2nd gen IS350 [2GR-FSE], is my engine sounding healthy or there’s something amiss? The engine has gotten slightly noisier lately coincidentally it’s been getting really cold too, could that be the cause?

I have done a lot of maintenance and I’ll be a shame if now I have a major issue with this engine, engine feels smooth and powerful, I have recently done valve cover gaskets, spark plugs, spark plugs seals, serpentine belt, coolant flush, transmission fluid, water pump.

 

Sounds fine to me. Mine is about to go into troubleshooting since its making some unwanted noise that i cant explain really. I can send a video here later, so you can hear the difference between our engines. Yours sounds fine to me, the cold in my experience makes a difference up until the engine has warmed up. How much did you spend on the maintenance you mentioned?