ACER H6520BD (Model: D1P1338) rattling while starting - may fans dying?

Hi all,

while starting my beloved beamer makes loud rattling noises. After booting the average noise level is still above the level when I bought it first.
Therefore I think maybe one of the fans is dying? Or has anyone else experienced something like this and knows where the problem is?
I don't want to get rid of the beamer as it still works pretty well and I simply love it (just changed the bulb after 1000s of hours).

I thought of exchanging the fans and tried to find the appropriate parts. I opened it and saw 2 fans:

- a radial small one, where in the internet I found 2 possible exchange parts GB1245PKVX-8 with 1,2W and GB1245PKV1-8AY with 0,5W, both with dimensions 45 x 45 x 20. On the fan inside there seems to be no descriptions/information written on. How can I get the correct one?

- a straight one (like nomal pc housing fans), but there I can not find any information (on the fan itself or the internet) of a part number. anyone who knows which one is the correct one?

If the noise maybe comes from a bad connection between fan and housing, does anyone know a good way to decouple those?

Hope someone can help me