Diss: Petrol in a Diesel Car? How Worried to Be
Unstarted? Then less anxious than you likely are. Everyone in Diss starts with "have I wrecked it?", and the fair answer is usually no: petrol resting in your tank of any diesel stays harmless until priming, cranking or driving pulls it into the fuel system. Petrol in Diesel is who to ring, with your engine left off, and so it stays that way. Read on for three things: the effect petrol has inside a diesel motor, the clues of how far it has got, and the way to make sure you don't do it again.
What petrol in a diesel does to your engine
Two tasks fall to diesel on its route round a motor. Before it ignites, it lubricates — and then it burns. Built to very fine gaps, the fuel injectors and your pump rely on the diesel moving through them to keep their surfaces from wearing against one another.
Of these two jobs, petrol handles the first poorly and the second not at all. Being less viscous than diesel, petrol strips out the protection a fuel system needs, leaving a pump running on that mixture wearing itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is where you get the rattling.
Together, those leave the shape of the problem plain. Contact does not do the damage — movement does. A tank with petrol in it is a fuel problem. After the pump has been labouring on that petrol, a mechanical problem has started: anything shed by a pump that's wearing down is carried onward to the injectors with the fuel.
How bad is petrol in a diesel? Four situations we see around Diss
The best case there is: filled up, not once started. The petrol is inside your tank and only your tank, and the job is a drain and a flush where the vehicle stands. This is the one situation that can only really take place at a forecourt, as anywhere else the vehicle has been driven to get there.
The ignition switched on, or a short start. Once primed, the system has drawn petrol out of the tank as far as your filter and the fuel lines. Drain, flush, deal with the filter: still normally straightforward.
Those few miles driven meant the pump running on fuel diluted by petrol the whole way. The work is your tank, the lines, the filter and clean fuel through the whole circuit, and how hard the vehicle was driven counts as much as how far. Driving the children to Diss Church of England Junior Academy is one sort of trip. Any mileage on the M11, under 50 miles from Diss, means the engine has worked hard throughout, and a run to Norwich, under 25 miles away, is a very different task too.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone ragged. The engine is telling you your fuel is no longer acting like diesel. Whether it is the verge on Market Place, a lay-by or a side street, stop there and leave it. Permanent damage is very uncommon if a car is pulled over quickly, and the fuel drain and flush that still come first sort it out.
Myths Diss people hear about petrol in a diesel
False: topping up to full with diesel makes it fine. It doesn't. Nothing is removed when you top up — your tank simply carries more of the same mixture. A diesel fuel system does not accept petrol by percentage in the way that guidance supposes.
Not so: a modern diesel copes with a bit of petrol. If anything, the reverse. Lubrication matters more on modern diesels, not less, because their fuel passes through smaller components at higher pressure.
One myth that catches drivers out: if it starts and drives, it must be unharmed. Diesel in a petrol motor normally leaves a motor that will not run: the driver stops, and so does the harm. Whilst your pump wears, a diesel fed petrol normally starts, ticks over and drives away as if nothing has happened. Being able to run is not the same as being fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a distinct problem. That petrol is still inside your tank after that, and what it has diluted isn't put back.
"Drain it yourself and you are sorted" — a myth, because after it has been running some petrol sits in your filter and lines, waiting to go right back through your pump on your next start. On top of that, petrol emptied into a can by the road is truly hazardous.
Why petrol in a diesel occurs so easily
On purpose? Never. Through carelessness? Seldom, if ever. The petrol nozzle is the smaller of the two and slips into a diesel filler with almost no resistance; a diesel nozzle generally will not go into a petrol car at all. The forecourt makes it easy, and the error runs one way.
When routine and your car stop matching, it takes place. Hire cars, courtesy cars, and vehicles that are new to you. One petrol and one diesel on the driveway of the same household. A well-known forecourt with the pumps in a different order. A rushed fill en route to the nearest station with a train to catch. The first fill-up in a diesel Renault Megane after years of driving petrol is exactly the moment it occurs. Throw in rain, a phone call or a back seat full of children, and your hand repeats what it has always done.
Avoiding petrol in a diesel next time you fill up in Diss
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, yet not on every forecourt. The label is what counts.
- In a motor you do not know, look inside the flap over your filler or at the cap before your first fill: plenty of motors state the fuel type there.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, for a home with one of each.
- Say it before you lift it. On the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump. It sounds silly and it works.
- Mistakes like this are easy to make whilst your mind is on something else, so the phone goes away.
- Some diesels have a filler designed to block a petrol nozzle, and devices you can add exist for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the pump.
- Spotting it mid-fill? Stop at once. A weaker blend follows from less petrol in your tank, but the next step remains the same: do not crank it.
Petrol already in a diesel around Diss? Start here
Short and simple, then, is the order of things. Do not turn your ignition on, and do not crank it. If you are still at the forecourt — Morrisons or anywhere else — ask the staff to help you push the vehicle away from the pump. Phone 0333 366 0103 next, with three answers — your fuel, the rough quantity, and whether it's run.
Say so if it was AdBlue instead of petrol: it's a different issue, with its own page for Diss, because AdBlue brings corrosion and deposits instead of lost lubrication.
What makes one Diss petrol in a diesel task cost more than the next
The four situations above are four different tasks, so no single price for this would be fair. What moves your cost is mostly which of them you are in. The ratio counts next, meaning how much of the tank is petrol, followed by the location of the vehicle and whether reaching it is safe for a van.
That's why we ask three queries before pricing instead of after: what went in, how much, and whether it has run. A range turns into a straight figure once the answers are in.
About Diss and where it is
Diss is a town situated in the Waveney Valley in Norfolk, England, with a riverside setting along the River Waveney. Diss sits at an elevation of 32 metres and is located approximately 19 miles south of Norwich. Diss has a mix of old and new housing, with detached homes being the predominant type, and is surrounded by smaller villages such as Walcot Green and Brewers Green. Diss is also within commuting distance of London, being around 80 miles from the capital.
Diss and Norfolk: where our fuel drain cover runs
Diss waits in the IP postcode area, and our teams that answer petrol in diesel call-outs there work the locations near it as well — Walcot Green, Brewers Green and Westbrook Green among them. The car doesn't need to move to us: our engineers drain on a forecourt, in a supermarket car park, in a lay-by or on your own drive.
At the petrol pump in Diss, still?
The best place there is, then — that's where you are. Switched off it stays; then ring.