Car makes noise shortly after starting up

So I'm reaching out for help here. I have a 2000 Focus that has recently been giving me a new problem about twice a month. The current problem is this terrible, somewhat grindy noise I hear within 30 seconds-1min after starting the car. The noise happens if it's in part or reverse or drive. It seems to me that it's coming from the front passenger side of the car. I cannot tell if it is a metallic or plastic noise. I took it to my mechanic about 9 days ago and he checked whatever he checked. All he said he found was a worn out strut mount, so he replaced that. No noise again until last night.

Does anybody have any idea what this is? Could it be related to my starter, or, like the strut mount, could it be another part of my suspension?

I seem to only hear it that once after starting, but it's a pretty terrible sound and I really want to get it fixed. Any ideas or suggestions would be greatly appreciated. Thank you!