Laptop cpu overheats and fan doesn't spin at full speed

[Reinsetten]

I have an acer aspire e1-571g for 2 years already and last week i encoutered a problem: the laptop fan started to make a disturbing noise for like 2 days and i slapped it to make it stop (im an idiot yea..) but i didnt really slap that hard and the the sound lessened and everything was ok( all that time i was playing a game) and after 1 or 2 hours the cpu started overheating reaching 85C+ and immediately shutting down itself while reaching 90C.
I opened it and took of the motherboard to acces the fan, indeed some dirt was there, i cleaned it and put everything back, all ok, but the problem persisted. The thing is that the cpu overheats because the fan doesnt spin at full speed anymore and i dont know why, it just has the normal speed regardless of what i play or do on it. The fan spins at full speed when i turn the whole laptop vertically or just turn it upside down(its pretty weird) and if i put it back on the table it works for like 2 minutes more and again it spins normally. Any opinions ? ive heard that the thermal paste should be replaced but i dont know if it would help because if the fan starts at full speed everything will be ok, also the fan might be damaged because it starts when i move my laptop, anyone please any ideas... ?
Thank you all

 

[Hamperking68]

With a problem like this it is a good idea to replace the thermal paste before attempting to track down a spare fan but it sounds like you may need to replace the fan assembly.

 

[Reinsetten]

With a problem like this it is a good idea to replace the thermal paste before attempting to track down a spare fan but it sounds like you may need to replace the fan assembly.

i cleaned the fan yesterday and it worked at full speed for like 5 hours but it was making a weird noise and after around 5 hours it started to go back at the slow rotation. This morning when i did open the laptop the fan wasnt spinning at all only after 10 minutes after letting the laptop open, it sounds pretty silent but it the fan sounds like it lacks of power or battery or something like this, like it is struggling somehow to spin. I cleaned it 3 times im pretty sure it is not at all. Any ideas ?

 

[velo3100]

First replace the thermal paste. If that doesn't work check if the fan is damaged in any way. The other thing could be the hdd as they can produce heat when they are old. Check that is not damaged.

 

[Reinsetten]

First replace the thermal paste. If that doesn't work check if the fan is damaged in any way. The other thing could be the hdd as they can produce heat when they are old. Check that is not damaged.

the hdd temp is under 30 degrees, the cpu and gpu temp is over 70. In any case what if i buy just another fan and mount it by myself because a service to diagnose my laptop and put thermal paste/ cpu is 40$ and i dont have these money. I think the termal paste is ok btw

 

[velo3100]

If this temps are while gaming, you have nothing to worry about. But if this is in normal use or idle then you have a problem. Try replacing the fan like you said and see if this makes a difference.