Petrol in a Diesel Car in Marks Gate: How Worried Should You Be?
Not started? Then less anxious than you probably feel. Until your ignition primes your pump, the starter cranks, or your vehicle is driven, petrol in a diesel tank just sits there and does nothing. Which makes the honest reply to that first Marks Gate question — "have I wrecked it?" — normally no. Keep it like that: leave the engine off and phone Petrol in Diesel. The rest of this page explains what petrol really does to a diesel, how to judge how far it has got, and how to make sure it does not happen to you again.
Inside the motor: what petrol in a diesel does
Two tasks fall to diesel on its journey round a motor. It burns, and before it burns it protects. Designed to very fine tolerances, the injectors and the pump rely on the diesel flowing through them to stop their surfaces wearing against one another.
Of those two jobs, petrol manages the first badly and the second never. The clattering comes from petrol being designed not to ignite when compressed, which is exactly the opposite of what a diesel needs. On top of that it is thinner than diesel, it strips away the lubrication the fuel system hinges on, and any pump working on that blend is wearing itself.
Together, those make the shape of the issue clear. Contact doesn't do the harm — movement does. Any tank with petrol in it is a fuel issue. A pump that has been working on that petrol is the start of a mechanical one, and whatever a worn pump sheds travels on with the fuel to the fuel injectors further on.
How bad is petrol in a diesel? Four situations our engineers see around Marks Gate
Filled but never started — as good as it gets. Being at a forecourt is what makes this possible: elsewhere, your car has been driven there to begin with. With the petrol held inside the tank alone, it is drained and cleaned right where it stands, and nothing more is needed.
A moment's running, or merely your ignition on. Petrol has come out of that tank and got to the filter and the fuel lines, since your system has been primed. Normally nothing more than emptying, purging and sorting your filter, and so still simple.
Some miles driven, and your pump has spent each of them running on thinned fuel. Distance is only half of it; how hard it was driven matters just as much. Either way this work runs to the tank, your lines, your filter and clean fuel through the entire circuit. Driving the children to Crownfield Junior School is one sort of trip. A run as far as London, under 15 miles away, is a very different job. So is any miles on the M11, under 5 miles from Marks Gate, where your engine has been running hard the whole time.
It protested, and only then stopped: smoke, clattering, a throttle gone soft, an idle gone ragged. The engine is telling you the fuel is no longer behaving like diesel. Stop wherever you are — the verge on Collier Row Road, a lay-by, a side street — and leave the vehicle there. What goes first is still the drain and flush, and that deals with it, with long-term damage very rare when a car is pulled over quickly.
Myths Marks Gate drivers hear about petrol in a diesel
Myth: topping up to full with diesel makes it fine. It doesn't. Nothing comes out when you top up — that tank simply carries more of the same mixture. A diesel fuel system does not accept petrol by percentage in the way that guidance presumes.
Myth: a current diesel copes with a bit of petrol. Rather, the reverse. Protection matters more on current diesels, not less, because their fuel passes through more precise parts at higher pressure.
One myth that catches motorists out: if it starts and drives, it must be unharmed. Feed diesel to a petrol motor and it normally won't run, so the driver stops — and the damage stops with them. Feed petrol to a diesel and it usually fires up, ticks over and drives away as if nothing has happened — all while its pump is wearing. Fine and running are not the same thing.
"A drop of two-stroke oil and drive it home" — a myth, borrowed from a fix from years ago, for a separate issue. The petrol is still inside your tank afterwards, and what it has diluted is not put back.
Myth: "Drain that tank yourself and you are sorted." Once the motor has been run, some of the petrol is no longer in the tank: it is in your filter and the fuel lines, and it goes straight back through your pump at the next start. Emptying petrol into a can by the kerbside is also truly hazardous.
Petrol in a diesel: how does it occur?
On purpose? Never. Through carelessness? Seldom, if ever. The forecourt makes it easy: the petrol nozzle is the narrower of the two, and it slips into a diesel filler with almost no resistance, whilst a diesel nozzle generally won't go into a petrol motor at all. So the error runs one way.
It occurs when habit and your car stop matching. Any car that is new to you — hired, on loan as a courtesy car, or just bought. One petrol and one diesel on the drive of the same household. The pumps in a different order on a familiar forecourt. A rushed fill en route to Chadwell Heath with a train to catch. A new-to-you diesel Volkswagen Golf, its first fuelling, and a motorist used to petrol: precisely when it occurs. Your hand repeats what it has always done once you add rain, a phone call or a back seat full of kids.
Next time you fill up in Marks Gate: avoiding petrol in a diesel
- Check the petrol pump, not the colour. In the UK unleaded handles are normally green and diesel black, but not on each forecourt. The label is what matters.
- Inspect your filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on your first fill in any vehicle you do not know.
- Mark the key. In a house with one of each, a coloured fob or a sticker on the diesel's key does more than any amount of intending to remember.
- Say it before you lift it. On your first fill in a new or hired car, say "diesel" aloud before you take the nozzle off the petrol pump. It sounds daft and it works.
- While you're thinking about something else, this is an easy mistake to make — so tuck your phone away.
- Some diesels have a filler built to refuse a petrol nozzle, and devices you can add are available for vehicles without one. Such an inhibitor helps up to a point — as a safety net, not a reason to stop checking the petrol pump.
- Stop the moment you realise. Less petrol inside your tank makes a thinner blend. It does not change what to do next, which is still not to start the car.
Already put petrol in a diesel in Marks Gate?
Short and simple, then, is the order of things. Don't start the car, and don't turn the ignition on. Still at the forecourt, at Esso or anywhere else? Ask the attendants to help you push the car away from the pump. What was put in, roughly how much, and if it has run: tell us those when you call 0333 366 0103.
AdBlue, not petrol? Then tell us. Corrosion and deposits, not lost protection, make it a different issue — Marks Gate has a page just for it.
What makes one Marks Gate petrol in a diesel job cost more than the next
The four situations above are four separate tasks, so no single price for this would be honest. Chiefly, your cost moves with which situation you are in. Where the car is counts too, and whether our van can safely reach it, after the ratio of petrol to what your tank takes.
That's why our engineers ask three queries before pricing rather than after: what was put in, how much, and if it has run. Those replies change a range into a straight figure.
About Marks Gate
Marks Gate is a small suburban area in Greater London, situated near the River Roding at an elevation of 39 metres. Marks Gate lies on the northeastern edge of London, approximately 13 miles from the city centre. Marks Gate is characterised by its terraced housing and proximity to nearby places such as Collier Row and Little Heath. Marks Gate is a relatively small community with a population of around 773 residents.
Marks Gate and Greater London: where our fuel drain cover runs
Petrol in diesel call-outs around Marks Gate — part of the RM postcode area — go to vans that likewise cover the locations round it, Collier Row, Alderwood Terrace and Little Heath among them. The car doesn't need to move to us: our technicians drain at a forecourt, in a supermarket car park, in a lay-by or on your own drive.
In Marks Gate and still at the petrol pump?
Then, you couldn't be in a better spot. Ring, and leave it turned off.