[OG68]

X2.
I had an unusual noise from the front of my '07 Cadillac. Most noticeable whenever the AC compressor was pumping. Dealership replaced the compressor but discovered that wasn't the cause. A senior mechanic, "the old guy", as my service advisor put it, opened up the inspection cover and discovered a cracked flex plate. Evidently the compressor put a slight load on the crankshaft to enhance the noise.