Should You Worry? Petrol in a Diesel Car in Callow Hill
If it has not been started, worry far less than you probably are. Petrol sitting in a diesel tank does nothing to your motor till something pulls it through your fuel system — your ignition priming your pump, the starter, or driving itself. So the fair answer to the first question everyone in Callow Hill asks, "have I ruined it?", is usually no. Petrol in Diesel is who to phone, with the motor left off, and so it stays that way. The rest of this page sets out what petrol actually does to a diesel, how to judge how far it has got, and how to make sure it doesn't happen to you again.
Inside the motor: what petrol in a diesel really does
Diesel has two tasks on its way through an engine. It combusts, and before it ignites it lubricates. Extremely fine gaps go into the injectors and the high-pressure pump, and just your diesel running through keeps their surfaces from grinding together.
Badly at the first, not at all at the second: that is petrol. Being less viscous than diesel, petrol strips away the protection a fuel system needs, so a pump running on that mixture to wear itself. It is also made to resist igniting under compression — the reverse of what a diesel needs — which is why you hear the clattering.
Combined, those make the shape of the issue plain. It's circulation that causes the harm, not contact. Where that petrol is only inside that tank, it's an issue of fuel, nothing more. The start of a mechanical one is a pump that has been labouring on that petrol — and whatever a worn pump sheds travels on with your fuel to the fuel injectors beyond it.
How serious is petrol in a diesel? Four situations our engineers see in Callow Hill
Fuelled up, never started. The best case there is. Just the tank has petrol in it, and so the job is emptying the tank and rinsing the fuel system where your car sits. This situation can only really occur on a forecourt: anywhere else, the car got there by being driven.
Ignition on, or started for a second. Petrol has come out of the tank and reached your filter and your lines, because your system has been bled. Drain, flush, deal with the filter: still usually straightforward.
Your pump has spent a few miles on diluted fuel — that is what driving it does. The work is the tank, your lines, the filter and clean fuel through the entire system, and how hard your car was driven matters as much as how far. A school run to The Vaynor First School is one thing. A run as far as Worcester, under 15 miles away, is a very different task. So is any miles on the M42, under 10 miles from Callow Hill, where the motor has been running hard the whole time.
Driven on till it protested — rattling, smoke, a lumpy idle, a soft throttle. The fuel is not acting like diesel any more, and the engine is telling you. Stop wherever you are — the verge on Foxholes Lane, a lay-by, a side street — and leave it there. A vehicle stopped soon very seldom has lasting damage, as the drain and the flush-through, which still come first, sort it out.
Callow Hill drivers and that petrol in a diesel myths they hear
Myth: "Fill it the rest of the way with diesel and it'll be fine." It will not. Topping up takes out nothing; it gives you a bigger tank of the same mix. That advice presumes a diesel fuel system tolerates petrol by percentage. It doesn't.
Myth: "A newer diesel can cope with a bit of petrol." If anything, the reverse. At higher pressure, through more precise parts: that's how a current diesel moves its fuel, so the lubrication counts for more, not less.
This is the one that fools motorists. Myth: "If it starts and drives, there's no harm done." The driver of a petrol engine fed diesel usually stops, since it will not run, and the damage stops with them. Feed petrol to a diesel and it normally starts, ticks over and pulls away like nothing happened — all the while its pump is wearing. Fine and running are not the same at all.
Myth: a two-stroke additive lets you to drive home. It is an old fix, meant for another fault. That petrol is still in your tank after that, and whatever it has weakened isn't put back.
"Drain it yourself and you're sorted" — a myth, because after it has been running some petrol lies in the filter and lines, waiting to go right back through the pump at your next start. Clearing petrol into a can at the kerbside is also genuinely dangerous.
How it happens: petrol in a diesel
On purpose? Never. Through carelessness? Rarely, if ever. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly won't go into a petrol motor at all. So the slip runs one way.
It takes place when routine and the vehicle stop matching. Hire cars, courtesy cars, and cars that are new to you. A household with one petrol and one diesel on the driveway. Your normal forecourt, its pumps suddenly in a different order. A train to catch, and a rushed fill en route to Redditch. Exactly the moment it occurs: after years of driving petrol, someone fills a diesel Volkswagen Golf for the first time. Your hand does what it has always done once you add rain, a phone call or a back seat full of children.
Next time you fill up in Callow Hill: preventing petrol in a diesel
- Check the pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on every forecourt. The label is what matters.
- In a motor you don't know, look inside the flap over your filler or at the cap before your first fill: plenty of motors print the fuel type there.
- Mark the key. In a house with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- It seems silly and it does the trick: on your first fill in a new or hired car, say "diesel" aloud 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 come with a filler designed to block a petrol nozzle, and devices you can add are available for cars without one. Such an inhibitor helps up to a point — as a backstop, not a reason to stop reading the petrol pump.
- The moment you notice, stop: less petrol in that tank means a thinner mixture. What to do next does not change, though — still don't start the vehicle.
Petrol already in a diesel in Callow Hill? Start here
Short and simple, then, is the order of things. Leave it unstarted, with the ignition off as well. Still on the forecourt, at Tesco or anywhere else? Ask the attendants to help you push the vehicle clear of the petrol pump. Next, 0333 366 0103. We will ask what went in, about how much, and if it's been run.
Corrosion and deposits form the problem with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and read its own Callow Hill page.
One petrol in a diesel task around Callow Hill costs more than another. Why?
The four situations above are four separate jobs, so no single quote for this would be honest. Chiefly, the cost shifts with which situation you're in. Where your car is counts too, and whether our van can safely get to it, after the share of petrol to what your tank takes.
That is why we ask three questions before quoting instead of after: what was put in, how much, and whether it has run. The answers turn a range into a straight figure.
About Callow Hill, briefly
Callow Hill is a suburban area in Worcestershire, situated inland at an elevation of around 138 metres. Callow Hill lies approximately 12.5 miles northwest of Worcester and about 95 miles west of London, near the settlements of Walkwood, Hunt End, and Headless Cross. Callow Hill is characterised by its predominantly detached housing stock, reflecting its residential nature.
Across Worcestershire and in Callow Hill: fuel drain cover
Petrol in diesel call-outs around Callow Hill — part of the B postcode area — go to vans that also cover the locations about it, Walkwood, Hunt End and Headless Cross included. The car does not 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 Callow Hill and still at the pump?
Then you are in the best place there is. Keep the car turned off, then ring.