Strange Noise Since 3g Alternator Upgrade

fox-gt

Member

Feb 28, 2004

204

0

17

TN

Jul 3, 2016

#1

• Jul 3, 2016

• #1

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.

 

a91what

SendMeUrDataLog

10 Year Member

Apr 6, 2011

10,739

6,721

214

Hillsborough county

Jul 3, 2016

#2

• Jul 3, 2016

• #2

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

11,606

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In the garage

Jul 3, 2016

#3

• Jul 3, 2016

• #3

did you notch the bracket for clearance for the 3g alternators? No it should not be resting on the back of the bracket.

 

fox-gt

Member

Feb 28, 2004

204

0

17

TN

Jul 4, 2016

#4

• Jul 4, 2016

• #4

I notched the front, not the back.

 

mikestang63

SN Certified Technician

Aug 27, 2012

11,606

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In the garage

Jul 4, 2016

#5

• Jul 4, 2016

• #5

does the alternator turn freely in the bracket or does it hit? You need to grind away any interference.

 

Shakerhood

20+ Year Stangneter

Oct 28, 2004

3,356

208

114

Ohio

Jul 4, 2016

#6

• Jul 4, 2016

• #6

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

204

0

17

TN

Jul 4, 2016

#7

• Jul 4, 2016

• #7

It is clearing now.


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

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,257

17,941

224

Massachusetts

Jul 5, 2016

#8

• Jul 5, 2016

• #8

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.

 

Reactions: 90sickfox

90sickfox

Wasn't a pretty sight...and I've got big hands

SN Certified Technician

Mar 2, 2015

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Jul 5, 2016

#9

• Jul 5, 2016

• #9

Glad you found the problem [emoji106]