So what are your full hardware specifications including the model of your graphics card AND how long has it been in service?
Did you buy it new or used?
Honestly, it is most likely a bearing and will probably need replacement of the fan assembly or entire cooler depending on how it is configured, but it could also be that the cooler assembly is simply loose on the card and needs to be snugged back down. It could also be a problem with the motor assembly itself such as a loose or broken brush riding up against the rotor or some other loose component inside the motor. Fans don't thump unless something is physically wrong.
If it is not hitting something and can turn freely, but simply ISN'T turning freely, then I'd say you probably need to replace the fans or the whole cooler, depending on the card.
So what are your full hardware specifications including the model of your graphics card AND how long has it been in service?
Did you buy it new or used?
Honestly, it is most likely a bearing and will probably need replacement of the fan assembly or entire cooler depending on how it is configured, but it could also be that the cooler assembly is simply loose on the card and needs to be snugged back down. It could also be a problem with the motor assembly itself such as a loose or broken brush riding up against the rotor or some other loose component inside the motor. Fans don't thump unless something is physically wrong.