Pitses: Petrol in a Diesel Car? How Worried to Be
Likely less than you are now — as long as no one has started it. Petrol sitting in a diesel tank does nothing to the motor until something pulls it through your fuel system — your ignition priming your pump, your starter, or the drive on its own. So the honest answer to the first question everyone around Pitses asks, "have I ruined it?", is normally no. Leave your motor off and ring Petrol in Diesel — that is how you keep it like that. Further down, this page sets out what petrol really does inside a diesel, how far it may have gone, and how to stop it happening to you again.
The motor and petrol in a diesel: what goes on
Passing through a motor, diesel does two things at the same time. Before it burns, it lubricates — and then it burns. Extremely fine gaps are built into the injectors and the high-pressure fuel pump, and only the diesel flowing through keeps those surfaces from grinding together.
The second job petrol does not do at all, and the first it does poorly. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, so a pump running on that mixture to wear itself. It is equally made to resist igniting under compression — the opposite of what a diesel needs — which is where you hear the knocking.
Put those together and the shape of the problem is plain. It is circulation that does the damage, not contact. Petrol in the tank is a fuel problem. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds moves on with your fuel to the fuel injectors further on.
Four situations our engineers see in Pitses: how serious is petrol in a diesel?
Fuelled, and not started: no case is better. The petrol is in that tank and only your tank, and the job is a drain and a flush where the vehicle sits. This is the one situation that can only truly occur on a forecourt, because anywhere else the vehicle has been driven to get there.
Ignition on, or started for a second. Once primed, the system has drawn petrol from the tank up to the fuel filter and the fuel lines. Usually little more than clearing, flushing and seeing to the fuel filter, and so still straightforward.
Driven a couple of miles. Now your pump has spent those miles running on thinned fuel. How hard your car was driven counts as much as how far, and this work covers your tank, the fuel lines, the filter and fresh fuel through the entire system. Short trips, like the school run to Alt Academy, are one thing. Very different once more: a run to Manchester, under 10 miles away, or some miles on the M60, under 3 miles from Pitses, where the engine never stopped running hard.
Knocking, a lumpy idle, smoke, a throttle gone soft: driven till it complained. The fuel isn't acting like diesel any more, and the engine is saying so. Stop on the spot — on the verge on Waltham Street, at the kerb, down a side road — and do not move it. What goes first is still the drain and flush, and that deals with it, with lasting damage very unusual if a vehicle is pulled over soon.
Pitses motorists and that petrol in a diesel stories they hear
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing is removed when you top up — that tank simply carries more of the same blend. Percentage is not how a diesel fuel system copes with petrol, however much that guidance assumes.
"Newer diesels can handle a little petrol" — a myth, and nearer the reverse. A modern diesel sends its fuel through finer components at higher pressure, which makes the lubrication count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no damage done." The driver of a petrol engine fed diesel normally stops, since it will not run, and the damage stops with them. Feed petrol to a diesel and it normally fires up, idles and drives away like nothing happened — all the while its pump wears. Fine and running are not the same at all.
Myth: a two-stroke additive lets you to drive home. It was an old workaround, supposed for another issue. It does not put back what petrol has diluted, and that petrol is still inside your tank afterwards.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol sits in the fuel filter and lines, ready to go straight back through your pump at your next start. Draining petrol into a can at the roadside is also really dangerous.
How it happens: petrol in a diesel
Carelessness is seldom the cause, and nobody means to do it. One way only, since of the nozzles: the narrower petrol one slides inside a diesel filler with almost no resistance, while the diesel one generally will not fit a petrol car. That is how the forecourt makes it straightforward.
Routine and your car falling out of step is when it occurs. A new car, a hire car or a courtesy car. Households running one of each, petrol and diesel. A familiar forecourt with the pumps in a different order. A hurried fill on the way to Mossley (Manchester) with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Passat in front of you on the forecourt for its first tank — that's when. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
How to avoid petrol in a diesel on your next fill-up in Pitses
- Read the pump, not the colour. In the UK unleaded handles are usually green and diesel black, but not on every forecourt. The label is what counts.
- The first fill in an unfamiliar motor is the time to check your filler flap — inside it, or on the cap, many cars state which fuel they take.
- A coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember, in a household with one of each.
- Before the nozzle comes off the petrol pump the first time you fuel a hired or new motor, say "diesel" out loud. Daft, yes, yet it works.
- Mistakes like this are simple to make while your mind is on something else, and so the phone goes away.
- Add-on devices exist for cars without one, and some diesels are built with a filler that won't accept a petrol nozzle. Useful — but a backstop at best, never a reason to stop checking the label.
- Spotting it mid-fill? Stop there and then. A thinner blend results from less petrol inside your tank, but your next step stays the same: don't fire it up.
Pitses: already put petrol in a diesel?
In that case, there's only a short order of things. Do not turn your ignition on, and don't start it. If you are still on the forecourt — Gulf or anywhere else — ask the attendants to help you push the car clear of the pump. Phone 0333 366 0103 next, with three answers — your fuel, the approximate volume, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost protection, make it a separate fault — Pitses has a page all for it.
What makes one Pitses petrol in a diesel job cost more than the next
A fair single price does not exist here: four situations, four separate jobs. Chiefly, your cost moves with which one you are in. Two things come after that: the petrol that got in as a share of what the tank holds, then the spot the vehicle is in and whether our van can reach it safely.
That is why our engineers ask three queries before costing rather than after: what was put in, how much, and if it has run. Those answers are what turn a range into one firm number.
About Pitses, for a moment
Pitses is a suburban area in Greater Manchester, situated near the riverside and approximately 7.4 miles from Manchester. Pitses has a population of around 5071 people and is characterised by semi-detached housing. Pitses sits at an elevation of 177 metres, overlooking the surrounding landscape. Pitses is close to nearby places such as Glodwick Lows, Alt, and Fenny Hill.
Pitses and Greater Manchester: where our fuel drain cover runs
Petrol in diesel jobs around Pitses — part of the OL postcode area — go to teams that also cover the places about it, Glodwick Lows, Alt and Fenny Hill among them. A forecourt, a supermarket car park, a lay-by or your own drive are all locations our engineers drain, and your car doesn't need to come to us.
At the pump in Pitses, still?
The best spot there is, then — that is where you are. Turned off it stays; then phone.