When I start my dryer, it sometimes makes a noise like the motor is struggling to turn. It will stop midway through its drying cycle. It will only restart, or make that noise after I have unplugged it and let it sit for a while. Could this be a power supply/relay issue, or a motor issue? This is a old dryer.. But in good shape. I want to try to repair it. Any advice would be greatly appreciated!!

Thank you!