Strange problem with Megane:(

[flangemanager]

Hello
I'm experiencing a really odd problem with my Megane f1. This has occured about twenty times since I bought the car 4 months ago. Since purchasing the vehicle I have had it serviced, had the belts, pump and tensioner changed, replaced the spark plugs and injectors and also had it MOT'd which included an oil filter and fuel filter change. For reference, the discs and pads are also ok.

Basically, sometimes when setting off from a cold start the car makes a loud metal against metal clunk, followed by the sound of metal against metal grinding /grating. The car struggles to maintain power and the revs fluctuate. I end up setting off "bunny hopping" slightly. This last for about ten seconds and then the car drives without fault. I am totally stumped as to what's causing this and although it doesn't happen often, it really worries me when it does. I have also noticed that the car has started making a vibrating sound, almost as though something is working its way loose.

Does anyone know what might be causing this?

Thanks. Michael.

[freelanderuk]

Could the hand brake be sticking on

[flangemanager]

I had the handbrake checked over. It's not that:(

[livewire]

yes most strange.
as would expect any noise like that to just get worse, then obvious what the cause is.
from what you describe sounds like the bottom drive pulley.
not sure about the megane but on a Citroen they have a kind of rubber bearing in the pulley that often fails.
had one go and was kind of like what you describe, but did just get worse.