How Worried Should You Be? Petrol in a Diesel Car in Houston
Provided it has not been started, worry far less than you likely are. Petrol resting in a diesel tank does nothing to the motor till something draws it through the fuel system — your ignition priming the pump, the starter, or the drive on its own. So the fair answer to the first question anyone in Houston asks, "have I wrecked it?", is generally no. Petrol in Diesel is who to call, with your engine kept off, so it stays that way. What petrol really does to a diesel, how to judge how far it's travelled, and how to stop it from happening a second time: that is the remainder of this page.
What petrol in a diesel does to your engine
Passing through an engine, diesel does two things at once. It protects to begin with, and only then does it burn. Designed to very fine tolerances, the injectors and your pump depend on your diesel moving through them to stop their surfaces wearing against one another.
Of those two jobs, petrol handles the first badly and the second not at all. Being less viscous than diesel, petrol strips out the lubrication a fuel system needs, leaving a pump running on the blend wearing itself. It is equally made to resist igniting under compression — the reverse of what a diesel needs — which is where you hear the clattering.
Seen together, they make clear the shape the issue has. It's movement that does the harm, not contact. All a tank with petrol in it amounts to is a fuel fault. Whatever a worn pump sheds travels on, carried by your fuel, into your injectors downstream, which is why a pump that has been working on that petrol is where a mechanical fault starts.
Petrol in a diesel around Houston: how bad is it? Four cases
The best case there is: filled up, never started. Only the tank has petrol in it, so the job is clearing your tank and purging your system where your car sits. This situation can only truly occur at a forecourt: anywhere else, the car got there by being driven.
Ignition on, or started for a second. The fuel system has been bled, so petrol has left your tank and got to the filter and the fuel lines. Drain, flush, deal with your filter: still usually easy.
Those few miles on the road meant your pump labouring on fuel diluted by petrol throughout. Distance is only half of that; how hard it was driven counts just as much. Either way the work runs to that tank, the fuel lines, the fuel filter and fresh fuel through the whole circuit. The school run to the local primary school is one matter. Driving as far as Glasgow, under 15 miles away, makes a very different task — as does any mileage on the M8, under 3 miles from Houston, with your engine running hard all the way.
Driven on till it complained — rattling, smoke, a ragged idle, a soft throttle. The fuel isn't acting like diesel any more, and the motor is saying so. Leave it where it has stopped: a lay-by, a side street, the verge on North Street. What comes first is still the drain and flush-through, and that deals with it, with lasting damage very uncommon if a car is stopped quickly.
Houston people and the petrol in a diesel myths they hear
Myth: topping up to full with diesel makes it fine. It does not. Nothing is removed when you top up — the tank just holds more of the same mixture. The idea behind that advice — that diesel fuel systems accept petrol by percentage — is wrong.
"Current diesels can handle a little petrol" — a myth, and closer to the opposite. A current diesel sends its fuel through smaller components at higher pressure, which makes the protection count more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no harm done." Any petrol motor fed diesel normally will not run, so the driver stops and the damage stops with them. Feed petrol to a diesel and it generally fires up, idles and pulls away like nothing has happened — all the while its pump is wearing. Being able to run isn't proof of being fine.
An outdated fix for a separate issue is behind this one. Myth: "Add some two-stroke oil and drive the vehicle home." None of what petrol diluted is put back by it — and afterwards, the tank still contains that petrol.
"Drain it yourself and you're sorted" — a myth, since after it has been running some petrol lies in your filter and lines, waiting to go right back through your pump on the next start. Besides, petrol cleared into a can by the road is genuinely risky.
How petrol ends up: petrol in a diesel
It's rarely carelessness, and no one does it on purpose. One way only, because of the nozzles: the smaller petrol one slips inside a diesel filler with almost no resistance, whereas the diesel one mostly will not fit a petrol car. That is how the forecourt makes it simple.
When habit and the car stop matching, it takes place. Any vehicle that's new to you — hired, on loan as a courtesy car, or just bought. Two cars on one drive, one petrol, one diesel. A familiar forecourt with the pumps in a different order. Filling up in a hurry en route to Bishopton, with a train to catch. A new-to-you diesel Skoda Octavia, its first fuelling, and a driver accustomed to petrol: exactly when it takes place. With rain, a call coming in, or a car full of children to deal with, the hand just does what it has always done.
Houston motorists: how to prevent petrol in a diesel next time
- Green for unleaded and black for diesel is usual in the UK — yet not on each forecourt. Go by the label on the petrol pump, not the colour.
- Check your filler flap. Plenty of motors state the fuel type inside the flap or on the cap. Look at it on the first fill in a vehicle you do not know.
- Label 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 meaning to remember.
- "Diesel", aloud, before you pick up the nozzle — every time a new or hired car needs its first tank. It seems silly. It does the trick.
- Tuck your phone away. This is an easy mistake to make whilst you are thinking about something else.
- Add-on devices are available for cars without one, and some diesels come with a filler that won't take a petrol nozzle. Useful — but a safety net only, never a reason to stop checking the label.
- Noticing it mid-fill? Stop there and then. A thinner mix follows from less petrol inside your tank, yet the next step remains the same: don't crank it.
Already put petrol in a diesel in Houston?
Then, there is only a short order of things. Starting it is out, and so is turning on the ignition. The staff on the forecourt — whether at Morrisons itself or wherever you filled up — will usually help roll it away from the petrol pump if you ask. Phone 0333 366 0103 next, with three answers — the fuel, the approximate volume, and whether it's run.
Say so if it was AdBlue rather than petrol: it is a different fault, with its own page for Houston, because AdBlue brings corrosion and deposits instead of lost protection.
Why one petrol in a diesel task around Houston costs more than another
There's no fair single quote for this, since the four scenarios above are four separate tasks. The situation itself does most of the work of moving the cost. Two things come after that: the petrol that got in as a proportion of what that tank holds, then the spot your car is in and whether a van can get to it safely.
That is why we ask three questions before pricing instead of after: what went in, how much, and whether it has run. With the answers, you get a straight figure instead of a range.
About Houston, briefly
Houston is a village in Renfrewshire, situated on the banks of a river at an elevation of 38 metres, with Glasgow approximately 12 miles to the east. Houston is characterised by its predominantly detached housing stock, reflecting its relatively affluent demographic. Houston sits within a network of nearby settlements, including Crosslee, Craigends, and Ranfurly, and is located about 351 miles northwest of London.
Houston and Renfrewshire: where our fuel drain cover reaches
Houston rests in the PA postcode area, and the teams that answer petrol in diesel call-outs there work the spots around it as well — Crosslee, Craigends and Ranfurly among them. Our technicians drain wherever the car is — your own driveway, a lay-by, a supermarket car park, a forecourt — so it never needs to come to us.
At the pump around Houston, still?
No position is better: that is where you are. Switched off it stays; then ring.