illitirit

My 2004 GX470 with 130k miles on it recently when the A/C is on at no matter what temperature exhibits a high pitch noise that is really annoying. Sounds exactly like coil whine from a electronic device / capacitors.

Turning the A/C off immediately remedies this situation.

Could someone tell me what part of the car this is caused by and would it be easy to fix myself? I'm pretty handy, but I dont know much about cars.

chiph9

Check the easy stuff first - make sure your cabin air filter isn't clogged.

Also, does it change pitch when changing the fan speed?

Chip H.

Organized Garage Status

I can almost bet it's the alternator. Mine did the same exact thing before it died. It's on its last leg so be ready if it suddenly goes out, you might get stuck somewhere.

illitirit

I changed the cabin air filter last week so it cant be that.

I tested earlier and the high pitch noise is actually most present at low to low/med speeds. However, I feel like from medium to high, the noise is the same its just I hear way more fan noise so it drowns out the high pitch noise.

illitirit

Could you tell me how much an alternator costs to service?

And is there an easy way to check how its doing or is this a job for a mechanic?

maxx430

You can pick up an alternator for about $150 at you local auto shop (Autozone). The labor is not difficult. Youtube on how to check the alternator. I have checked mine with a multi meter. There should be an indicator light if it is going bad.

sheikhmax

Just recently some people including myself had the issue. If your ALT Bearing is on the way out it would whine and make loud vacuum noise but it will still charge the battery ok and voltage will not be an issue. Have a read on the thread below as it might help:

https://www.clublexus.com/forums/gx-...uum-noise.html