How Worried Should You Be? Petrol in a Diesel Car in Waingroves
Likely less than you already are — provided nobody has started it. Everyone around Waingroves starts with "have I ruined it?", and the fair answer is generally no: petrol left inside that tank of a diesel stays harmless until priming, cranking or driving draws it into your fuel system. Petrol in Diesel is who to ring, with your engine left off, and so it stays that way. The rest of this page explains what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you a second time.
Inside the motor: what petrol in a diesel really does
Two jobs fall to diesel on its route through a motor. Before it combusts, it protects — then it burns. Very fine tolerances are built into the fuel injectors and the high-pressure fuel pump, and just the diesel running through stops their surfaces grinding together.
The second job petrol does not do at all, and the first it does badly. It is thinner than diesel and removes the lubrication your fuel system rests 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 rattling comes from.
Taken together, they show the shape the issue has. Not contact but circulation is what does the harm. Any tank with petrol in it is a fuel issue. 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 your injectors beyond it.
Four situations we see in Waingroves: how bad is petrol in a diesel?
Filled up, not once started. The best case there can be. That petrol is in the tank and just that tank, and the job is a drain and a flush where your car sits. This is the one situation that can only truly take place on a forecourt, since anywhere else the vehicle has been driven to get there.
Started for a second, or just the ignition on. The fuel system has been bled, and so petrol has left your tank and got to the fuel filter and the lines. Normally little more than clearing, flushing and sorting the fuel filter, so still easy.
Your pump now worked a few miles on diluted fuel — that's what driving it does. Tank, lines, filter, then fresh fuel run through the whole circuit: that is the work, and the way the vehicle was driven counts as much as the mileage. On the school run to Waingroves Primary School, the distance is short. A run as far as Derby, under 10 miles away, is a very different job. So is any miles on the M1, under 5 miles from Waingroves, where your engine has been labouring hard throughout.
Driven till it complained. Knocking, a ragged idle, smoke, a throttle that has gone soft. The fuel isn't behaving like diesel any more, and the motor is saying so. Whether it's the verge on Jessop Street, a lay-by or a side road, stop there and leave it. The fuel drain and flush still go first, and they take care of it: when a vehicle is pulled over soon, long-term damage is very uncommon.
Waingroves motorists and that petrol in a diesel myths they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it'll be." Nothing is removed by topping up — you are left with a bigger tank, still the same mixture. Percentage is not how a diesel fuel system copes with petrol, whatever that advice assumes.
Not so: a current diesel copes with a bit of petrol. If anything, the reverse. A current diesel sends its fuel through smaller parts at higher pressure, which makes the lubrication matter more, not less.
One myth that catches people out: if it starts and drives, it must be unharmed. Any petrol engine fed diesel usually will not run, and so the driver stops and the damage stops with them. Feed petrol to a diesel and it generally fires up, idles and pulls away like nothing has happened — all the while its pump wears. Being able to run isn't the same as being fine.
Myth: "Add some two-stroke oil and drive the car home." It's an old fix for a separate fault. The petrol is still in the tank after that, and what it has thinned is not put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in your filter and lines, waiting to go right back through your pump at your next start. Besides, petrol emptied into a can by the road is truly risky.
Why petrol in a diesel occurs at all
No one does it on purpose, and it's rarely carelessness. A diesel nozzle generally will not fit a petrol motor, yet the slimmer petrol nozzle goes into the filler of a diesel almost without resistance — so forecourts make this one mistake easy, and only in that direction.
The moment habit stops matching the vehicle is the moment it happens. Hire cars, courtesy cars, and motors that are new to you. Households running one of each, petrol and diesel. A forecourt you know, only with its pumps laid out differently. A train to catch, and a hurried fill on the way to Langley Mill. Years of petrol motors behind you, a diesel Renault Clio in front of you at the forecourt for its first tank — that's when. The hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
Next time you fill up in Waingroves: preventing petrol in a diesel
- The label is what matters, and so check the petrol pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on every forecourt.
- Inspect your filler flap. Many motors state the fuel type inside the flap or on the cap. Look at it on your first fill in any motor you do not know.
- One of each in the house? Mark your key to the diesel — a coloured fob, a sticker — because meaning to remember isn't enough.
- "Diesel", out loud, before you pick up the nozzle — each time a new or hired car gets its first tank. It seems daft. It does the trick.
- Mistakes like this are simple to make whilst your mind is on something else, so your phone goes away.
- Some diesels have a filler built to refuse a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the petrol pump.
- Stop as soon as you notice. Less petrol in the tank makes a weaker blend. It does not change what to do next, which is still not to crank it.
Waingroves: already put petrol in a diesel?
Then the order of things is brief. Never start the vehicle, and do not turn the ignition on. Yet at the forecourt, at Sainsbury's or anywhere else? Ask the attendants to help you push it clear of the petrol pump. Ring 0333 366 0103 next, with three facts — your fuel, the approximate quantity, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different fault — Waingroves has a page just for it.
One petrol in a diesel job in Waingroves costs more than another. Why?
A fair single quote does not exist here: four situations, four separate jobs. What shifts your cost is chiefly which of them you are in. Where the vehicle is counts too, and whether a van can safely get to it, after the share of petrol to what your tank holds.
That's why our engineers ask three questions before costing rather than after: what was put in, how much, and if it has run. A range becomes a straight figure when those answers are in.
About Waingroves
Waingroves is a suburban area in Derbyshire, situated approximately 8.8 miles north of Derby, and is characterized by its semi-detached housing stock. Waingroves sits inland, at an elevation of around 139 metres, and is located near the communities of Peasehill, Codnor, and Codnor Gate. Waingroves has a population of around 3541 residents, and is positioned about 118.5 miles northwest of London.
Waingroves and Derbyshire: where our fuel drain cover reaches
Petrol in diesel call-outs around Waingroves — part of the DE postcode area — go to vans that likewise cover the spots around it, Peasehill, Codnor and Codnor Gate included. A forecourt, a supermarket car park, a lay-by or your own driveway are all spots we drain, and your car does not need to come to us.
At the petrol pump in Waingroves, right now?
Then you are in the best place there can be. Keep it off. Phone.