Odd BOV type sound from under car?

[DTR rex]

I would avoid using it at all costs see if you can save it. I would get in contact with an ac repair shop and have them test/charge the system.

Is there a way to determine what exactly is wrong with it?

My buddy (who is a mechanic) said that it could be the pulley. The belt was recently replaced so how do I know if the system is (a) going completely bad and I need a new A/C compressor (b) have a bad pulley or (c) need a recharge?

[T0rque]

I don't think the Subaru ac compressors clutchs (pulleys) are serviceable. If you take the car down to a certified ac shop they can tell you if your car needs recharged or not.

[DTR rex]

I don't think the Subaru ac compressors clutchs (pulleys) are serviceable. If you take the car down to a certified ac shop they can tell you if your car needs recharged or not.

What does it mean if they're not serviceable? They can't be fixed and thus the whole unit must be replaced?

If so, how much does that usually run?

My buddy usually does all the work on my car. Is that a pretty straight-forward replacement?

Forgive my ignorance Bo.

[SD_GR]

Ok, it looks like it's the A/C compressor.

Or its clutch, or the other pulley. The prices vary wildly, since the other pulley is $20 whereas the compressor itself is hundreds.

Do I need a new compressor?

Remove the belt and see if the pulley (not the clutch on the compressor; the roller that's independent) spins freely. Also double check the belt itself.

A recharge?

Get some gauges on the system. Interpretation is a skill but in general high pressures may result from overcharge or poor cooling problems and low pressures from leaks or bad refrigerant flow. If you do need a recharge find and fix the leak, since you should not be losing refrigerant. Look for oily residue anywhere in the system, including on the hoses themselves.

The only thing that worries me is that sometimes the car will very slightly jerk when the noise comes during acceleration.

This could be normal when the compressor is engaging.

What does it mean if they're not serviceable? They can't be fixed and thus the whole unit must be replaced?

Yes.

If so, how much does that usually run?

Removing the compressor and replacing it is a bit more complicated than r/r the alternator since it has tubing and is a pressurized system, but not much more complicated. The part is expensive but you can find a wreck usually (thanks kids!).

My buddy usually does all the work on my car. Is that a pretty straight-forward replacement?

Yes. Keep the lines clean and use new o-rings (if possible...). Find someone that knows how much refrigerant and how much lubricant to use. This person will typically be able to drain the system before opening it up anyway. You will also need to pull a vacuum once it's all back together before refilling it.

All this assumes your compressor is bad, and we don't know that yet though. Stay optimistic until you find out for sure (worrying gives people wrinkles).

[DTR rex]

Thanks a lot for the info guys!

I replaced my belt about 3-4 months ago so that should be fine. Also, I checked the pulley and it seemed fine (no lateral movements and spun fine).

I'll check the pulley again and see if a re-charge is necessary. If both of those things seem fine the I guess I should assume the whole compressor needs replacing?