not sure if this related to your problem but here is one TSB - 127
SERVICE ACTION: INSPECTION FOR NOISE FROM ENGINE UNDER SPECIFIC CONDITIONS (SA 141)
This bulletin provides information relating to certain 2013MY Rio (UB vehicles which may
exhibit abnormal engine noises, including "rattling" and "chattering", under specific conditions.
Only a very small number of vehicles within the identified Production Date range will actually be affected; make sure to follow the detailed instructions and recently updated inspection procedure in this bulletin to prevent unnecessary engine replacements. This procedure applies to vehicles produced from August 09, 2012 to October 09, 2012.
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