By the way, they said they drove around other GX 550s and also heard it. I have an OT. It wasn't clear to me whether this is an issue in other versions or whether they only tried in other OTs. I asked my mechanic (I bought through their business) but the Lexus dealer is the one that performed...
I got feedback from the dealer today. They heard it too. They said it's an expansion valve cycling during AC operation. They said they are treating it like normal operation and there will be no fix. Honestly, I may have to sell this vehicle because it annoys me that much. I love everything...
I am definitely having this same issue. Any advice on how to escalate to Lexus?
I only hear the hissing sound when the AC is on and I am driving. I do not hear it when the vehicle is in park, for example, or when the AC is off. It is really annoying and I can hear it over music. I would...