[Slims335]

Hey guys first post here, but I recently got a 2008 e92 355xi and sometimes when put the key in the car gives me the chime and the radio works fine, other times I put the key in and I have no sound at all, no chime no radio NOTHING, today I was out and the sound was working perfectly but when I got back to the car and put the key in the car just started blaring like sorta static but it wasn't real static it was just LOUD like it was giving me the chime but very unclear and loud and it doesn't go away unless u mute all the sound in the car, its the first time this has ever happened to me and the guy I got the car from said its only happened to him once before and then it went away after letting the car sit, so hopefully it goes away but I was wondering if this has happened to anyone before and if anyone has a fix for the sound sometimes not working.
(i do have a video of the noise but i don’t know how to insert it into the post)

[ctuna]

Check for water on the amp and a low main battery.