- Aug 19, 2014
- 83
This morning, my 04 Bravada started this whine noise that i cannot figure out! I've had a scope on all the pulleys, changed the idler as it is normally the culprit.....nope!
I took the serp belt off and started her up......whisper quiet.
SO its definitely something with a pulley/or belt related.
Here is what i've done to try and figure this out:
- Changed the idler pulley.
- With belt off, i hand spun all the pulleys. No gritty/grinding noises or feel at all.
- Scoped/hose tested every pulley (Water pump, alt, tensioner, etc) all are quiet.
- Took bravada to two different shops. They cannot narrow it down either.
- Its RPM (low rpm) noticeable very easily. You can easily hear it at idle.
- Sound increases with small throttle imputs and then goes back to a "whine" at idle.
- The water pump and clutch fan were changed last fall.
- The water pump is tight. Zero play. I dont suspect either the fan/WP.
One shop suggested it might be the alternator on its way out. Even tho you cannot hear anything with a scope.
Again, this just started this morning on startup.
No codes, and nothing pending either.
It 'kinda' sounds like a power steering pump on its way out just to give you an idea of the noise. By the way.....i checked PS pump and fluid. Both are good.
Any ideas?
I took the serp belt off and started her up......whisper quiet.
SO its definitely something with a pulley/or belt related.
Here is what i've done to try and figure this out:
- Changed the idler pulley.
- With belt off, i hand spun all the pulleys. No gritty/grinding noises or feel at all.
- Scoped/hose tested every pulley (Water pump, alt, tensioner, etc) all are quiet.
- Took bravada to two different shops. They cannot narrow it down either.
- Its RPM (low rpm) noticeable very easily. You can easily hear it at idle.
- Sound increases with small throttle imputs and then goes back to a "whine" at idle.
- The water pump and clutch fan were changed last fall.
- The water pump is tight. Zero play. I dont suspect either the fan/WP.
One shop suggested it might be the alternator on its way out. Even tho you cannot hear anything with a scope.
Again, this just started this morning on startup.
No codes, and nothing pending either.
It 'kinda' sounds like a power steering pump on its way out just to give you an idea of the noise. By the way.....i checked PS pump and fluid. Both are good.
Any ideas?
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