Hello All

 

I managed to fill my diesel Octavia VRS with petrol this week. Unfortunately I didn't notice and drove it off the garage forecourt. It ground to a halt after a mile or so. I had it recovered to a friend's garage who drained the petrol, and replaced it with diesel. I have the car back now and it seems to be running fine, apart from a buzzing  sound from the top left of the engine bay. Not sure what the part does that is buzzing but it's to the right of the washer filler and sits under a metal plate secured by two bolts (see picture). Is anyone able to identify the part and advise why it's now making this buzzing sound? The sound can be heard from inside the car.

 

Thanks

Russ

I hope they did more than just drain the petrol and replace with diesel...

 

You need the entire fuel system cleaning and filters replacing. There is a good chance you've damaged the HPFP (high pressure fuel pump) which can fill your injectors full of swarf as it breaks down. Not sure exactly where the HPFP is but I doubt it's far away from the fuel filter which is next to the washer fluid IIRC.

All fixed now. It turned out to be the aux fuel pump buzzing. The reason was that when the garage took the tank pump out to drain and clean it, they managed to switch the feed and return hoses up. For some reason this causes the pump to get noisey after about 20 mins driving. It appears to be quite a common mistake. 

 

Car is back to normal with no sign of any damage to the HPFP or injectors.

 

Cheers

Russ