Redhills: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, provided it has not been started. Everyone in Redhills begins with "have I ruined it?", and the honest answer is usually no: petrol resting in the tank of a diesel stays harmless till priming, cranking or driving pulls it into your fuel system. Petrol in Diesel is who to call, with the engine left off, so it remains that way. Below, this page sets out what petrol really does inside a diesel, how far it might have got, and how to stop it happening to you again.
Petrol in a diesel: what does it do to the engine?
On its way through an engine, diesel does two jobs. It ignites, and before it combusts it lubricates. Extremely fine clearances go into your injectors and the high-pressure fuel pump, and only your diesel flowing through stops those surfaces grinding together.
Petrol handles the first job poorly and the second not at all. It is thinner than diesel and takes away the lubrication the system rests on, so a pump running on a petrol mixture 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 is where the rattling comes from.
Put these together and the shape of the trouble is clear. Not contact but circulation is what causes the damage. Petrol in the tank is a fuel fault. Once the pump has been running on that petrol, a mechanical problem has started: whatever is shed by a pump that's wearing is carried downstream to the injectors with the fuel.
Petrol in a diesel in Redhills: how bad is it? Four cases
Filled but not once started — as good as it gets. The petrol is in the tank and just that tank, and the task is a drain and a flush where the car sits. This is the one situation that can only really take place at a forecourt, since anywhere else your car has been driven to get there.
A moment's running, or just the ignition on. Your system has been bled, so petrol has left your tank and reached the fuel filter and your lines. Still usually easy: drain, flush, and the filter dealt with.
Driven a few miles. Now your pump has spent these miles running on weakened fuel. Miles is only half of it; how hard it was driven matters equally. Either way the work includes the tank, your lines, your filter and fresh fuel through the entire circuit. Driving the children to St Gabriel's CofE Primary School is one sort of trip. Very different again: a trip to Exeter, under 3 miles away, or some miles on the M5, under 5 miles from Redhills, where your engine kept working hard.
It protested, and only then stopped: smoke, rattling, a throttle gone soft, an idle gone ragged. That's the motor telling you its fuel no longer is behaving like diesel. Pull up where you are — on the verge on Redhills, at the kerb, down a side road — and do not move it. Lasting damage is very unusual if a vehicle is pulled over soon, and the drain and flush-through that still go first sort it out.
What Redhills people get told about petrol in a diesel — and the myths in it
It will not be fine. The myth: "Fill it the rest of the way with diesel and it will be." Nothing comes out when you top up — your tank just holds more of the same mixture. That guidance assumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A current diesel can cope with a bit of petrol." If anything, the opposite. A modern diesel sends its fuel through finer components at higher pressure, which makes the protection matter more, not less.
This is the one that fools people. Myth: "If it starts and drives, there is no harm done." Any petrol motor fed diesel normally will not run, so the motorist stops and the damage stops with them. Nothing looks to have happened when a diesel fed petrol fires up, ticks over and drives away, as it usually does; meanwhile the pump grinds. Being able to run isn't the same as being fine.
Myth: a two-stroke additive lets you to drive home. It was an old fix, meant for another fault. The petrol is still in that tank after that, and what it has diluted is not put back.
"Drain it yourself and you are sorted" — a myth, because after it's been running some petrol sits in your filter and lines, waiting to go right back through the pump on the next start. Clearing petrol into a can at the kerbside is also really dangerous.
Petrol in a diesel: how does it take place?
Nobody does it on purpose, and it is rarely carelessness. The petrol nozzle is the narrower of the two and slides 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 simple, and the slip runs one way.
When routine and the vehicle stop matching, it takes place. A car that is new to you — a hire car, on loan as a courtesy car, or just bought. Households running one of each, petrol and diesel. A well-known forecourt with the pumps in a different order. Fuelling up in a hurry on the way to Exeter St Davids, with a train to catch. The first fill-up in a diesel Volkswagen Golf after years of driving petrol is precisely the moment it happens. The hand does what it has always done once you add rain, a phone call or a back seat full of kids.
Preventing petrol in a diesel next time you fill up in Redhills
- Not every forecourt in the UK follows green for unleaded and black for diesel, even if most usually do. Check the petrol pump's label; the colour is only a clue.
- The first fill in a strange car is the time to check your filler flap — on it, or on the cap, plenty of cars state which fuel they take.
- Good intentions do less than a sticker or a fob in a bright colour on your diesel's key when a home has one of each. So mark it.
- It seems daft and it does the trick: on the first fill in a new or hired car, say "diesel" aloud before you lift the nozzle off the pump.
- Put your phone away. This is an easy mistake to make whilst you're thinking about something else.
- Some diesels have a filler designed to block a petrol nozzle, and devices you can add exist for vehicles without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop checking the petrol pump.
- Stop as soon as you notice. Less petrol inside the tank means a thinner mixture. It does not change what to do next, which is still not to start the vehicle.
Redhills: already put petrol in a diesel?
Short and simple, then, is the order of things. Do not start the vehicle, and do not turn the ignition on. If you're still at the forecourt — Esso or anywhere else — ask the attendants to help you push it away from the petrol pump. Next, 0333 366 0103. We'll ask what was put in, roughly how much, and if it's been run.
If it was AdBlue and not petrol, say so. That is a different problem — corrosion and deposits instead of lost protection — and it has its own page for Redhills.
Why one petrol in a diesel job in Redhills costs more than another
The four scenarios above are four separate jobs, so no single price for this would be fair. The scenario itself does most of the work of moving the cost. The proportion matters next, meaning how much of your tank is petrol, followed by the location of your car and whether reaching it is safe for our van.
What was put in, how much, and if it's run — three queries our technicians ask before pricing, not after, for exactly that reason. Given those answers, there is a straight figure instead of a range.
About Redhills
Redhills is a suburban area located on the outskirts of Exeter in Devon, sitting alongside the River Exe at an elevation of around 79 metres. Redhills is characterized by its semi-detached housing stock and is situated near other local neighbourhoods such as Foxhayes and Exwick. Redhills has a population of approximately 5478 residents and is close to the city centre of Exeter, being only 1.1 miles away. Redhills is also near Nadderwater, another nearby suburban area.
Fuel drain cover in Redhills and across Devon
Petrol in diesel calls around Redhills — part of the EX postcode area — go to teams that likewise cover the places around it, Foxhayes, Exwick and Nadderwater included. You need not move your car to us. Forecourts, supermarket car parks, lay-bys and your own driveway are all places we drain.
Redhills: still at the petrol pump?
Nothing beats it: that's where you now are. Turned off it remains; then phone.