engine noise

Hi all,

Im having a issue with my 2010 octavia vrs ive had it to dealership with no fault found as is intermitent problem.

only way the noise can be described is- when a car has been parked up for a while and the brakes catch on but is coming from the engine it is a radial noise does it whilst idleing and also gets faster when you axcellerate. I have a video recording of the sound but dont know how to attach.

Its like a scraping metal sound like the engine is pulsing also could be described as a saw going backwards and fowards. ? Car running fine apart from this noise..

The car is diesel. Im stumped..

can only be heard from inside car not outside

Id upload a video but i dont know how.