ACDelco92191127 GM Original Equipment Alternator

This fit/worked for my 09 G8 GT.Get this OEM Replacement part and don’t even mess with aftermarket manufactures or Remans.The original alternator failed at 244k miles and was replaced recently with an Ultima Reman. It lasted less than 6 months and 7k miles.. Headlights would intermittently FLASH, not a slight surge but flash bright and then super dim. Monitored voltage and it spiked all over from 13.3V to 16V. Anything over 16V and the BCM kills the dash lights, radio, etc…Replaced with this GM part (It’s manufactured by Mitsubishi for GM, just like the originals. They are the ONLY manufacturer that has the specs that the G8 requires. The alternator is internally regulated but the ECM regulates the field winding. The aftermarket regulators are not to spec and voltage will be all over the place and the BCM does not like it)It has the exact same labeling, identical in appearance regulator and wire stud, etc.10/10 would buy again and again. Cheaper to source here than 500$ from the dealer.Saw multiple complaints in other reviews.1. No weird through the fender well/from the bottom stuff is required. Remove the idler pulley and then the 3rd bolt for the Alt bracket and the alt comes right up in between the WP and PSP.2. Zero grinding to get it to bolt up… the bracket has floating spacers in it that adjust up as you tighten the bolts. Put the bracket in a vice with a socket and drive the spacer out(loose) then assemble and tighten down and all will snug up together.Good luck!

Perfect

Loud Whining noise after fitting returning

Great

I had the original alternator in my '09 G8 GT fail. This one worked perfectly in its place, and appears to be a legitimate OEM replacement (it came in a box branded Mitsubishi, which I believe is the OEM supplier). No complaints whatsoever, and well under half the price of the exact same one ordered through a local GM dealer.