I have a 2016 1500 6cyl I picked up in Jan. used. Hot weather hit last month so I turned on the AC for first time... Not cold. (I bought it in Jan. so it felt cold then...I'm in PA). So still low miles under warranty, fixed. But like 2 weeks later I notice I have a surge/shudder/vibration when AC is on and usually at idle. They think compressor... New compressor... Nope. So I get a call today saying they're going to compare it to 2 other 6cyl in the lot...I guess if they do the same thing it's the nature of the truck, here's your truck back. I have a hard time swallowing that thinking. So is that normal? Do you 6 cyl later model guys have it?