pontiac grand prix 3.8L ticking knocking noise when cold

2005 PONTIAC GRAND PRIX
144,000 MILES • 3.8L • V6 • FWD • AUTOMATIC
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GUMBY21NE
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I have a 2005 pontiac grand prix with 144,000 miles on it. After the first freeze this year, it started making a loud tapping/ticking/slapping noise from the bottom of the engine compartment just like in this video http://www.youtube.com/watch?v=Yfw08eFUWZk

The video is of someone else's 2006 Grand Prix but it is the exact same noise and situation. It only happens when the vehicle is cold and the sound gradually fades as the vehicle warms up until it is completely gone.

The is no check engine light on or pending codes. The vehicle drives fine.

I got the oil changed shortly after the noise started but no change. I had the transmission rebuilt/replaced 3 months ago.
Nov 14, 2014 at 4:08 PM
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HMAC300
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he a local guy look at it but from what you describe it may be piston slap as it goes away when warm. it doesn't do any harm just sounds bad. btw your link didn't work.
Nov 14, 2014 at 4:14 PM
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GUMBY21NE
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I am sorry about the link. For some reason extra spaces got added when I pasted it. The guy in the video thinks it might be something else. I am starting to think it might be the flex plate rubbing against the torque converter cover which may have been improperly installed. Just don't know why it would start making noise as soon as it got cold.

The video does really help explain the sound I am hearing

http://www.youtube.com/watch?v=Yfw08eFUWZk
Nov 14, 2014 at 4:19 PM
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HMAC300
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Check your torque converter bolts they may have loosened up. if they are remove them one at a time put new Loctite on them and torque them to about 40 ft lbs.
Nov 14, 2014 at 4:42 PM