Whistle from engine area after engine stop

[andrew-amazing]

Hello everyone,

I noticed recently that after stopping the engine, there is whistling coming from the engine block.

I am attaching the video, please let me know what could generate this noise.

Thanks in advance,

Andrea 

[Colinb623]

Are you running your aircon ? My IS300H has done this for the last 2 years after shutdown if I have been running the aircon on a long journey.  I think it's normal 

[andrew-amazing]

Yes as always, but it started making this sound just few weeks ago.. It makes the sound even at cold engine if I stop the engine after 30 seconds.. Don't think the variable of the long journey works as hypothesis.

Can't understand from where it is generated

[andrew-amazing]

Apparently it's coming indeed from AC. I tried to not use the AC few minutes before arriving home and after the engine is shut down it is no more making noises anymore.

 

Contacted local Lexus dealership and they said it's normal, also happening for other models. It's due to the coolant fluid used in the AC system that is pushed by the compressor after the engine stop. In summer the system is more under stress compared to other seasons, that's why it appeared just recently.

 

 

[Colinb623]

Also on this , mine is louder in warmer weather so it all adds up 👍

[stepppy]

Mine does this too, it was just the same in my Prius.