I just acquired a 91 560sel. The sunroof will slide back and forth but will not flip up. When I try to flip the roof up, only one side will slightly go up and the other is still down. it looks like something is making it stuck in that position? I can hear the motor running and the motor seems fine. What can be wrong?

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2001 E55

2001 E320 Sedan

2001 Subaru Legacy

2006 SLK280

2016 Subaru Outback 3.6