North Side: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, provided it has not been started. Everyone in North Side begins with "have I ruined it?", and the fair answer is usually no: petrol left inside that tank of a diesel remains harmless until priming, cranking or driving pulls it into your fuel system. Petrol in Diesel is who to phone, with the engine kept off, so it stays that way. Keep reading for three things: the effect petrol has inside a diesel engine, the clues of how far it has spread, and ways to make sure you don't do it again.
Petrol in a diesel: what does it do to the motor?
On its way through an engine, diesel does two jobs. It protects to begin with, and only then does it burn. Built to extremely fine tolerances, the fuel injectors and the pump depend on the diesel flowing through them to keep their surfaces from wearing against one another.
Of those two tasks, petrol manages the first badly and the second not at all. A pump working on a petrol mixture is wearing itself out, since petrol is runnier than diesel and strips out the lubrication your fuel system relies on. Petrol is also made to resist igniting under compression — the opposite of what a diesel wants from its fuel — and that's where the rattling comes.
Put those together and the shape of the problem is clear. Contact does not do the harm — movement does. Where the petrol is only inside that tank, it's an issue of fuel, nothing more. Whatever a worn pump sheds travels on, borne by the fuel, into the fuel injectors downstream, which is why a pump that has been working on that petrol is where a mechanical problem begins.
How bad is petrol in a diesel? Four situations we see in North Side
The best case there can be: filled up, never started. At a forecourt, and truly only there, the petrol is still limited to the tank — because anywhere else the car was driven to reach it. The task is draining and rinsing on the spot.
Started for a moment, or only your ignition on. Your system has been bled, so petrol has left the tank and got to your filter and the lines. Usually little more than clearing, cleaning and seeing to your filter, and so still easy.
A couple of miles driven, and the pump has spent each of them working on weakened fuel. Miles is only half of that; how hard it was driven counts equally. Either way the work runs to that tank, the fuel lines, the filter and fresh fuel through the whole circuit. Short trips, such as the school run to Northside Primary School, are one thing. Any mileage on the M6, under 50 miles from North Side, means the engine has worked hard throughout, and a run to Carlisle, under 50 miles away, is a very different job as well.
Driven until it complained. Knocking, a lumpy idle, smoke, a throttle that has gone soft. The fuel is not behaving like diesel any more, and the engine is telling you. Pull up where you are — on the verge on Burrow Walls, at the kerb, down a side road — and do not move it. Permanent damage is very unusual when a vehicle is pulled over early, and the drain and flush-through that still come first deal with it.
What North Side people get told about petrol in a diesel — and the myths in it
"Top it up the rest of the way with diesel and it will be fine" — a myth. It will not. A bigger tank of the same mix is all it gives, since topping up takes out nothing. That guidance supposes a diesel fuel system tolerates petrol by percentage. It does not.
Myth: "A modern diesel can cope with a bit of petrol." If anything, the opposite. Lubrication matters more on modern diesels, not less, because their fuel runs through finer parts at higher pressure.
The myth that catches drivers out: if it starts and drives, it must be unharmed. Any petrol engine fed diesel usually 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 wears. Running doesn't mean fine.
An outdated workaround for a distinct fault lies behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." It doesn't put back what petrol has thinned, and the petrol is still in that tank afterwards.
If your engine has run, part of the petrol sits in the fuel filter and the fuel lines, not the tank — and your next start pulls it straight back through your pump. So the myth "drain your tank yourself and you are sorted" doesn't hold. Draining petrol into a can by the kerbside is also really hazardous.
Petrol in a diesel: how does it happen?
It is seldom carelessness, and nobody does it on purpose. The forecourt makes it simple: the petrol nozzle is the slimmer of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle generally won't go into a petrol motor at all. So the slip runs one way.
When habit and your car stop matching, it occurs. Courtesy car, hire car, or a vehicle that's brand new. One petrol and one diesel on the driveway of the same household. A forecourt you know, but with its pumps arranged differently. A train to catch, and a rushed fill on the way to Workington. Years of petrol cars behind you, a diesel Renault Clio in front of you at the forecourt for its first tank — that is when. Throw in rain, a phone call or a back seat full of kids, and the hand repeats what it has always done.
North Side motorists: how to avoid petrol in a diesel next time
- A green handle for unleaded and black for diesel is normal in the UK — but not on every forecourt. Trust the label on the pump, not the colour.
- In a vehicle you don't know, look inside the flap over the filler or at the cap before your first fill: many cars state the fuel type there.
- Label your 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.
- It seems daft and it does the trick: on the first fill in a new or hired car, say "diesel" out loud before you take the nozzle off the petrol pump.
- Whilst you are thinking about something else, this is an easy mistake to make — so put the phone away.
- Some diesels have a filler built to block a petrol nozzle, and devices you can add are available for motors without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the pump.
- Spotting it mid-fill? Stop there and then. A thinner mix results from less petrol inside your tank, but your next stage remains the same: don't crank it.
Petrol already in a diesel around North Side? Start here
Short and simple, then, is the order of things. Leave it unstarted, with the ignition switched off too. Ask the staff to help you roll it clear of the petrol pump if you are still at the forecourt, whether that is Asda or somewhere else. Next, 0333 366 0103. We'll ask what was put in, about how much, and if it has been run.
If it was AdBlue instead of petrol, say so. That is a separate issue — corrosion and deposits instead of lost protection — and it has its own page for North Side.
North Side petrol in a diesel tasks: why one costs more than another
There is no fair single price for this, since the four situations above are four separate tasks. Chiefly, the cost moves with which situation you are in. Where the vehicle is counts too, and whether a van can safely get to it, after the ratio of petrol to what the tank holds.
What was put in, how much, and whether it's run — three questions our engineers ask before pricing, not after, for exactly that reason. Given those replies, there is a straight figure rather than a range.
About North Side, for a moment
North Side is a small suburban area located on the coast of Cumbria, with an elevation of around 20 metres above sea level. North Side sits near the towns of Workington and Barepot, and is close to the village of Siddick. North Side is characterized by its predominantly terraced housing stock, and is situated approximately 29 miles from the city of Carlisle.
Fuel drain cover across Cumbria, North Side included
Petrol in diesel calls around North Side — part of the CA postcode area — go to teams that also cover the locations round it, Workington, Barepot and Siddick included. A forecourt, a supermarket car park, a lay-by or your own drive are all places our engineers work, and your car does not need to move to us.
North Side: still at the pump?
Then, you could not be in a better spot. Leave the car switched off, and ring.