Alternator question?
Anyway, looks just like the stock one (except with a gold pulley and the middle piece is gold too). Install went fine 2 nights ago, sounded a lot better with no squeaks or other unwanted noises. Last night when I started it up (which was almost 24 hours since the last time it was running so it was very cold), the alternator was making a weird "scratchy" sound, and also sounded like "shot" bearings. The noise only happened for the first 30 seconds of running, and did not return for the rest of the time driving. I then tried it this morning and the noise was not there. Left it to cool off all day, and tried it tonight and the noise was still not there.
Any ideas why a brand new alternator would make a strange noise the day after install for just 30 seconds? Thanks!
EDIT -- I would also like to add that the plastic fins on the fan look as if there is almost no play between the fin and the case, when compared to the old alternator. So I am wondering if the plastic pieces expanded/contracted just enough for them to rub on the case for that little bit, and wore it away which is why the noise has not returned.
Last edited by Jeff 97 Formula; Jan 20, 2012 at 08:03 PM.
Is it possible that the new alternator just needs to be "broken in"? I'd really hate to take it off and bring it back just to be told "nothing's wrong with your new alternator". Thanks!
If its working and its quiet, drive it for awhile. I've always gotten Lifetime warranties at PepBoys....so I bought my first replacement alternator for like $120, and I've returned it once for a free replacement. When this one goes I'll go get another free one. That deal can't be beat. But two alternators in 14 years, I'd say they're pretty good units. especially when its just a 15 minute job to swap them out.
.
best/easiest thing to try in my opinion is leave it installed, pull the belt off it, and spin the pulley by hand. feel for any bind. also check endplay by pulling the pulley fore and aft, if you can shift it fore and aft a significant amount that would explain the fan rubbing noise. alternators are pretty simple mechanically, if it only did it once then maybe the noise didn't come from the alternator, or the belt shifted on the pulley or something.
best/easiest thing to try in my opinion is leave it installed, pull the belt off it, and spin the pulley by hand. feel for any bind. also check endplay by pulling the pulley fore and aft, if you can shift it fore and aft a significant amount that would explain the fan rubbing noise. alternators are pretty simple mechanically, if it only did it once then maybe the noise didn't come from the alternator, or the belt shifted on the pulley or something.
I've been keeping a close eye on it and remembered when the noise happened the fan blades looked as if they were touching the housing. Since I haven't heard strange noises after that and it works fine, I left it alone.
Today, I now noticed the blades are 1mm away from the housing. I took the belt off, the alternator is spinning freely with absolutely no binding. I also tried (as you suggested) to pull the pulley fore and aft and there was no noticeable play). Still working fine with no noises, but I don't know what to do at this point.
good read on alts.....and why rebuilds are a crap shoot
Trending Topics
good read on alts.....and why rebuilds are a crap shoot
The Best V8 Stories One Small Block at Time






