I drove my car for 15 min, then started noticing a whinning sound that gets higher pitched with engine speed. The exhaust sound covers it up past 2500rpm. I got out my stethoscope and poked around but cant pinpoint it. What components might make a whinning sound?

 

With the car running I loosened the belt tensioner some. The whining sound got quieter, but not gone completely. The pulleys were still turning, but slower, so it must be comming from one of the pulleys. I dont think the A/C is making the sound and I believe the water pump makes a squeal when it going bad? So do the Alt, PS pump, or Smog Pump ever make a whining sound? PS fluid level is good, so its not just low on fluid.

 

I was searching on camaroz28.com and someone there had their alternator making the same whining sound. But my gauge always reads 13-15 volts. Is this first first sign of dying alt? I wouldnt be surprised since its 16 years old.

 

Um, my mom's Subaru kind of did the same thing. Check every pulley while the car is running and make sure that NONE of them are wiggling at all. Like, you shouldn't be able to tell if they are turning or not because they are supposed to be that straight. The slightest wobble could mean that a bearing in the accessory is shot and needs replacement. Check it out.

 

my experience is that the ps pump will squeel really badly if it's on it's way out, even with it full of fluid. we had one on my buddies car that was whinning really badly, but it was still full of fluid. we replaced it and the whine went away.

 

the noise sounds like a centrifugal supercharger. Its a pure "whine" sound, not a squeal, very distinctive and changes tone with the slightest change in engine speed.

 

Well, you are right that it is a pulley accessory, since it changes with RPM, unless its something really effed up inside the motor, but I have never heard anything like that from inside a motor before. I think you can rule out the AC since that only engages when it is turned on. That leaves you with water pump, power steering, smog, and alternator. You should be able to narrow down which accessory it's coming from by just listening to each one with the hood open. Rev up the engine from the throttle if you need to. I don't see why you wouldn't be able to single it out.

EDIT: Wait, I'm reading your first post again...you said that it started 15 minutes into driving. Is that EVERYTIME you drive, that it starts 15 minutes in, or like, did it do that once, and now it does it from square one when you start the engine?

My mom's subaru does the exact same thing...fine on startup, but then 20 minutes later...shabang. Everytime. One of her pulleys is wiggling which is causing that squeal...so yeah, check that out.

 

I had the very same problem last year. All of a sudden my engine developed a high-pitched whining sound. To make a long story short, it was the alternator. Replaced it with a new unit, sound went away. End of story.

 

unless the whining gets annoying, Im gonna leave it alone, since the alt still does its job properly. If it gets louder without changing its tone at all people are gonna think I have a supercharger

 

That's what I did, it went another month or two before it quit charging. Keep an eye on the batt/alt gauge.

 

is this whining louding in parking lots? i got this too. check your power steering fluid! mine has a leak in the power steering reservoir and makes a whining sound when it runs out of fluid.