[Tdenardo218]

Video posted on YouTube with description of what's been done to diagnose so far. Please help!

Ok, I've been tracking this noise for the longest time. Here's what I've got:
Only happens with the ac off. Car has to be normal operating temperature. Noise goes away when the ac is turned on. When car is warm, it is worse when starting and not running the ac. Run the ac for a few minutes (noise goes completely away) and turn off and the noise comes back, but is better, but not gone. It's very hard to determine if it's related to the ac or not. Second bit of information:
I have used a stethoscope on everything. Block - normal, head - normal, power steering pump - normal, alternator - normal, idler pulley replaced and normal, tensioner replaced and normal, ac compressor - normal (has electric water pump and that is normal. I put the stethoscope on the expansion valve and noise is heard loud and clear there. I replaced the expansion valve and noise still exists. I pulled the cowel and found a brake line against the high side line along with the high side line against the firewall. Light tap of the brake line on the high side can be heard loud and clear with stethoscope on high side. Cushioned brake line against high side and moved rubber grommet to high side against firewall. No noise can be heard on high side. Noise can be followed from expansion valve down low side line. Put car in air today and found a few items against low side line. Secured all items away from low side line. Low side is bolted to engine in 2 areas. Sound can be heard resonating in car, but not outside unless using stethoscope on expansion valve or low side line. Im wondering if sound is resonating through the low side from engine?? There is a new compressor in the vehicle (import direct). The old compressor had a sticking swash plate. Here's the interesting part. I had the same noise before with the old compressor, but it was when I turned on the ac and happened until the swash plate released and then the noise would go away. If I kept the ac off with the old compressor, it would be silent. I am at a loss.