Petrol in a Diesel Car in Tarry Hill: How Worried Should You Be?
Less than you likely are, provided it has not been started. "Have I ruined it?" is the first question everyone around Tarry Hill asks, and the honest answer is normally no, because petrol resting in a diesel tank harms nothing till it is dragged through the fuel system — by ignition priming, by your starter, or by being driven. To keep the car that way, phone Petrol in Diesel then leave the motor alone. Further down, this page sets out what petrol actually does inside a diesel, how far it may have got, and how to stop it happening to you a second time.
What petrol in a diesel does to the motor
Passing through an engine, diesel does two jobs at once. Oiling comes before burning; it does both. Very fine gaps go into your injectors and your high-pressure pump, and only the diesel flowing through stops their surfaces grinding together.
Badly at the first, not at all at the second: that's petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, leaving a pump running on that mixture wearing itself. It is also made to resist igniting under compression — the opposite of what a diesel needs — which is why you get the rattling.
Put these together and the shape of the trouble is clear. The harm is done by movement, not by contact. A tank with petrol in it is a fuel fault. 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 your fuel to the injectors further on.
How bad is petrol in a diesel? Four scenarios our engineers see in Tarry Hill
Fuelled but not once started — the best it gets. At a forecourt, and truly only there, that petrol is still limited to your tank — since everywhere else the car was driven to get to it. The job is emptying and rinsing on the spot.
Started for a moment, or only the ignition on. Petrol has come out of the tank and got to the fuel filter and the lines, since your system has been primed. Drain, flush, see to your filter: still usually straightforward.
The pump has worked a few miles on thinned fuel — that's what driving the vehicle meant. The work is that tank, your lines, the filter and clean fuel through the entire circuit, and how hard the car was driven counts as much as how far. A school run to Swineshead St Mary's Church of England Primary School is one thing. Driving as far as Lincoln, under 50 miles away, makes a very different job — as does any miles on the A1(M), under 50 miles from Tarry Hill, with the engine working hard the whole time.
Rattling, a lumpy idle, smoke, a throttle gone soft: driven till it complained. That's your engine telling you its fuel no longer is behaving like diesel. Pull up on the spot — on the verge on Cole's Lane, at the kerb, down a side road — and do not move it again. Lasting damage is very unusual if a car is stopped early, and the fuel drain and flush that still go first take care of it.
Stories Tarry Hill motorists 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 when you top up — your tank simply carries more of the same blend. Percentage isn't how a diesel fuel system tolerates petrol, however much that guidance presumes.
"Current diesels can handle a little petrol" — a myth, and closer to the reverse. Lubrication matters more on modern diesels, not less, because their fuel runs through more precise parts at higher pressure.
"It starts, it drives, so there is no harm" — the myth that trips up more drivers than any other. Feed diesel to a petrol motor and it normally will not run, and so the driver stops — and the damage stops with them. Whilst the pump wears, a diesel fed petrol usually starts, ticks over and drives away as though nothing has happened. Running isn't the same as fine.
"A drop of two-stroke oil and drive it home" — a myth, taken from a fix from years ago, for a different fault. That petrol is still in the tank after that, and what it has thinned is not put back.
"Drain it yourself and you are sorted" — a myth, because after it has been running some petrol sits in the fuel filter and lines, waiting to go straight back through your pump at your next start. Also, a can of petrol drained at the roadside is truly hazardous.
How petrol ends up: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, 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, while a diesel nozzle generally will not go into a petrol motor at all. So the mistake runs one way.
When habit and the vehicle stop matching, it takes place. Courtesy car, hire car, or a motor that is new. Two motors on one driveway, one petrol, one diesel. A forecourt you know, only with its pumps laid out differently. A hurried fill en route to Swineshead with a train to catch. Precisely the moment it happens: after years of driving petrol, someone fills a diesel Volkswagen Passat for the first time. The hand does what it has always done when you add rain, a phone call or a back seat full of children.
How to prevent petrol in a diesel at your next fill-up in Tarry Hill
- The label is what counts, and so read the pump instead of the colour: in the UK unleaded handles are normally green and diesel black, yet not on each forecourt.
- Inspect the filler flap. Plenty of cars state the fuel type inside the flap or on the cap. Look at it on the first fill in any car you do not know.
- Mark the key. In a household with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of intending to remember.
- Before the nozzle comes off the pump the first time you fuel a hired or new motor, say "diesel" out loud. Daft, perhaps, yet it works.
- Tuck the phone away. This is an easy mistake to make while you are thinking about something else.
- Some diesels have a filler built to reject 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 reading the petrol pump.
- Stop the moment you realise. Less petrol inside the tank means a thinner mixture. It doesn't change what to do next, which is still not to fire it up.
Put petrol in a diesel in Tarry Hill already?
Then, there is just a short order of things. Starting it is out, and so is switching on the ignition. If you are still at the forecourt — Esso or anywhere else — ask the attendants to help you push the vehicle away from the petrol pump. Then phone 0333 366 0103 and tell us what went in, about how much, and whether it has run.
AdBlue, not petrol? Then say so. Corrosion and deposits, not lost lubrication, make it a different problem — Tarry Hill has a page all for it.
Why one petrol in a diesel task in Tarry Hill costs more than another
The four scenarios above are four different jobs, so no single price for this would be fair. What shifts the cost is mostly which of them you are in. Next it is the ratio — how much petrol was put in against how much that tank takes — and after that where the vehicle is and whether a van can get to it safely.
Before any quote, not after, come three questions: your fuel that was put in, the volume, and whether it's run. That's why. Those replies change a range into a straight figure.
About Tarry Hill itself
Tarry Hill is a suburban area in Lincolnshire, situated inland at a low elevation of around 3 metres. Tarry Hill lies approximately 25 miles from Lincoln and 99.7 miles from London, placing it in a relatively rural part of the East Midlands. Tarry Hill is characterised by its predominantly detached housing stock and is near to other small settlements such as Swineshead and North End.
Fuel drain cover around Tarry Hill and across Lincolnshire
Petrol in diesel call-outs around Tarry Hill — part of the PE postcode area — go to teams that likewise cover the places around it, Swineshead, North End and Baythorpe included. A forecourt, a supermarket car park, a lay-by or your own drive are all spots our technicians work, and the car doesn't need to come to us.
In Tarry Hill and still at the pump?
In that case, you couldn't be in a better position. Switched off it remains; then phone.