Petrol in a Diesel Car in Deans: How Worried Should You Be?
Not started? Then less worried than you likely are. Till the ignition primes your pump, your starter cranks, or the vehicle is driven, petrol in a diesel tank simply waits there and does no harm. Which means the honest reply to that first Deans question — "have I ruined it?" — usually no. Keep it like that: leave the motor off and call Petrol in Diesel. 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.
What petrol in a diesel does to the engine
Two jobs fall to diesel on its journey round a motor. It lubricates to begin with, and only then does it burn. What stops the surfaces inside your high-pressure pump and your injectors from wearing against each other is the diesel passing through them — they are made to very fine clearances.
Petrol handles the first task poorly and the second not at all. It is thinner than diesel and strips away the protection the fuel system rests on, and so a pump running on a petrol blend is a pump wearing itself. And petrol is designed to resist igniting under compression, which is the opposite of what a diesel needs from its fuel. That's where the clattering comes from.
Together, those leave the shape of the trouble plain. It's circulation that does the harm, not contact. Petrol in the tank is a fuel problem. Once the pump has been running on that petrol, a mechanical problem has begun: whatever is shed by a pump that's wearing travels downstream to the injectors with the fuel.
How bad is petrol in a diesel? Four situations our technicians see in Deans
Filled but never started — the best it gets. That petrol is inside that tank and just your tank, and the task is a drain and a flush where the car sits. This is the one scenario that can only truly happen on a forecourt, since anywhere else the car has been driven to get there.
The ignition turned on, or a brief start. Your system has been primed, so petrol has left your tank and got to your filter and your lines. Still generally simple: drain, flush, and your filter seen to.
Those few miles on the road were the pump working on fuel diluted by petrol throughout. Miles is only half of that; how hard it was driven matters just as much. Either way the work runs to that tank, the fuel lines, your filter and clean fuel through the whole system. A school run to St Peter's CofE Primary School is one matter. A run as far as Salford, under 3 miles away, is a very different job. So is any miles on the M61, under a mile from Deans, where your engine has been running hard the whole time.
It complained, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone uneven. What you are hearing is your motor reporting fuel that no longer behaves like diesel. Leave it where it stops: a lay-by, a side street, the verge on St Peter's Road. A car stopped soon very seldom has lasting damage, because the fuel drain and the flush, which still go first, deal with it.
Stories Deans drivers hear about petrol in a diesel
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing is removed by topping up — you are left with a fuller tank, still the same mix. That guidance assumes a diesel fuel system handles petrol by percentage. It doesn't.
Not so: a newer diesel copes with a bit of petrol. If anything, the opposite. Lubrication counts more on newer diesels, not less, because their fuel passes through more precise parts at higher pressure.
"It starts, it drives, and so there is no harm" — the myth that catches more drivers than any other. Diesel in a petrol motor normally leaves a motor that will not run: the motorist stops, and so does the damage. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump wears. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a different issue. None of what petrol weakened is put back by it — and later, that tank still contains the petrol.
Once your engine has run, part of that petrol sits in the fuel filter and the fuel lines, not that tank — and your next start pulls it straight back through the pump. So the myth "drain that tank yourself and you're sorted" doesn't hold. And, a can of petrol drained by the kerbside is truly risky.
Petrol in a diesel: how does it take place?
It's seldom carelessness, and nobody does it on purpose. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, while the diesel one generally won't fit a petrol vehicle. That's how the forecourt makes it straightforward.
It happens when routine and your car stop matching. A new car, a hire car or a courtesy car. One petrol and one diesel on the drive of the same household. The pumps in a different order on a well-known forecourt. Racing for a train at Swinton (Manchester) and fuelling up en route. Precisely the moment it occurs: after years of driving petrol, a driver fills a diesel Renault Megane for the first time. With rain, a call arriving, or children to deal with, your hand simply does what it has always done.
How to avoid petrol in a diesel on your next fill-up around Deans
- Check the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what matters.
- In a motor you don't know, look inside the flap over your filler or at the cap before the first fill: plenty of cars print the fuel type there.
- One of each in the house? Mark your key to your diesel — a coloured fob, a sticker — since meaning to remember is not enough.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump. It sounds daft and it works.
- Tuck the phone away. This is an easy mistake to make while you're thinking about something else.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler designed to reject a petrol nozzle, and add-on devices are available for the rest. Count it as a backstop, and keep checking the pump.
- As soon as you realise, stop: less petrol in that tank means a thinner mixture. What to do next does not change, though — still don't start it.
Deans: already put petrol in a diesel?
The order of things is brief, then. Starting it is out, and so is switching on the ignition. The attendants on the forecourt — whether at Shell itself or wherever you filled up — will usually help push it clear of the pump if you ask. Phone 0333 366 0103 next, with three facts — the fuel, the approximate amount, and whether it has run.
Say so if it was AdBlue instead of petrol: it's a separate problem, with its own page for Deans, because AdBlue brings corrosion and deposits rather than lost lubrication.
Why one petrol in a diesel job around Deans costs more than another
There's no honest single price for this, because the four scenarios above are four separate tasks. Which of them you are in is chiefly what moves the cost. Two things follow that: the petrol that went in as a share of what that tank holds, then the place your car is in and whether a van can reach it safely.
Three questions come first, before quoting, instead of after — what was put in, how much, has it run — and this is the reason. Those answers turn a range into a straight figure.
About Deans and its setting
Deans is a suburban area in Greater Manchester, situated approximately 2.8 miles from Salford and 166.8 miles from London. Deans lies inland at an elevation of around 60 metres, characterised by its predominantly semi-detached housing stock. Deans is located near other local areas such as Swinton, Newtown, and Light Bourne Green, and has a population of around 7545 residents.
Fuel drain cover across Greater Manchester, Deans included
Swinton, Newtown and Light Bourne Green are among the places near Deans that the same teams work, answering petrol in diesel jobs across Deans's M postcode area. We drain where your car is — your own drive, a lay-by, a supermarket car park, a forecourt — so it does not have to come to us.
At the petrol pump in Deans, still?
No position is better: that is where you now are. Switched off it remains; then ring.