Is it the power steering pump or alternator?

[idosubaru]

SOHC EJ25. Got a light chirping noise - like bearing-ish from either the alternator or power steering pump. Fluid in the pump appears fine and with a mechanics stethoscope I really can't tell. I place the probe on the front and back where the shaft would be and don't hear anything confirming from either one.

 

No symptoms, steering and revving the engine don't add or change anything.

 

Anything else I can try?

[john in KY]

When my alternator bearing failed a few years back I first noticed that chirping sound. Noise got progressively worse over a two week span. When the bearing is on its last leg the alternator will be too hot to touch after just a short drive.

[Rooster2]

There is a tensioner pulley that one of the fan belts uses. In the past, I have had the bearing go bad in that pulley.

[idosubaru]

thanks rooster, i forgot to mention I put the stethoscope on that pulley as well and got nothing. it seems closer to the top and likely the p/s or alt - but with the engine noise and my weak hearing it very well could be one of the three.

 

so thanks for complicating this!

 

i guess the easy thing to do would be to swap that pulley first then alternator second. both of those are really easy.

 

*** are SOHC and DOHC alt's interchangeable?

 

p/s pump isn't hard just annoying with the fluid and all.

[lmdew]

Pull the belt off does the noise go away?

 

When the belt is off, check the pulleys/bearings for any roughness.

[ShawnW]

Usually for me when I cant narrow this down its the power steering pump.

 

I have taken the belt off my GL with 2.2 swap and put that on the crank pulley and alternator alone. If the noise goes away its narrowed down to the ps pump or the belt itself.

 

If its the pump it can be because it has an air pocket in it. Sometimes raising the reservoir and pouring a tad more fluid in than the full line before/after doing so will clear up the noise. Sometimes I loosen the pressure side of the pump and bump the starter over with the coil pack disconnected to try to "prime" it. Has also worked but rarely.

[Caboobaroo]

It seems to be common for the alternator to start chirping. Seen it quite a few times on high mileaged EJ Subarus. Bearings are starting to make noise and before too long, the alternator will quit working.

[idosubaru]

swapped the belt tensioner and alternator and appears the noise went away.

 

the chirping decscription is exactly what this one was doing.

[Caboobaroo]

I bet if you spin the alternator by hand and listen carefully, you'll hear it squeak. Reason why it would be louder while the car is running is because of the tension the belt puts on it.