Just a shot in the dark, but have you checked your cabin air filter under the passenger side of the wiper cowl? They tend to plug up and can cause lack of air flow.
Sounds like a cam phaser. They run off of oil pressure, and at low rpm/idle maybe your oil pressure is dropping too low, caused by a weak oil pump. Need to check oil pressure with a mechanical gauge.
Have all the plugs out, pull fuel pump relay and crank the engine over. 170psi of cylinder compression will blow the pieces right out. I've done tons of them at the shop I work for and works every time.
Bearing can pit out along with the races, making the noise. Seen it a lot on dodges and jeeps lately. New bearings and races and check your clutch packs and new fluid with friction modifier, you'll be good to go.
Medium speed can - (Pink/Orange) pin 14
Medium speed can + (White/Orange) pin 15
Medium speed can wires to the SJB pins 50 and 51
High speed can - (Pink/Light Green) pin 17
High speed can + (White/Light Green) pin 18
3 stages
1st stage - Tighten to 2Nm (18lb-in)
2nd stage - Tighten to 10Nm (89lb-in)
3rd stage - Tighten an additional 45 degrees
Tighten from center outwords and don't forget the silcone on the front cover and crankshaft rear seal retainer plate to block sealing surfaces
+1 on the fuel pump. TSB on it after crusing at highway speeds and comming to a stop/slow down and then accelerating again. Had the same problem, changed out with the updated unit, haven't had any problems since.