2011 bmw 335ix N55 engine howling noise. Even just ignition on & engine off

What is your question?

My 2011 N55 335ix started making a strange sound from the engine intermittently and now it is becoming more frequent. Af first it would do it when I turned on the heat. Now it is doing, although a lot less frequent, as even when the heat is not turned on. I have changed the battery thinking that the 7 years old battery might be dying. That noise is still there. There is no warning light on. I bought a scan tool, plugged it in and switched only the ignition on (engine off) to do the scan, while doing that the strange noise from the engine started doing it! It would repeat about every 4-5 seconds. It seems to be getting worse, from just doing when driving and having the heater turn on once in while, then it became more frequent, and then it is doing even without the heat on, now it it doing even just the ignition on (engine off) and connected to a code reader/scanner I have checked and it does not come the belt, pulleys and fan. Does anyone know what the cause of this problem is?

What makes this problem better or worse?

Don’t know yet

How long has your 2011 BMW 335i xDrive had this problem?

A few weeks now