Hetton Downs: Petrol in a Diesel Car? How Worried to Be
Likely less than you are now — as long as no one has started it. "Have I ruined it?" is the first thing anyone in Hetton Downs asks, and the truthful answer is generally no, because petrol left in a diesel tank harms nothing until it's dragged through the fuel system — by ignition priming, by your starter, or by driving. Keep it like that: leave the engine off then call Petrol in Diesel. The remainder of this page sets out what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you a second time.
The motor and petrol in a diesel: what happens
Two jobs fall to diesel on its route round a motor. Before it combusts, it lubricates — and then it combusts. The high-pressure fuel pump and your injectors are built to very fine clearances, and the diesel passing through them is what keeps those surfaces from wearing down against one another.
Petrol does the first task badly and the second not at all. Being less viscous than diesel, petrol strips away the lubrication a fuel system needs, so a pump running on the blend to wear itself. It's also made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the clattering.
The shape of the issue is clear once you put those together. The harm is done by circulation, not by contact. All a tank with petrol in it amounts to is a fuel fault. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds moves on with the fuel to the injectors downstream.
Four scenarios our technicians see in Hetton Downs: how bad is petrol in a diesel?
Fuelled up, not once started. The best case there is. Being on a forecourt is what makes this the case: elsewhere, the vehicle has been driven there to begin with. With the petrol held inside the tank alone, it is cleared and rinsed right where it stands, and nothing more is needed.
Your ignition switched on, or a short start. Once primed, the fuel system has pulled petrol out of the tank as far as your filter and the lines. That is usually still an easy task — a drain, a flush, and the fuel filter dealt with.
Those few miles driven meant your pump labouring on fuel thinned by petrol throughout. The work is that tank, your lines, the filter and fresh fuel through the entire circuit, and how hard your car was driven counts as much as how far. Driving the children to Eppleton Academy Primary School is one kind of trip. Any miles on the A1(M), under 3 miles from Hetton Downs, means the motor has worked hard throughout, and a run to Sunderland, under 10 miles away, is a very different task as well.
Driven until it complained. Clattering, a lumpy idle, smoke, a throttle that has gone soft. The motor is telling you the fuel is no longer acting like diesel. Pull up on the spot — on the verge on Regent Street, at the kerb, down a side road — and do not move it. The drain and flush still come first, and they take care of it: when a car is stopped quickly, long-term damage is very rare.
What Hetton Downs 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 will be fine." It will not. Topping up removes nothing; it gives you a fuller tank of the same mixture. Percentage isn't how a diesel fuel system tolerates petrol, whatever that guidance assumes.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. A current diesel runs its fuel through more precise parts at higher pressure, which makes the lubrication matter more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no harm done." Feed diesel to a petrol engine and it normally won't run, so the motorist stops — and the harm stops with them. A diesel fed petrol normally starts, ticks over and drives away as if nothing has happened, whilst the pump wears. Fine and running are not the same at all.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a separate issue. None of what petrol weakened is put back by it — and later, your tank still holds that petrol.
If the motor has been run, part of the petrol sits in the fuel filter and your lines, not that tank — and the next start pulls it straight back through your pump. So the myth "drain your tank yourself and you're sorted" does not stand up. And, a can of petrol drained at the kerbside is genuinely hazardous.
How does petrol in a diesel happen?
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the slimmer of the two and slides into a diesel filler with almost no resistance; a diesel nozzle generally won't go into a petrol car at all. The forecourt makes it simple, and the error runs one way.
The moment routine stops matching the vehicle is the moment it occurs. A vehicle that's new to you — a hire car, on loan as a courtesy car, or brand new. Two vehicles on one drive, one petrol, one diesel. A forecourt you know, but with its pumps arranged differently. Filling up in a hurry on the way to Seaham, with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist accustomed to petrol: precisely when it takes place. Add rain, a phone call or a back seat full of children, and the hand repeats what it has always done.
How to avoid petrol in a diesel at your next fill-up in Hetton Downs
- Green for unleaded and black for diesel is usual in the UK — yet not on every forecourt. Trust the label on the petrol pump, not the colour.
- Check the filler flap. Many cars state the fuel type inside the flap or on the cap. Look at it on the first fill in a vehicle you don't know.
- A coloured fob or a sticker on the diesel's key achieves more than any amount of meaning to remember, in a house with one of each.
- It sounds daft and it works: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- While you are thinking about something else, this is an easy mistake to make — so tuck the phone away.
- Add-on devices exist for motors without one, and some diesels are built with a filler that won't take a petrol nozzle. Helpful — but a safety net at best, never a reason to stop checking the label.
- As soon as you notice, stop: less petrol inside the tank makes a weaker blend. What to do next does not change, though — still do not start it.
Put petrol in a diesel in Hetton Downs already?
Then the order of things is short. Do not switch your ignition on, and don't start it. If you are still on the forecourt — Tesco or anywhere else — ask the staff to help you push the vehicle clear of the pump. Then phone 0333 366 0103 and tell us what was put in, roughly how much, and if it's run.
Corrosion and deposits are the problem with AdBlue, where petrol means lost lubrication. So if it was AdBlue, say so — and see its own Hetton Downs page.
One petrol in a diesel task in Hetton Downs costs more than another. Why?
Four different tasks lie behind the four situations above — which is why there is no fair single price. The situation itself does most of the work of moving your cost. The share matters next, meaning how much of your tank is petrol, and then the position of the car and whether reaching it is safe for a technician.
What was put in, how much, and if it's run — three questions our technicians ask before costing, not after, for exactly that reason. Their replies are what change a range into one firm number.
About Hetton Downs itself
Hetton Downs is a suburban area situated near the River Wear in Tyne and Wear, with a mix of terraced housing and local amenities. Hetton Downs has a population of around 4833 people and is located approximately 5.9 miles from Sunderland. Hetton Downs sits at an elevation of 91 metres, overlooking the surrounding countryside. Hetton Downs is close to nearby places such as Hetton-le-Hole and Great Eppleton.
Fuel drain cover across Tyne and Wear, Hetton Downs included
Hetton-le-Hole, Broom Hill and Great Eppleton are among the places near Hetton Downs that the same vans work, answering petrol in diesel jobs across Hetton Downs's DH postcode area. A forecourt, a supermarket car park, a lay-by or your own driveway are all places our technicians drain, and the vehicle doesn't need to move to us.
In Hetton Downs and still at the petrol pump?
Nothing beats it: that is where you are. Keep it off. Phone.