Strange Noise Since 3g Alternator Upgrade

fox-gt

Member
Feb 28, 2004
203
0
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TN
I upgraded to a 3G alternator in my 93 GT. Every since the upgrade I have a strange noise coming from the engine bay. Car runs perfect, good oil pressure, etc. I noticed the back of the alternator was resting on the bracket. Is it supposed to be touching? If not, could it be vibrating against it. The noise sounds like you are shaking a cup full of rocks. It didn't happen until the upgrade.
 
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a91what

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Apr 6, 2011
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Open hood, start car, listen for noise.... you can use a stethoscope or even just a long screwdriver to listen for the bad bearing.
 

mikestang63

SN Certified Technician
Aug 27, 2012
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did you notch the bracket for clearance for the 3g alternators? No it should not be resting on the back of the bracket.
 

Shakerhood

15 Year Member
Oct 28, 2004
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Hard to tell from those pics but it does look like the case may be making contact with that bracket, you may just need to do a little more.
 

fox-gt

Member
Feb 28, 2004
203
0
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TN
It is clearing now.
20160704213701-7e40fd4d-me.jpg


I think I have narrowed it down to the smog pump (which I need to pass emissions here in TN).

I'm going to switch to the 2G pulley too, the belt is very tight.

Thanks everyone.
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Smog pump bearing is a KOYO 6203-2RS bearing...standard 40mm OD x 17mm shaft x 12mm thick sealed bearing. About $5

If you disassemble the smog pump.(a bit tricky, but not hard once you understand how it comes apart) you'll find that bearing can be replaced.

Beats buying an entire pump.
 
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90sickfox

I didn't really have an issue with the stink...
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Glad you found the problem [emoji106]
 
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