Sometimes when I start my car, there is a low pitch buzzing coming from the passenger side of the engine bay. The higher the rpm, the higher the pitch/frequency. It has been going on for about 2 weeks now and a minor belt squeal has decided to chime in today.
I asked my mechanic last weekend, and he suspects the alternator or water pump may be getting ready to die.
So before I drop money for troubleshooting, I thought I would seek your opinions from the few details I can provide.
Any suggestions or ideas would be appreciated.

 

Do you have an after market sound system in the car?
Sometimes that also causes a high pitch noise.

 

Could it be a heater?

Mine makes a sound when its on, on the passenger side

 

turned out to be a bearing in the AC condenser. A bit o lube cured the noise. Got the belts chaged while she was up in the lift too.

She sounds much better now!