Hi Scotty, I know you love your Lexus so maybe you can help me with mine.
2018 Lexus NX300 F-Sport 2.0 Turbo, 6-speed auto. 33,000km/20k miles.
There is a loud buzzing on the passenger side engine bay, I've taken it to the Lexus dealer and they said: "No codes, No problem, maybe they all sound like that?"
The noise is like an electrical transformer buzzing and it's quite loud.
I've attached a video of the noise, let me set up the parameters.
A/C is off and has been for 24h, HVAC fan is off, Radiator cooling fan is not on/running in video. Temp is 20C/68F
https://www.youtube.com/watch?v=zrxd1p4blmw
In general this engine is known for making quite a lot of weird sounds...
Although this probably isn't related to your issue - what you should know is that a very common fault to occur at your millage is water pump failure so keep an eye out to not overheat the engine.
Looks like I've found the answer in an old Lexus forum post. Seems to be the VRV Valve (Vacuum Regulating Valve for the turbo wastegate).
Thought I would put it here to help others.
https://www.clublexus.com/forums/nx-models-2015-present/868375-is-this-engine-noise-normal.html
Thank you for sharing the fix!
I might as well add the TSB in here too. https://static.nhtsa.gov/odi/tsbs/2018/MC-10152179-9999.pdf
Is your fuse box in that area? Could be a faulty relay buzzing.
Fuse box is on the drivers side behind the battery (other side from the noise). All the belt driven components are on the passenger side of the engine. Dealership says its not the alternator....