How Worried Should You Be? Petrol in a Diesel Car in Perrymead
Likely less than you are now — provided nobody has started the vehicle. Till the ignition primes the pump, the starter cranks, or your vehicle is driven, petrol in a diesel tank simply rests there and does no harm. Which means the honest reply to the first Perrymead query — "have I ruined it?" — usually no. Leave the motor off then phone Petrol in Diesel — that is how you keep it like that. Further down, this page sets out what petrol actually does inside a diesel, how far it may have got, and how to stop it happening to you again.
The motor and petrol in a diesel: what goes on
Two tasks fall to diesel on its journey round a motor. It combusts, and before it combusts it lubricates. The high-pressure pump and your injectors are designed to extremely fine gaps, and your diesel passing through them is what stops those surfaces from wearing down against each other.
Of those two tasks, petrol manages the first poorly and the second never. A pump working on a petrol mixture is wearing itself out, because petrol is thinner than diesel and takes away the lubrication your fuel system depends on. Petrol is also designed to resist igniting under compression — the opposite of what a diesel needs from its fuel — and that is where the clattering starts.
Combined, those leave the shape of the trouble clear. Contact does not do the harm — movement does. Petrol in the tank is a fuel fault. Whatever a worn pump sheds travels on, carried by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical issue begins.
How bad is petrol in a diesel? Four scenarios our engineers see in Perrymead
Filled up, and not started: no case is better. At a forecourt, and truly only there, that petrol is still limited to the tank — because everywhere else the vehicle was driven to reach it. The task is draining and cleaning on the spot.
A moment's running, or merely your ignition on. Once primed, the system has drawn petrol out of your tank as far as your filter and your lines. That is normally still an easy job — a drain, a flush, and your filter seen to.
Driven a few miles. Now your pump has spent those miles labouring on thinned fuel. The work is the tank, the lines, your filter and fresh fuel through the entire circuit, and how hard your car was driven matters as much as how far. On the school run to Widcombe Infant School, the miles is short. Driving as far as Bath, under a mile away, makes a very different job — as does any miles on the M4, under 10 miles from Perrymead, with the motor working hard all the way.
Driven until it protested. Knocking, an uneven idle, smoke, a throttle that has gone soft. The engine is telling you the fuel is no longer acting like diesel. Pull up on the spot — on the verge on Pope's Walk, at the kerb, down a side road — and do not move it again. A car pulled over soon very seldom has lasting damage, as the fuel drain and the flush, which still go first, deal with it.
Myths Perrymead motorists hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Topping up takes out nothing; it gives you a fuller tank of the same mixture. Percentage is not how a diesel fuel system tolerates petrol, whatever that advice assumes.
"Newer diesels can handle a little petrol" — a myth, and nearer the opposite. At higher pressure, through more precise components: that's how a current diesel moves its fuel, and so the protection matters for more, not less.
"It starts, it drives, so no harm done" — the myth that catches more people than any other. A petrol engine fed diesel normally will not run, 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 does; meanwhile your pump grinds. Fine and running are not the same at all.
Myth: a two-stroke additive makes it safe to drive home. It is an old workaround, meant for another problem. It does not put back what petrol has weakened, and the petrol is still inside your tank later.
If the motor has run, part of that petrol is in your filter and your lines, not your tank — and the next start pulls it straight back through your pump. So the myth "drain that tank yourself and you are sorted" does not hold. Besides, petrol drained into a can by the road 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 slides into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol vehicle at all. So the mistake runs one way.
It takes place when habit and your car stop matching. A car that is new to you — a hire car, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the drive. A well-known forecourt with the pumps in a different order. Fuelling up in a rush on the way to Bath Spa, with a train to catch. Exactly the moment it happens: after years of driving petrol, someone fills a diesel Renault Megane for the first time. Add rain, a phone call or a back seat full of kids, and your hand does what it has always done.
Perrymead people: how to avoid petrol in a diesel next time
- Not every forecourt in the UK keeps to green for unleaded and black for diesel, though most usually do. Read the pump's label; the colour is just a clue.
- Many cars state the fuel type inside the filler flap or on the cap, and so check there on your first fill in a vehicle you do not know.
- Label your key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- It seems silly and it does the trick: on your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the pump.
- Mistakes like this are straightforward to make whilst your mind is on something else, and so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and aftermarket devices are available for the remainder. Treat it as a safety net, and keep checking the pump.
- Less petrol makes a weaker mixture, and so stop the moment you notice — though remembering that your next step is unchanged. It is still not to fire it up.
Already put petrol in a diesel around Perrymead?
Then, there's only a short order of things. Do not start the vehicle, and don't switch the ignition on. If you are still on the forecourt — Esso or anywhere else — ask the attendants to help you roll the vehicle away from the pump. Then phone 0333 366 0103 and tell us what got in, roughly how much, and if it's run.
Corrosion and deposits form the issue with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Perrymead page.
One petrol in a diesel task around Perrymead costs more than another. Why?
A fair single quote does not exist here: four scenarios, four separate tasks. Mostly, the cost moves with which one you are in. Where the vehicle is matters too, and whether a technician can safely reach it, after the proportion of petrol to what the tank takes.
That's why our engineers ask three queries before costing rather than after: what went in, how much, and whether it's run. With the answers, there is a straight figure instead of a range.
About Perrymead itself
Perrymead is a suburban area situated on the outskirts of Bath, near the banks of the River Avon, and is characterised by its lakeside setting. Perrymead has a relatively low elevation of 76 metres and is located close to nearby places such as Lyncombe Vale and Widcombe. Perrymead is predominantly composed of detached housing and is home to a population of approximately 1542 residents. Perrymead is also conveniently located near Lyncombe Hill, offering scenic views of the surrounding area.
Fuel drain cover around Perrymead and across Somerset
Our teams answering petrol in diesel jobs in Perrymead, in the BA postcode area, also work the places around it, Lyncombe Vale, Widcombe and Lyncombe Hill among them. Our technicians drain where your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
Perrymead: still at the petrol pump?
In that case, you couldn't be in a better spot. Switched off it stays; then ring.