a car is pulled over soon, long-term damage is very rare.
Petrol in a diesel myths Quarhouse motorists hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you're left with a fuller tank, still the same mix. That advice supposes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A current diesel runs its fuel through more precise components at higher pressure, which makes the lubrication count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there is no damage done." Feed diesel to a petrol engine and it generally will not run, and so the driver stops — and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Being able to run is not the same as being fine.
Not so: a two-stroke additive makes it safe to drive home. It was an old fix, supposed for another problem. That petrol is still in your tank after that, and whatever it has weakened is not put back.
The next start draws petrol back round the pump out of the lines and your filter, where some of that ends up once the engine has been run. That's why a DIY tank drain does not leave you sorted — a myth. Clearing petrol into a can by the kerbside is also genuinely dangerous.
How it happens: petrol in a diesel
Carelessness is seldom the cause, and nobody means to do it. A diesel nozzle mostly won't fit a petrol motor, yet the narrower petrol nozzle goes into the filler of a diesel nearly without resistance — so forecourts make this one mistake simple, and only in that direction.
Habit and your car getting out of step is when it occurs. Any vehicle that is new to you — a hire car, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. The pumps in a different order on a well-known forecourt. Rushing for a train outside Stroud and fuelling up en route. Exactly the moment it happens: after years of driving petrol, a driver fills a diesel Volkswagen Passat for the first time. Add rain, a phone call or a back seat full of kids, and your hand repeats what it has always done.
Next time you fill up in Quarhouse: avoiding petrol in a diesel
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Check the petrol pump's label; the colour is just a hint.
- Inspect your filler flap. Plenty of vehicles state the fuel inside the flap or on the cap. Look at it on the first fill in any vehicle you don't know.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, in a household with one of each.
- 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 pump. It seems daft and it does the trick.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away and keep your mind on the petrol pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and add-on devices exist for the remainder. Count it as a backstop, and keep checking the petrol pump.
- The moment you realise, stop: less petrol inside that tank makes a thinner mixture. What to do next doesn't change, though — still don't crank it.
Quarhouse: already put petrol in a diesel?
Then, there is only a short order of things. Starting it is out, and so is switching on your ignition. Yet on the forecourt, at Murco or anywhere else? Ask the attendants to help you roll the car clear of the petrol pump. Then ring 0333 366 0103 and tell us what was put in, about how much, and if it's run.
Say so if it was AdBlue instead of petrol: it is a separate issue, with its own page for Quarhouse, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel job in Quarhouse costs more than another
There is no honest single price for this, because the four scenarios above are four different tasks. What moves your cost is mostly which of them you're in. Where the car is counts too, and whether a van can safely get to it, after the ratio of petrol to what your tank takes.
Ahead of any quote, not after, come three queries: the fuel that got in, its volume, and if it has run. That is why. A range turns into a straight figure when those replies are in.
About Quarhouse and its setting
Quarhouse is a locality in Gloucestershire, situated on the riverside at an elevation of 102 metres, with detached housing being the predominant type of accommodation. Quarhouse lies near the city of Gloucester, approximately 10 miles away, and is also close to other nearby places such as Brimscombe and Brownshill. Quarhouse is a relatively small community, with a population of around 605 people, and is located in the South West region of England, about 89 miles from London.
Fuel drain cover across Gloucestershire, Quarhouse included
The teams answering petrol in diesel calls in Quarhouse, in the GL postcode area, equally work the spots around it, Brimscombe, Knave-in-hole and Brownshill included. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and your vehicle doesn't need to move to us.
In Quarhouse and still at the pump?
Then you are in the best spot there can be. Keep the car turned off, and ring.