How Worried Should You Be? Petrol in a Diesel Car in New Haw
Likely less than you already are — as long as nobody has started the vehicle. "Have I ruined it?" is the first thing anyone around New Haw asks, and the honest answer is generally no, because petrol resting in a diesel tank hurts nothing till it is drawn through your fuel system — by ignition priming, by your starter, or by driving. Leave the motor off then ring Petrol in Diesel — that keeps it that way. The rest of this page sets out what petrol actually does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
Inside the motor: what petrol in a diesel does
Two tasks fall to diesel on its journey round a motor. It combusts, and before it ignites it lubricates. The high-pressure fuel pump and your injectors are built to very fine gaps, and your diesel passing through them is what stops those surfaces from grinding against each other.
Petrol does the first task poorly and the second not at all. The rattling comes from petrol being designed not to ignite when compressed, which is exactly the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication the system depends on, and any pump working on such a blend is wearing itself.
The shape of the issue is plain once you put those together. Not contact but movement is what does the damage. Petrol in the tank is a fuel problem. A pump that has been labouring on that petrol is the start of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors downstream.
How bad is petrol in a diesel? Four situations our engineers see in New Haw
Filled up, and never started: nothing beats it. Being on a forecourt is what makes this possible: elsewhere, the car has been driven there to begin with. With the petrol held in that tank alone, it is cleared and cleaned on the spot, and nothing more is needed.
Started for a second, or just the ignition on. Petrol has come out of that tank and reached your filter and your lines, because the fuel system has been primed. Drain, flush, see to the filter: still usually easy.
A couple of miles driven, and your pump has spent every one of them running on diluted fuel. The work is the tank, the lines, the filter and clean fuel through the whole system, and how hard the vehicle was driven counts as much as how far. Short trips, like the school run to The Grange Community Infant School, are one thing. Very different once more: a trip to Westminster, under 25 miles away, or any miles on the M25, under a mile from New Haw, where the engine never stopped labouring hard.
Rattling, an uneven idle, smoke, a throttle gone soft: driven until it complained. The motor is telling you the fuel is no longer behaving like diesel. Whether it is the verge on Woodham Lane, a lay-by or a side street, stop where you are and leave it. The drain and flush-through still come first, and they sort it out: if a vehicle is pulled over quickly, permanent damage is very unusual.
Petrol in a diesel stories New Haw drivers hear
Myth: topping up to full with diesel makes it fine. It doesn't. A bigger tank of the same mix is all it gives, since topping up takes out nothing. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Not so: a current diesel copes with a bit of petrol. Rather, the reverse. A current diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
This is the one that catches people. Myth: "If it starts and drives, there is no damage done." Feed diesel to a petrol motor and it normally won't run, and so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it normally fires up, ticks over and pulls away like nothing has happened — all while its pump is wearing. Fine and running aren't the same thing.
An old fix for a distinct issue lies behind this one. Myth: "Add some two-stroke oil and drive the car home." None of what petrol weakened is put back by it — and later, the tank still holds that petrol.
Myth: "Drain that tank yourself and you are sorted." Once the engine has run, some of that petrol is no longer inside your tank: it's in the filter and the lines, and it goes straight back through the pump on the next start. Besides, petrol cleared into a can by the road is genuinely hazardous.
How petrol ends up: petrol in a diesel
It is seldom carelessness, and nobody does it on purpose. A diesel nozzle generally won't go into a petrol vehicle, but the smaller petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake simple, and only in that direction.
Habit and your car falling out of step is when it takes place. Hire cars, courtesy cars, and cars that are new to you. One petrol and one diesel on the driveway of the same household. A forecourt you know, only with its pumps arranged differently. A rushed fill on the way to West Byfleet with a train to catch. The first fill-up in a diesel BMW 3 Series after years of driving petrol is exactly the moment it takes place. The hand does what it has always done when you add rain, a phone call or a back seat full of kids.
New Haw motorists: how to prevent petrol in a diesel next time
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, yet not on every forecourt. The label is what counts.
- The first fill in a strange vehicle is the time to check the filler flap — inside it, or on the cap, plenty of vehicles state the fuel to use.
- A coloured fob or a sticker on your diesel's key does more than any amount of intending to remember, for a household with one of each.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car gets its first tank. It seems silly. It works.
- Tuck the phone away. This is an easy mistake to make whilst you are thinking about something else.
- Some diesels have a filler built to refuse a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- The moment you notice, stop: less petrol in your tank means a thinner mix. What to do next doesn't change, though — still do not crank it.
Petrol already in a diesel around New Haw? Begin here
In that case, there is only a short order of things. Don't switch the ignition on, and do not start it. Still on the forecourt, at Esso or anywhere else? Ask the attendants to help you push the car clear of the pump. Then ring 0333 366 0103 and tell us what went in, roughly how much, and if it has run.
Say so if it was AdBlue rather than petrol: it is a different problem, with its own page for New Haw, since AdBlue brings corrosion and deposits rather than lost lubrication.
New Haw petrol in a diesel tasks: why one costs more than another
Four different jobs sit behind the four situations above — which is why there is no honest single quote. What shifts the cost is chiefly which of them you're in. Beyond that it is the share — how much petrol was put in against how much your tank holds — and then where your car is and whether a technician can reach it safely.
Three questions come first, before quoting, instead of after — what was put in, how much, has it run — and that is the reason. Given the replies, you get a straight figure instead of a range.
About New Haw
New Haw is a village in Surrey, situated on the riverside at a low elevation of around 22 metres. New Haw lies near the towns of West Byfleet and Woodham, and is part of the larger commuter belt around London. New Haw has a population of approximately 4310 people, predominantly living in semi-detached housing. New Haw is also close to Row Town and other nearby settlements.
Across Surrey and around New Haw: fuel drain cover
Petrol in diesel call-outs around New Haw — part of the KT postcode area — go to vans that also cover the spots around it, Woodham, West Byfleet and Row Town included. A forecourt, a supermarket car park, a lay-by or your own driveway are all places we drain, and the vehicle doesn't need to move to us.
In New Haw and still at the petrol pump?
No position is better: that is where you now are. Keep it off. Phone.