How Worried Should You Be? Petrol in a Diesel Car in Mendlesham Green
Less than you likely are, provided it hasn't been started. Petrol sitting in a diesel tank does nothing to the motor till something draws it through the system — the ignition priming the pump, the starter, or driving itself. So the honest answer to the first query everyone around Mendlesham Green asks, "have I wrecked it?", is usually no. Keep it like that: leave the engine off and call Petrol in Diesel. What petrol really does to a diesel, how to judge how far it has gone, and how to stop it from happening a second time: that is the remainder of this page.
Petrol in a diesel: what does it do to the motor?
Diesel does two tasks on its way through an engine. It lubricates to begin with, and only then does it burn. The high-pressure fuel pump and the fuel injectors are built to very fine clearances, and the diesel passing through them is what stops those surfaces from grinding against each other.
Of these two jobs, petrol handles the first poorly and the second never. The knocking comes from petrol being made not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is runnier than diesel, it strips out the protection your system depends on, and any pump running on that mix is wearing itself.
The shape of the issue is clear once you put those together. Contact doesn't do the harm — movement does. Any tank with petrol in it is a fuel fault. The beginning of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to your injectors downstream.
Four situations our technicians see around Mendlesham Green: how serious is petrol in a diesel?
Fuelled, and not started: nothing beats it. The petrol is in the 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 on a forecourt, since anywhere else the car has been driven to get there.
A moment's running, or just your ignition on. Petrol has come out of the tank and got to the filter and the fuel lines, because your system has been primed. Normally little more than emptying, purging and seeing to the fuel filter, and so still straightforward.
Those few miles driven meant the pump running on fuel diluted by petrol the whole way. Mileage is only half of it; how hard it was driven counts equally. Either way this work runs to that tank, the lines, the filter and clean fuel through the whole system. A school run to Mendlesham Primary School is one matter. Very different once more: a trip to Colchester, under 25 miles away, or some mileage on the M11, under 50 miles from Mendlesham Green, where your engine never stopped running hard.
Driven on until it complained — rattling, smoke, a ragged idle, a dead throttle. The motor is telling you the fuel is no longer acting like diesel. Leave it wherever it stops: a lay-by, a side street, the verge on The Green. Permanent damage is very rare if a vehicle is pulled over quickly, and the drain and flush that still go first sort it out.
Petrol in a diesel stories Mendlesham Green drivers hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed when you top up — the tank simply carries more of the same blend. That guidance assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: a newer diesel copes with a bit of petrol. If anything, the opposite. A newer diesel sends its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
This is the one that fools people. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol engine and it usually will not run, so the motorist stops — and the harm stops with them. Feed petrol to a diesel and it generally fires up, idles and drives away as if nothing has happened — all the while its pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive the car home." It is an old workaround for a different issue. It doesn't put back what petrol has weakened, and the petrol is still in the tank later.
Myth: "Drain your tank yourself and you are sorted." Once the motor has run, some of the petrol is no longer in your tank: it is in your filter and the lines, and it goes right back through your pump on the next start. It is also really risky to drain petrol into a can by the roadside.
How does petrol in a diesel happen?
Carelessness is seldom the cause, and no one means to do it. The petrol nozzle is the slimmer of the two and slides 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 simple, and the error runs one way.
When habit and your car stop matching, it happens. A new vehicle, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. The pumps in a different order on a familiar forecourt. A rushed fill on the way to Stowmarket with a train to catch. Exactly the moment it takes place: after years of driving petrol, a driver fills a diesel Renault Clio for the first time. Throw in rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
How to avoid petrol in a diesel on your next fill-up around Mendlesham Green
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most generally do. Read the petrol pump's label; the colour is just a hint.
- In a motor you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of motors state the fuel type there.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key when a home has one of each. So label it.
- "Diesel", aloud, before you lift the nozzle — each time a new or hired car needs its first tank. It seems silly. It works.
- Thinking about something else is when this becomes an easy mistake to make, so put the phone away then keep your mind on the petrol pump.
- Some diesels have a filler designed to reject a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the pump.
- Spotting it mid-fill? Stop there and then. A thinner blend follows from less petrol inside that tank, yet the next step stays the same: don't start the vehicle.
Mendlesham Green: already put petrol in a diesel?
Short and simple, then, is the order of things. Don't turn the ignition on, and do not start it. Yet on the forecourt, at BP or anywhere else? Ask the staff to help you roll the car away from the petrol pump. Then ring 0333 366 0103 and tell us what went in, roughly how much, and whether it's run.
Say so if it was AdBlue rather than petrol: it's a different fault, with its own page for Mendlesham Green, since AdBlue brings corrosion and deposits instead of lost protection.
One petrol in a diesel task around Mendlesham Green costs more than another. Why?
An honest single quote does not exist here: four situations, four separate jobs. Mostly, the cost shifts with which situation you're in. Beyond that it is the ratio — how much petrol went in against how much that tank takes — and after that where the vehicle is and whether a technician can get to it safely.
Ahead of any quote, not after, come three queries: the fuel that was put in, the quantity, and whether it's run. That's why. Given those replies, there is a straight figure rather than a range.
About Mendlesham Green
Mendlesham Green is a small village in Suffolk, situated near the River Gipping and surrounded by rolling countryside. Mendlesham Green has a population of around 533 people and is characterized by its predominantly detached housing stock. Mendlesham Green sits at an elevation of 55 metres, close to nearby places such as Cay Hill and Middlewood Green. Mendlesham Green is located approximately 71 miles from London and 24 miles from Colchester, making it a rural community with access to larger urban centres.
Fuel drain cover across Suffolk, Mendlesham Green included
Petrol in diesel calls around Mendlesham Green — part of the IP postcode area — go to vans that likewise cover the places round it, Cay Hill, Tan Office and Middlewood Green among them. 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.
Mendlesham Green: still at the petrol pump?
Nothing beats it: that is where you are. Call, and keep it turned off.