Petrol in a Diesel Car in Green Tye: How Worried Should You Be?
Probably less than you already are — provided no one has started it. Everyone in Green Tye starts with "have I wrecked it?", and the honest answer is usually no: petrol left in that tank of a diesel remains harmless till priming, cranking or driving draws it into the system. Petrol in Diesel is who to ring, with the engine left off, and so it stays that way. What petrol actually does to a diesel, how to judge how far it's gone, and how to keep it from happening again: that is the remainder of this page.
Petrol in a diesel: what does it do to your engine?
Two jobs fall to diesel on its route round a motor. It lubricates first, and only then does it burn. What keeps the surfaces inside your high-pressure pump and your injectors from grinding against one another is the diesel flowing through them — they are built to very fine clearances.
Of those two jobs, petrol manages the first poorly and the second never. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump on the mixture wearing itself. It's also made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the knocking.
The shape of the trouble is clear when you put those together. It's circulation that causes the harm, not contact. Where that petrol is only inside that tank, it is a fault of fuel, nothing more. A pump that has been labouring on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the injectors further on.
Green Tye, petrol in a diesel: four situations, from mild to major
Fuelled up, never started. The best case there is. That petrol is in your tank and just your tank, and the task is a drain and a flush where the car stands. This is the one situation that can only really happen on a forecourt, as anywhere else the vehicle has been driven to get there.
The ignition switched on, or a brief start. Your system has been primed, so petrol has left your tank and got to your filter and the lines. That's usually still a straightforward job — a drain, a flush, and your filter seen to.
Those few miles on the road were the pump working on fuel thinned by petrol throughout. Tank, lines, filter, then fresh fuel put through the whole circuit: that is this work, and the way the car was driven matters as much as the mileage. Driving the kids to St Andrew's CE Primary School and Nursery is one sort of trip. Very different again: a trip to Chelmsford, under 25 miles away, or some mileage on the M11, under 5 miles from Green Tye, where the engine kept labouring hard.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the engine signalling fuel that no longer runs like diesel. Stop wherever you are — the verge on Ducketts Lane, a lay-by, a side street — and leave the car where it is. What goes first is still the drain and flush, and that sorts it out, with long-term damage very unusual if a vehicle is pulled over soon.
Myths Green Tye drivers 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." Nothing comes out when you top up — that tank just holds more of the same mixture. A diesel fuel system doesn't tolerate petrol by percentage in the way that advice supposes.
"Current diesels can handle a little petrol" — a myth, and nearer the opposite. Lubrication matters more on current diesels, not less, since their fuel runs through finer components at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that catches people. A petrol motor fed diesel generally won't run, so the motorist stops and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Running doesn't mean fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate fault. None of what petrol weakened gets put back by it — and afterwards, the tank still contains the petrol.
Once the motor has been run, part of that petrol sits in your filter and the lines, not that tank — and the next start pulls it straight back through the pump. So the myth "drain your tank yourself and you're sorted" doesn't hold. Also, a can of petrol filled by the roadside is truly hazardous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol vehicle at all. So the slip runs one way.
It occurs when routine and your car stop matching. Hire cars, courtesy cars, and cars that are new to you. Households running one of each, petrol and diesel. A forecourt you know, but with its pumps arranged differently. A train to catch, and a hurried fill on the way to Bishops Stortford. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is exactly the moment it happens. Add a back seat full of children, a phone call or rain, and habit takes over.
Avoiding petrol in a diesel next time you fill up around Green Tye
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the pump's label; the colour is just a hint.
- Many vehicles state the fuel inside your filler flap or on the cap, and so check there on the first fill in a car you do not know.
- Mark 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 intending to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump. It seems daft and it does the trick.
- Whilst you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Add-on devices exist for vehicles without one, and some diesels come with a filler that will not take a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol in that tank means a thinner mix. What to do next doesn't change, though — still do not start the vehicle.
Green Tye: already put petrol in a diesel?
Short and simple, then, is the order of things. Starting it is out, and so is turning on your ignition. Ask the staff to help you push it clear of the petrol pump if you are still at the forecourt, whether that's the nearest petrol station or somewhere else. Call 0333 366 0103 next, with three answers — the fuel, the approximate quantity, and whether it's run.
Say so if it was AdBlue instead of petrol: it's a separate issue, with its own page for Green Tye, because AdBlue brings corrosion and deposits rather than lost lubrication.
One petrol in a diesel task in Green Tye costs more than another. Why?
There is no fair single price for this, because the four scenarios above are four different tasks. Which of them you're in is mostly what moves your cost. Where your car is matters too, and whether a technician can safely get to it, after the share of petrol to what your tank holds.
Before any quote, not after, come three queries: the fuel that went in, the quantity, and if it's run. That is why. A range turns into a straight figure when those replies are in.
About Green Tye and where it is
Green Tye is a small village in Hertfordshire, situated near the River Lea and close to the villages of Perry Green and Allens Green. Green Tye has a population of around 514 people and is characterized by its predominantly detached housing stock. Green Tye sits at an elevation of 92 metres, within the gently rolling countryside of the Eastern region, and is located approximately 25 miles from London. Green Tye is also near the larger settlement of Hadham Cross and the city of Chelmsford, which is 18 miles away.
Green Tye and Hertfordshire: where our fuel drain cover runs
Perry Green, Allens Green and Hadham Cross are among the spots around Green Tye that the same vans work, answering petrol in diesel jobs across Green Tye's SG postcode area. The car doesn't need to come to us: we drain at a forecourt, in a supermarket car park, in a lay-by or on your own driveway.
At the pump around Green Tye, still?
Then you're in the best position there is. Turned off it remains; then call.