Strange noise when you shut the engine off

[gpjlytham]

My wife drives a 2011 Genesis 4.6L 130k miles. I drove it today and when i shut the engine off it makes a funny noise, it sounds like something is rotating and the bearing is going bad. No engine lights or codes showing. It appears to be coming from the front of the engine but I haven't had time to find my mechanics stethoscope.

1st thought was the radiator fan was going bad, but the noise is still happening after the fan has stopped rotating.

2nd thought was something attached to the drive/serpentine belt was going bad, a guide pully, tensioner, a/c, alternator etc. but the noise continues after the belt has stopped rotating.

I leave early tomorrow and i'm not back until Fri eve so I cannot do any more diagnostics until next weekend but I thought I would reach out to everyone on the forum to see if anyone has any idea's.

My wife will be using our spare vehicle this week to stop any potential damage to her car.

 

[gpjlytham]

Update:- I used my mechanics stethoscope and it was the alternator making the noise. When the drive belt stops the internals of the alternator keep spinning and therefore the noise after the belt stopped turning. I had replaced the alternator 4 years ago. i bought the part from autozone and they have a lifetime warranty so they gave me a new one at no charge. But..... the alternator isn't easy to remove. I have 2 manuals and both say you unbolt it and it comes out but that doesn't appear to be the case with my car. The alternator is in a cradle that is bolted to the engine and the cradle needs to be removed to get the alternator out. 2 bolts holding the cradle are behind the alternator making them difficult to get out, you also need to remove the engine oil dipstick tube and removing the air filter box and inlet tube makes life easier. A free fix.

 

[Lug-nuts]

Was the alternator your problem? I have what sounds like a wheeze about 15 seconds after I shut if off, and everything has stopped. Its really weird. What did yours sound like?

 

[gpjlytham]

Was the alternator your problem? I have what sounds like a wheeze about 15 seconds after I shut if off, and everything has stopped. Its really weird. What did yours sound like?

Yes the noise went away when the new alternator was installed and hasn't come back.