Petrol in a Diesel Car in Penrhos Garnedd

How far you went is what our technicians query, not how long your car has been stood — and here is why. Diesel has two jobs on its way through an engine: it burns, and before burning it lubricates its high-pressure pump and the injectors. Petrol handles the first only. So a quick top-up on the trip in, it dawning on you at about eleven, and a diesel Renault Megane parked outside Bangor (Gwynedd) since quarter past eight shows those few miles were done with your pump labouring on a fluid robbed of a great deal of its protection. Phone us then keep the car just where it is.

Car parks like the one outside Tesco Extra are a place our technicians visit often, and your fuel is rarely the complicated part. That bay is: cars either side, a trolley shelter behind, at times a height bar on the way in that settles if a technician can reach you at all. So tell us how penned in you are when you phone, and which way the car is facing. Where we cannot work beside your diesel Volkswagen Passat we will move the vehicle without running it — and that's not pedantry about a handful of seconds of running. Every start primes that fuel system and sucks more of that blend out of that tank and toward your pump, so a vehicle shunted twice into a roomier bay has quietly grown into a harder job than one left exactly where it stopped.

Nothing alerts you, because from the driver's seat there is nothing to be warned about. Your diesel Mercedes E-Class will have seemed perfectly usual on the way back from the local primary school, and they all do — which is the catch with petrol in a diesel instead of the reverse. Diesel in a petrol vehicle mostly refuses to run, stopping the driver and stopping the damage with them. Petrol in a diesel fires up, ticks over, moves off as though nothing had happened, and all the while the pump works without the lubrication its fuel is meant to supply. Tell us approximately how far, and how hard. The harder matters more.

Draining the Peugeot 208, changing the fuel filter where there is a workable one, flushing the lines, putting clean fuel through the whole circuit: that is the job, and it's shaped by the worst of that waiting in the fuel lines instead of in that tank by this point. Three things help when you ring from near St Peter's Church — which side the filler is on, whether our van can park next to without blocking the road, and if your engine has run since you filled up. On-street is the most common place we work, so the location itself is hardly ever the trouble. A narrow parking space trumps a motor driven somewhere more convenient.

Repaired and starting are not the same thing, and the difference is your circuit: our engineers flush it, and take your filter off where there's a serviceable one. Compare that with the confident suggestion you'll get — drain the vehicle, refill with new diesel. Only half right. Do exactly that to a diesel Ford Fiesta near TK Maxx and it will start, which is exactly why the advice sounds sensible. Then the motor sucks the petrol left behind in the filter, and in the feed lines, straight back through the pump, since emptying a tank does nothing whatever about fuel that has already left it. Call us instead.

Penrhos Garnedd: stranded wherever you stopped

Not everybody has a sensible place to pull in. Hazards on at a lay-by somewhere, or stopped on the verge beside Ffordd Penrhos as you noticed after setting off — our technicians take that call often enough that it is the usual kind.

Whether you remain with the motor or stand away from it depends on whether staying there feels safe. It will usually oblige. A diesel running on petrol limps along perfectly willingly, and that is the problem: start it up to reach somewhere safer and the blend goes further into your fuel system with every mile covered. A technician heading to an awkward place is no bother for us, and it's a lot better for the car than carrying on.

Where is Penrhos Garnedd?

Penrhos Garnedd is a suburban area situated on the coast of northwest Wales, near the city of Bangor. Penrhos Garnedd sits at an elevation of 91 metres, overlooking the surrounding landscape. Penrhos Garnedd is characterised by its predominantly detached housing stock, with nearby places including Coed Mawr, Bryn-Llwyd, and Capel-y-graig.

Penrhos Garnedd pricing for a petrol-in-diesel fuel drain

Our technicians cannot put one number on this page frankly, because the job isn't one job. What shifts it:

• Has it been started or driven? Nothing else counts for as much.
• How much of the wrong fuel went in, set against how much that tank holds.
• Which was put in: unleaded or AdBlue.
• Whether a van can safely get to your vehicle and work on it, which hinges on where your vehicle is.

Tell us what the car is, how much went in, and if your engine has run. A firm answer comes back, not a range. Not urgent, with the vehicle at home and going nowhere? Then does the job.

A few litres of petrol in a diesel — too much?

Ratio decides it instead of litres — and more than either, whether your engine has run. An almost empty tank with five litres in it, against a full one with the same five: distinct scenarios, of course. Either way, the work needed comes down to one thing, which is if the fuel system has had that mix pulled through it.

My warranty — does a fuel drain void it?

No. Carried out properly, draining and flushing is no alteration at all, and the warranty from your manufacturer is untouched by it. A disagreement over a warranty is likelier to come from running a diesel on petrol — so leave it turned off.