Poolsbrook: Petrol in a Diesel Car? How Worried to Be
Not started? Then less anxious than you probably are. Till the ignition primes your pump, the starter turns, or the vehicle is driven, petrol in a diesel tank simply rests there and does nothing. Which means the honest reply to the first Poolsbrook question — "have I wrecked it?" — usually no. Petrol in Diesel is who to phone, with your motor left off, so it remains that way. The rest of this page covers what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you a second time.
Petrol in a diesel: what does it do to the motor?
Diesel does two jobs on its way through a motor. Before it burns, it lubricates — then it ignites. What keeps the surfaces inside the high-pressure fuel pump and the injectors from wearing down against one another is the diesel flowing through them — they are designed to extremely fine gaps.
Badly at the first, not at all at the second: that is petrol. A pump running on a petrol blend is wearing itself out, since petrol is runnier than diesel and takes away the lubrication your fuel system depends on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that is where the knocking comes.
Seen together, they show what shape the trouble takes. The damage is done by movement, not by contact. All a tank with petrol in it amounts to is a fuel issue. Whatever a worn pump sheds goes on, carried by your fuel, into your injectors further along, which is why a pump that has been working on the petrol is where a mechanical fault starts.
Petrol in a diesel around Poolsbrook: how bad is it? Four cases
The best case there is: filled up, not once started. Only the tank has petrol in it, and so the task is emptying your tank and cleaning your system where your car sits. This scenario can only really occur at a forecourt: anywhere else, the car got there by being driven.
A brief spell of running, or just the ignition on. Once primed, your system has drawn petrol from that tank up to the fuel filter and your lines. That is generally still a straightforward job — a drain, a flush, and your filter dealt with.
Those few miles driven meant the pump working on fuel diluted by petrol the whole way. How hard the car was driven matters as much as how far, and the work covers your tank, the fuel lines, the filter and clean fuel through the whole system. Short trips, like the school run to Poolsbrook Primary Academy, are one matter. Driving as far as Sheffield, under 15 miles away, makes a very different job — as does any miles on the M1, under a mile from Poolsbrook, with the engine working hard all the way.
Driven until it protested. Clattering, an uneven idle, smoke, a throttle that has gone soft. The fuel is not acting like diesel any more, and your engine is telling you. Whether it is the verge on The Grove, a lay-by or a side road, stop there then leave it. The drain and flush still go first, and they take care of it: if a car is stopped soon, long-term damage is very unusual.
Poolsbrook drivers and the petrol in a diesel stories they hear
"Top it up the rest of the way with diesel and it will be fine" — a myth. It won't. Nothing comes out when you top up — that tank just carries more of the same mixture. The assumption behind the guidance — that diesel fuel systems tolerate petrol by percentage — is wrong.
Myth: "A current diesel can cope with a bit of petrol." If anything, the reverse. A modern diesel sends its fuel through finer components at higher pressure, which makes the lubrication matter more, not less.
"It starts, it drives, and so no harm done" — the myth that trips up more motorists than any other. The driver of a petrol engine fed diesel usually stops, since it will not run, and the damage stops with them. A diesel fed petrol usually starts, ticks over and drives away as though nothing has happened, whilst your pump wears. Fine and running aren't the same thing.
Myth: "Add some two-stroke oil and drive the car home." It's an outdated workaround for a separate fault. The petrol is still in your tank after that, and whatever it has thinned isn't put back.
"Drain it yourself and you're sorted" — a myth, since after it's been running some petrol lies in the filter and lines, waiting to go right back through your pump on your next start. Besides, petrol cleared into a can by the road is genuinely dangerous.
How does petrol in a diesel happen?
It's seldom carelessness, and nobody does it on purpose. The petrol nozzle is the narrower of the two and slips into a diesel filler with almost no resistance; a diesel nozzle mostly won't go into a petrol vehicle at all. The forecourt makes it easy, and the mistake runs one way.
The moment habit stops matching the car is the moment it takes place. A new motor, a hire car or a courtesy car. Two vehicles on one drive, one petrol, one diesel. The pumps in a different order on a familiar forecourt. Filling up in a rush on the way to Chesterfield, with a train to catch. Years of petrol cars behind you, a diesel Renault Megane in front of you on the forecourt for its first tank — that is when. The hand repeats what it has always done when you add rain, a phone call or a back seat full of kids.
Poolsbrook drivers: how to avoid petrol in a diesel next time
- 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.
- Many vehicles state the fuel inside the filler flap or on the cap, and so check there on the first fill in any motor you don't know.
- Label the key. In a home with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Before the nozzle leaves the pump the first time you fuel a hired or new motor, say "diesel" aloud. Daft, perhaps, yet it works.
- Mistakes like this are straightforward to make while your mind is on something else, so your phone goes away.
- Some diesels come with a filler built to refuse a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop reading the petrol pump.
- The moment you notice, stop: less petrol in the tank means a weaker mix. What to do next does not change, though — still don't fire it up.
Poolsbrook: already put petrol in a diesel?
Then the order of things is short. Starting it is out, and so is switching on the ignition. Still at the forecourt, at Morrisons or anywhere else? Ask the attendants to help you roll it clear of the petrol pump. Then call 0333 366 0103 and tell us what got in, about how much, and whether it has run.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different fault — Poolsbrook has a page just for it.
What makes one Poolsbrook petrol in a diesel job cost more than the next
Four different tasks lie behind the four scenarios above — which is why there's no fair single price. Which of them you're in is mostly what shifts the cost. The proportion counts next, meaning how much of the tank is petrol, and then the position of your car and whether getting to it is safe for a technician.
What went in, how much, and if it has run — three questions our engineers ask before quoting, not after, for exactly that reason. A range turns into a straight figure when the replies are in.
About Poolsbrook itself
Poolsbrook is a small suburban area in Derbyshire, situated near the River Rother and close to the city of Sheffield. Poolsbrook has a relatively low elevation of 52 metres and is located near several other local places, including Netherthorpe, Woodthorpe, and Lowgates. Poolsbrook is characterized by its semi-detached housing and quiet residential atmosphere.
Across Derbyshire and around Poolsbrook: fuel drain cover
Our teams answering petrol in diesel calls around Poolsbrook, in the S postcode area, equally work the spots around it, Netherthorpe, Woodthorpe and Lowgates included. You need not move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all spots where we work.
Poolsbrook: still at the pump?
Then you're in the best place there is. Keep it off. Phone.