PS3 Fan Crazy Loud! Help!?

I have had my PS3 for about 4 years and it has gone through hell with me playing it all the time. It used to get really crazy loud but it died down a little bit and it wasnt a big issue anymore. 4 years later, (today) I have noticed the last week the fan is kicking into super high gear and im not sure why. I have vacuumed all of the vents out 2 times after the vacuuming, I used a blower on the vacuum to shoot out the vents if anything was left. Heres the thing though... When I first turn it on even from 3 days or so rest, the fan is normal, then like 5 minutes later it goes to its second setting of loudness/speed. After another 5 minutes it gets even louder, and then it gets even louder than that after 10 minutes more. There is no way it is overheating after only 20 minutes of it being on. I sent it back to sony to fix earlier like 5 months ago because it overheated and the cpu fried. it was fixed and now the fan is loud as balls... My dad said it is because the barring the fan spins on is wearing out and needs some oil. If the oil on the barring doesnt work can someone tell me what might be going on? thanks.