Siemens dryer has a extra swishing sound like something got behind the drum

It sounds like the drain is blocked with lint or mold gel.

It could be a squeal from the dryer belt. It could be from a belt that has gotten loose, like you hear on a car sometimes when it first starts up, but usually they don't get loose. They just break. Maybe something has gotten jammed between the dryer drum and the interior of the dryer making it hard for the belt to turn the drum and so it is squealing. Does the drum turn by hand without too much force and without squealing?

Probably drum rollers or a loose blower wheel. Either one is not major and a worthwhile fix

Sounds morelike motor brushes worn sold as Half motor in some models of this make....

drum rollers/glides:

http://www.partselect.com/dryer+dryer-tears-clothes+repair.htm

if it's a humming sound the motor is bad or something is jammed keeping the motor from spinning.open the dryer door and move the drum by hand if the drum can't be moved the belt could be jammed on something or there's something stuck in the blower wheel.the blower wheel is behind the duct that the lint filter slides into.if you can move the drum then you most likely have a bad motor,try spinning the drum and push the door switch in and have someone else push the push to start button and see if the dryer will start,if the motor has a flat spot it could start like this.let me know what you find

possible worn bearing.the more wear on the bearing the lower the drum will be.the drum sounds like its rubbing the bottom of the dryer.check for black dust behind the dryer

Sounds like an electronic problem on the timer circuit board.

does your dryer have a plastic glide on the drum or is it on the felt if some one gave you the wrong one that would make your problem worse there is two different types for that dryer

YOUR DRUM BEARING HAS GONE