Replace Alternator? ( Update Engine Noise)

There was a whirring sound coming from my engine. I figured out it was probably because I had run a 1500 watt power inverter off the battery powering a 1450 watt device. I tried again and a similar noise came from the engine compartment.
The battery shows 14.3 when engine is running, 12.7 at test. So question is do I need to replace alternator because of the noise even though the battery shots a good charge? Nearing 200,000 miles.

 

I hope my recent issue can solve part or all of your problem.I slowly started getting a blower/gear whine that mostly showed when warmed up.I stethoscoped the alternator and bearings were gone and it sent that sound throughout driver side valvetrain.I have 230,000+ miles on my 2002 3.4 Tacoma and the alternator was stock.Let me know if it helped!

 

I'd look at your idler pulleys, remove the belt and spin each one to see if it turns freely. Don't look at the expensive stuff before you check the cheap stuff first.

 

If your alternator is under a load it's going to whine. That's normal. You put an inverter on it and the noise is there. Your voltage read outs are all normal.

 

Yes volts are still normal. But sometimes I get the whinning noise when no load is on it.

 

If the battery has discharged at all (which is likely the case running a high wattage inverter on it), then you will hear the whine for a bit and it will go away when the alternator is done topping off the battery. This is not uncommon. If I leave my lights on for a period of time and start the truck, the whine occurs for a few minutes until the battery is fully charged again.

 

The inverter was a 1500 watt and 1500 watt load.Too much for this truck. Installed new battery and it's back to 14.3 when at normal idol. I'm having the alt checked anyway. It was whining on me when I was in the middle of nowhere.