My car (mods in sig) has a LOUD whine that is engine RPM related and occurs whether or not the car is in gear.

It just started this today. I thought at first the alternator was going bad because I'm also getting low voltage with the voltage in the yellow zone constantly but rising and falling with the RPM.

I think as far as the whine goes, the voltage drop might be a red herring because I took the belt off and spun the alternator by hand and it didn't make a sound that I could tell, but I couldn't spin it fast at all.

Also, I spun the water pump by hand and it moans when you turn it the way it is turned by the engine. I just replaced the water pump almost exactly a year ago, so I don't see how it could be bad already unless it was a POS reman job. The old one was leaking so I put this one on a year ago. The current water pump is not leaking that I can tell.

I also ran the engine for a few seconds without the serpentine belt on and it was dead quiet, so I know it's NOT something internal in the engine.

Could leaking coolant from the water pump be dripping on the belt and making it slip and make it not turn the alternator enough?

I was out of town for the past 4 days and the car had been sitting for that period of time and it has been raining a good bit here for at least the past 2 days. Could that have something to do with it?

What's going on here?

 

alternator turn smooth? should turn easy

 

Yes, it turns smoothly as far as I can tell. It feels just like any other alternator I've ever spun.

It does not sound like a power steering pump going out. The noise is still there even when the steering wheel is straight. It is LOUD and sometimes changes pitch at idle (up the octave).

I need to check the power steering pump though. It might be cavitating and making that noise, but I'm not sure.

 

you stated the water pump is leaking coolant, if so that's your problem.

 

the OLD water pump that I replaced a year ago was leaking. This one isn't. At least not that I can see.

 

how many miles on the pulley ?the groves the belt rides in can wear larger ,not grabbing the belt to good.

 

how old is the ac belt?

 

It's not the AC belt because with the serpentine belt the noise stopped. I'm going to take a better look at it tomorrow.

 

TTT for update

I charged up the battery to full and drove it again today. Still whines and voltage is still dropping. I bought a new belt a while ago but it got lost when I moved apparently. I'm tempted to pull the alternator and get it tested.

I'm also going to go ahead and get a new water pump and put it on which I know is a PITA because I did it almost exactly a year ago and that POS water pump that I put on is going straight back to the factory.

That pump that is on there now has a lifetime warrantee on it, so would I be able to get $$$ back for it?