Alternator

2005 CHEVROLET TRAILBLAZER
75,000 MILES • 4.2L • 6 CYL • 2WD • AUTOMATIC
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THOMASSTURGILL
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I have this intermittent rattle noise coming from the front of the motor. Just replaced the alternator clutch fan and water pump. If i put a piece of metal to the alternator i can hear it and feel it. If i do the same thing to the block and all the other components no noise. Also, the noise goes away when i remove the serpentine belt.
Jan 20, 2018 at 3:38 PM
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ASEMASTER6371
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Good morning.

Have you replaced the alternator as a unit or just the front section?

if you spin it by hand, can you hear the noise?

Roy
Jan 21, 2018 at 4:51 AM
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THOMASSTURGILL
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The shop put a GM re-manufactured full replacement. The has a slight tight spot when belt is off and rotating by hand. When i place a metal rod along the block and all the other pulleys i have no noise but it is really loud in the alternator and really low sounding around it.
Jan 21, 2018 at 5:23 AM
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ASEMASTER6371
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Okay, good chance the new alternator is no good. have you spun the power steering pump, AC clutch, tension-er pulley and idler pulley?

Roy
Jan 21, 2018 at 5:30 AM
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THOMASSTURGILL
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All are good i have had the harmonic balancer replaced with the updated version. The noise is only there during idle and not under-load.
Jan 21, 2018 at 6:56 AM
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ASEMASTER6371
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Okay, then it sounds like you have a bad new alternator.

Roy
Jan 21, 2018 at 6:59 AM
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THOMASSTURGILL
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Okay thank you so much for the information. I have an appointment Tuesday to get it changed.
Jan 21, 2018 at 7:26 AM
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ASEMASTER6371
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You are welcome.

Roy
Jan 21, 2018 at 7:27 AM
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THOMASSTURGILL
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I just removed my belt and the alternator pulley has a squeak to it.
Jan 21, 2018 at 8:09 AM
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ASEMASTER6371
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that is not good. should be making no noise at all.
Jan 21, 2018 at 8:10 AM
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THOMASSTURGILL
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Okay.
Jan 21, 2018 at 8:14 AM
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THOMASSTURGILL
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Well got the alternator switched out and the problem is fixed.
Jan 23, 2018 at 10:31 AM
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ASEMASTER6371
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nice job. we even get fooled by bad new parts

Roy
Jan 23, 2018 at 11:58 AM
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THOMASSTURGILL
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Yes we do and thank you for the info.
Jan 23, 2018 at 12:43 PM