Acer Nitro 5 AN-515-52 fans making grinding noises

As the title says one(or two fans) are making grinding noises. Tried thumping under the table in hope that this will fix it(once I've got in indentical situation,but fans then were quieter than now and that fixed it) but it didn't work. I have opened NitroSense to see the speed of the both fans and it seemed thta both are ok in terms of speed(cpu was running around 3500rpm and the gpu was running around 2500 rpm idle, which is normal as it was always like that, temps were ok). Decided to spin both fans using stick without dissasembly to see which fan is having difficulties in spinning(because I think that fan blades are hitting it's casing), I'm not sure but I didn't felt any difficulties spinning them both. Turned the laptop again and still same, but this time I think it got a bit louder(not that much) and when I turned NitroSense CPU reading were very low(300 to 200 rpm and even falling to 0 rpm) and I've  immediately turned it off to prevent damages. My question is can I fix fans without replacing one, I don't have time to order one and wait 2 months for it? Unfortunately warranty expired 8 days ago.