Hey: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, provided it has not been started. Everyone in Hey starts with "have I ruined it?", and the honest answer is usually no: petrol resting in that tank of any diesel stays harmless until priming, cranking or driving draws it into your fuel system. To keep it that way, call Petrol in Diesel then leave the motor switched off. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
What petrol in a diesel does to the engine
Two jobs fall to diesel on its route round a motor. Lubricating comes before burning; it does both. What stops the surfaces inside the high-pressure fuel pump and your injectors from grinding against each other is your diesel passing through them — they are designed to extremely fine clearances.
Poorly at the first, not at all at the second: that's petrol. It is thinner than diesel and strips away the lubrication the system depends on, so a pump running on a petrol mixture is a pump wearing itself. And petrol is made to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That is where the knocking comes from.
The shape of the problem is plain once you put those together. Contact does not do the harm — circulation does. Where that petrol is only in the tank, it's a problem of fuel, nothing more. Whatever a worn pump sheds travels on, carried by the fuel, into the injectors further along, which is why a pump that has been working on that petrol is where a mechanical issue starts.
Hey, petrol in a diesel: four situations, from mild to significant
Filled up, and never started: no case is better. Just that tank has petrol in it, so the job is draining that tank and rinsing the system where the car stands. This situation can only truly take place on a forecourt: anywhere else, the vehicle got there by being driven.
Ignition on, or started for a second. With the fuel system primed, your lines and filter now hold petrol that came from your tank. Normally little more than clearing, flushing and sorting the filter, so still straightforward.
The pump now spent a couple of miles on weakened fuel — that is what driving the car does. Tank, lines, filter, then clean fuel run through the whole circuit: that is the work, and the way the vehicle was driven counts as much as the miles. Short trips, such as the school run to St Edwards Roman Catholic Primary, a Voluntary Academy, are one thing. Any miles on the Broadway, under 5 miles from Hey, means your engine working hard throughout, and a run to Manchester, under 10 miles away, is a very different job too.
Clattering, an uneven idle, smoke, a throttle gone soft: driven till it complained. The motor is telling you the fuel is no longer acting like diesel. Stop where you are — on the verge on Greaves Street, at the kerb, down a side road — and do not move it again. The drain and flush still go first, and they deal with it: when a car is pulled over soon, long-term damage is very unusual.
What Hey people get told about petrol in a diesel — and the stories in it
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. That advice presumes a diesel fuel system handles petrol by percentage. It doesn't.
"Newer diesels can handle a little petrol" — a myth, and closer to the reverse. At higher pressure, through finer parts: that is how a newer diesel moves its fuel, so the protection matters more, not less.
One myth that catches drivers out: if it starts and drives, it must be unharmed. The motorist of a petrol engine fed diesel usually has no choice but to stop, since it will not run, and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as though nothing has happened, while your pump wears. Being able to run is not the same as being fine.
Myth: a two-stroke additive makes it safe to drive home. It is an old fix, supposed for another problem. The petrol is still inside your tank after that, and what it has thinned isn't put back.
Myth: "Drain that tank yourself and you are sorted." Once the motor has run, some of that petrol is no longer in the tank: it is in the filter and your lines, and it goes straight back through your pump on your next start. On top of that, petrol cleared into a can by the road is truly risky.
How does petrol in a diesel occur?
It's seldom carelessness, and no one does it on purpose. A diesel nozzle mostly will not fit a petrol vehicle, yet the narrower petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake straightforward, and just in one direction.
The moment routine stops matching your car is the moment it happens. 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 laid out differently. Rushing for a train at Mossley (Manchester) and filling up en route. Years of petrol motors behind you, a diesel Renault Megane in front of you at the forecourt for its first tank — that is when. With rain, a call arriving, or children to deal with, your hand just does what it has always done.
Avoiding petrol in a diesel next time you fill up around Hey
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Check the petrol pump's label; the colour is only a hint.
- Many vehicles state the fuel type inside your filler flap or on the cap, and so check it on your first fill in a motor you don't know.
- One of each in the house? Label your key to your diesel — a bright fob, a sticker — because meaning to remember is not enough.
- Before the nozzle leaves the petrol pump the first time you fill a hired or new car, say "diesel" aloud. Daft, perhaps, but it works.
- Thinking about something else is when this becomes an easy mistake to make, and so tuck the phone away and keep your mind on the pump.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to refuse a petrol nozzle, and add-on devices are available for the rest. Count it as a backstop, then keep reading the pump.
- As soon as you notice, stop: less petrol inside the tank makes a thinner blend. What to do next doesn't change, though — still do not fire it up.
Hey: already put petrol in a diesel?
In that case, there is only a short order of things. Don't switch the ignition on, and don't crank it. Ask the staff to help you roll it away from the petrol pump if you're still on the forecourt, whether that is Gulf or anywhere else. What was put in, roughly how much, and if it has run: tell us those when you call 0333 366 0103.
Corrosion and deposits are the issue with AdBlue, where petrol means lost protection. So if it was AdBlue, say so — and see its own Hey page.
Why one petrol in a diesel task around Hey costs more than another
There's no fair single quote for this, since the four situations above are four different jobs. Which of them you are in is mostly what moves the cost. The proportion counts next, meaning how much of the tank is petrol, followed by the location of your car and whether reaching it is safe for our van.
Before any quote, not after, we ask three queries: your fuel that was put in, the volume, and if it's run. That's why. The replies turn a range into a straight figure.
About Hey itself
Hey is a suburban area in Greater Manchester, situated on the riverside and characterised by its terraced housing. Hey sits at an elevation of 196 metres, approximately 8.4 miles from Manchester, and is surrounded by nearby places such as Sun Hill, Lees, and Taylor Green. Hey is home to a population of around 7133 residents, who enjoy a relatively quiet location close to the city. Hey benefits from its proximity to Manchester, while also maintaining a distinct local identity.
Fuel drain cover across Greater Manchester, Hey included
Petrol in diesel calls around Hey — part of the OL postcode area — go to teams that also cover the spots about it, Sun Hill, Lees and Taylor Green among them. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and your vehicle does not need to come to us.
Still at the pump around Hey?
Nothing beats it: that is where you now are. Phone, and keep it switched off.