I thought that this noise was due to dirt/rust at pulleys/belts. The noise is heard both at idle and when the engine is running and it is at the same frequency.

I sterted by applying wd40 at the belts but nothing changed and so by listening more carefully, I think that the noise comes from the area around my catalyst.

I replaced my starter lately but I am sure I fastened all bolts very securely and I think (but I'm not 100% sure) that I had that noise before.

What could cause that noise if it is indeed around that area? could it be the new starter? or the catalyst ?

 

hard to say without a proper description of the noise.
Video will also help

 

I was planning to upload one on Youtube but now I don't have the noise. I switched off the car after a trip and now it's gone. I'll try to make a video when the noise returns. I guess before I switch off after a trip.

 

Ok, it took me a while as I was very busy but here is the video of the noise. Try to notice that the noise becomes more noticable when I place the camera under the engine and especially in the left hand side of the car. Also the noise doesn't go away when the engine is warm. It is always the same even after a trip.

"http://www.youtube.com/watch?v=iMXqx48UUAI"

 

Bad engine mount.

 

thanks.
Is that easy to replace or do I need special equipment to hold the engine in order to replace?

 

Floor jack, 2x4 for under the oil pan. It's pretty simple to do if your mechanically inclined.

Best bet is to remove the wheel and look in there at it.