My left fan sounds like a piece of paper is stuck in there when it kicks in (slap-slap-slap-slap). I looked carefully but can't find anything down there. Any ideas what could cause a sound like that?

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1994 C 280 117.5k, White (Good as new)
1997 Toyota Camry 149k Miles (Not so pretty anymore)

1990 190e 2.6 95k (Sold-Should not have)
1981 240d Stick ??? Miles...sold