knocking

91,000 MILES • 6 CYL • 2WD • AUTOMATIC
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MAILMAN417
  • MEMBER
  • 1 POST
My pontiac grand prix 2002 makes a knock sound on acceleration and deceleration sometimes. Any thoughts on where to start?
Feb 24, 2011 at 10:36 AM
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JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,248 POSTS
The first thought is cam bearings. Check to see if you can tell if it is a low end sound from the engine or if it sounds like it is coming from the top. If the top, the cam is my first guess. If a low end knock, it could be rods or main bearings.
Mar 20, 2011 at 8:57 PM
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