ive noticed with the weather getting colder that my alternator belt is kinda loud. its kinda between a squeak and a grind. maybe not a grind but not a full on squeak if that makes sense. any thoughts?
okay new symptom. i may be my alternator making the noise but it kinda just sounds like a supercharger winding up with the rpms. its not super loud but i can notice it.
If you have any tools,take off the belt and spin the alt. by hand.It should be very quiet.Just a hint of rotational noise.Or you could just tighten the belt up and see if the noise goes away.
Make sure your power steering is topped off. It can create a whine. Try moving the steering wheel side to side while it is sitting still and see if the noise changes. Check the tension pulley on the AC as well if you determine it does not seem to be anything from the alternator belt. Try squirting it with WD-40 while it is running. If the noise goes away, REPLACE the pulley. Napa has them pretty cheap. More than one person (myself included) have had those grenade.
I had a WRX wagon come into the shop last week with that exact same problem, it was in for a clutch, but I noticed the alternator whine when I started it up. Somewhere between a whir and a buzzy kind of noise. It was loud, but After about 5-10 min of driving on the test drive, the noise had quieted down. Unfortunately, the customer didn't want us to troubleshoot it...my boss speculated that the diode packs could have been failing. The only reason I give that a mention is because he described the symptoms of a failing diode pack before I told him what the symptoms were on the car...He described it as a whine that goes away after a few minuites. Other than that, I really can't offer any help other than what has already been advised.
My 92x and STI both have some belt squeal on start when its cold or after I wash them sometimes. I took the STI to Troncali the day before the Subaru Challenge last year and they found no issues. Ped and I looked at it once also and couldn't figure it out other than tightening the belt a little
your noise description is spot on, that is exactly what it does, i havent been recently driving the car until the afternoon when it is warmer outside and unless its really cold outside it wont make the noise. so im guessing if the diode pack is failing its time for a new alternator?
Yeah...but I would check the belt tension, and the pulley for noise also. If you have access to a volt meter, it would be a good idea to see what kind of a charge the alternator is putting out. To do a proper voltage test do the following four steps... 1. measure "base voltage"...check the voltage with the engine off. 2. measure "no-load voltage"...check the voltage with the engine running and accessories off 3. measure "load voltage"...check the voltage with the lights/ac/wipers/interior lights...etc...on 4. measure "charge voltage"...load voltage - base voltage = charge voltage. Charge voltage should be .5 volts higher than base voltage. You preferably want to do this when you are experiencing the noise, and then again once it goes away.