Should You Worry? Petrol in a Diesel Car in Higham Wood
Far less than you probably are, if it has not been started. Until your ignition primes the pump, the starter turns, or your car is driven, petrol in a diesel tank just waits there and does no harm. Which makes the truthful reply to that first Higham Wood question — "have I ruined it?" — usually no. To leave the car like that, call Petrol in Diesel then leave your engine alone. The rest of this page explains what petrol really does to a diesel, how to tell how far it has got, and how to make sure it does not happen to you again.
Inside your engine: what petrol in a diesel does
On its way through a motor, diesel does two tasks. It combusts, and before it burns it protects. Very fine clearances are built into the injectors and your high-pressure pump, and just the diesel flowing through stops their surfaces grinding together.
The second task petrol does not do at all, and the first it does badly. A pump working on a petrol blend is wearing itself out, because petrol is runnier than diesel and takes away the protection the fuel system relies on. Petrol is also made to resist igniting under compression — the reverse of what a diesel wants from its fuel — and that is where the rattling comes.
Put these together and the shape of the problem is plain. Contact doesn't do the harm — circulation does. Where the petrol is only inside the tank, it is a fault of fuel, nothing more. Whatever a worn pump sheds goes on, borne by the fuel, into the injectors downstream, which is why a pump that has worked on the petrol is where a mechanical issue starts.
Higham Wood, petrol in a diesel: four cases, from mild to major
Fuelled but never started — as good as it gets. Being at a forecourt is what makes this possible: elsewhere, the vehicle has been driven there to begin with. With the petrol held inside that tank alone, it's emptied and purged right where it stands, and nothing more is needed.
Ignition on, or started for a second. Once primed, the system has drawn petrol out of that tank as far as the fuel filter and your lines. Still usually easy: drain, flush, and the fuel filter sorted.
A couple of miles driven, and the pump has spent each of them labouring on diluted fuel. How hard your car was driven counts as much as how far, and the work covers your tank, the lines, the fuel filter and clean fuel through the whole system. Short trips, such as the school run to Woodlands Primary School, are one matter. Very different a second time: a run to London, under 50 miles away, or some miles on the M26, under 10 miles from Higham Wood, where your engine never stopped working hard.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone lumpy. The fuel isn't acting like diesel any more, and your engine is telling you. Whether it's the verge on Higham Lane, a lay-by or a side road, stop where you are and leave it. Permanent damage is very uncommon when a car is stopped early, and the drain and flush-through that still go first take care of it.
Higham Wood drivers and that petrol in a diesel stories they hear
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed when you top up — that tank simply carries more of the same blend. That advice assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
If anything, the reverse holds. Myth: "A modern diesel can cope with a bit of petrol." Lubrication matters more on newer diesels, not less, since their fuel runs through finer parts at higher pressure.
This is the one that fools drivers. Myth: "If it starts and drives, there's no damage done." A petrol motor fed diesel generally will not run, so the motorist stops and the damage stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, while the pump grinds. A running engine doesn't mean fine.
An outdated workaround for a different problem is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It does not put back what petrol has thinned, and the petrol is still in that tank later.
Myth: "Drain the tank yourself and you are sorted." After your engine has been run, some of the petrol is no longer in that tank: it's in your filter and your lines, and it goes straight back through the pump at your next start. On top of that, petrol emptied into a can by the road is genuinely risky.
Petrol in a diesel: how does it occur?
It is seldom carelessness, and nobody does it on purpose. 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, whilst a diesel nozzle generally will not go into a petrol car at all. So the slip runs one way.
Routine and your car getting out of step is when it happens. Any car that's new to you — a hire car, on loan as a courtesy car, or brand new. A household with one petrol and one diesel on the drive. A forecourt you know, but with its pumps laid out differently. A train to catch, and a rushed fill on the way to Tonbridge. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: precisely when it takes place. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel on your next fill-up in Higham Wood
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most generally do. Check the petrol pump's label; the colour is only a hint.
- The first fill in a strange car is the time to check your filler flap — on it, or on the cap, many motors state which fuel to use.
- A coloured fob or a sticker on the diesel's key does more than any amount of meaning to remember, in a house with one of each.
- It seems silly and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the petrol pump.
- 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.
- Some diesels have a filler designed to refuse a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the petrol pump.
- Spotting it mid-fill? Stop there and then. A weaker mix results from less petrol in the tank, yet the next step stays the same: don't fire it up.
Already put petrol in a diesel in Higham Wood?
In that case, there's only a short order of things. Leave it unstarted, with the ignition off too. If you are still at the forecourt — Three Elm Service Station or anywhere else — ask the staff to help you roll the vehicle away from the petrol pump. Next, 0333 366 0103. We will ask what went in, about how much, and if it's been run.
Corrosion and deposits form the trouble with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and read its own Higham Wood page.
What makes one Higham Wood petrol in a diesel task cost more than the next
An honest single price does not exist here: four situations, four separate tasks. Chiefly, the cost shifts with which situation you're in. The proportion counts next, meaning how much of the tank is petrol, followed by the position of the car and whether getting to it is safe for our van.
Before any quote, not after, we ask three questions: your fuel that was put in, its amount, and whether it has run. That's why. Their replies are what change a range into one firm number.
About Higham Wood, briefly
Higham Wood is a suburban area in Kent, situated near the River Medway at an elevation of around 40 metres. Higham Wood lies on the outskirts of Tonbridge, close to nearby places such as Hadlow Stair, Parkers Green, and Cage Green. Higham Wood has a population of approximately 5133 people, predominantly living in semi-detached housing. Higham Wood is located about 27 miles from London, making it a commuter-friendly area.
Higham Wood and Kent: where our fuel drain cover reaches
Hadlow Stair, Parkers Green and Cage Green are among the locations around Higham Wood that the same teams work, answering petrol in diesel jobs across Higham Wood's TN postcode area. Our technicians drain wherever the vehicle is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the petrol pump in Higham Wood, still?
The best spot there is, then — that's where you are. Keep it off. Call.