sounds like a flourescent light when it's too cold
I was kinda wondering that same thing, but when I installed them back in October, the weather was still quite warm and they were doing it then.
James Shafer
2003 GP GTX SLP P/N 50066 (SOLD )
2005 Nissan Pathfinder SE 4x4 (The baby hauler )
St. Louis MO
1.9 Modified Rockers, TOGs, 180 Tstat, PRJ 10.4 Wires, P/P Gen 3, SLP Ram Air Hood/Wizaired CAI, Gen 1 Spoiler, 3.4 ZZP Pulley, Desert Fox Tranny Cooler, Thrasher Shift Kit, 18" TSW Mondellos w/ AGX Struts, SSC Gen II Springs