Loud Clicking Noise on Cold Start

[lexustrey]

I’ve chased this down for almost two years, at dealer, independent, online, etc. with no satisfaction yet.

2015 LS 460L 197,180m

The car runs perfectly, except when starting after long sit. 

At that point, after start, the engine slowly builds a clicking sound, then cycles and starts over. This continues for 3-5 minutes. During the “buildup” of the clicking, the engine appears to “bog down”, then “relax” when the clicking stops. 

[Bykfixer]

Sounds like lifters may be sticking.