Hello everyone, I have recently purchased (last week) an is250 2009 with 118000kms its just started making a kind of electric motor whine when I start to accelerate, I was wondering if anyone would be able to help and tell me what it may be? It sounds like it's coming from the engine and it only seems to happen in drive. Also not sure if this is related but theres a sound in the cabin that I heard for the first time this morning that sounds like a camera lens focusing, any help would be much appreciated! I would try get a video of the sound later
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It's most likely the alternator making the whining sound

Here is a video of the sound

Here's a better video