[Drewy]

Hey guys,
I have a B8 2008 S5 4.2 and occasionally I get a really noticeable whining/humming noise when I start the engine - particularly from cold. It is directly related with the RPM of the engine and goes away after about 10 minutes.

I've tried to capture it on video HERE (Google Photos Link)

Any suggestions?

 

[nigelbat]

Sounds like a bearing. Can you check the ancilliaries?

 

[Alex1990]

Definitely a sound from the engine bay. I personally wouldn't say its from the engine but I can hazard a few guesses:

-failing water pump
-bad power steering pump/low power steering fluid
-failing alternator
-failing AC unit

The list could go on tbh...
Hope this helps! If you can locate the EXACT or atleast minimise the sound location, you'd be better as crossing off more from the list really.


Hope this helps,

~Alex

 

[Alex1990]

Sounds like a bearing. Can you check the ancilliaries?

Bearings will tend to hear a tapping sound if it's really worn. Can definitely be a whine too but I'd be more inclined to say a that if the engines main bearing is going there'd be a rougher idle the engine itself would physically shaking more and also the tapping too or rod shudder.

~Alex

 

[jnrdavo]

Water pump at a guess.. can you isolate rhe sound from rhe engine bay when you open rhe hood?

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