A/C makes loud noise (rpm-related)

[ILoveMPower]

When I'm driving with my A/C on (err, the snowflake :P), I'll sometimes notice a kind of grinding/buzzing noise coming from the engine bay. Now I understand the ac has to make SOME kind of noise, but this noise doesn't make the sound of BMW refinement.

If I have the radio off, and notice the noise while cruising at say 2.5-3k rpms, as soon as I push the clutch in the noise immediately stops (or at least grows too quiet for me to hear).

Any help or input is much appreciated!

[BillionPa]

compressor bearings.

there is a clutch that disconnects the compressor from the drive belt pully when its off, so the sound is inside the compressor.

[ILoveMPower]

compressor bearings.

there is a clutch that disconnects the compressor from the drive belt pully when its off, so the sound is inside the compressor.

how difficult is it to replace these? also approx how much $$?

[BillionPa]

i dont know if they are fixable, usually the compressor is replaced.

[joshua43214]

The compressor can make noise if not properly charge too, I would check the bearings first, the clutch assembly can be replaced without dischargeing the AC, but most folks replace the whole compressor since its often not much more.

[BillionPa]

indeed, low charge, which contains the lubrication oil, is a major factor in AC componenet damage.

[ILoveMPower]

so how much can i expect to pay to get my A/c working properly again?

[joshua43214]

so how much can i expect to pay to get my A/c working properly again?

For evac and recharge, expect to pay 1-1.5 huors labor and $45.00 or so a pound for R134a. So budget about $250.00 and you might get change. Every shop has its own protocol for this job, some will charge .5hr and just squirt in the stuff, most repudable places will do a fast sniffer check, try to spot any obviouse leaks and add some dye, so the any leak can be pinned down for sure at a later date. The dealer is as good as any place for this, they will charge more per labor hour, but you have the best chance of getting a competant person on the machine. They will be competive on the cost of R134a and might have a summer special running.

[Bill R.]

price for a case of 134a at costco or sams club right now is about 48 a case or 4 dollars a 12 ounce can. R12 is considerably higher than that.

For evac and recharge, expect to pay 1-1.5 huors labor and $45.00 or so a pound for R134a. So budget about $250.00 and you might get change. Every shop has its own protocol for this job, some will charge .5hr and just squirt in the stuff, most repudable places will do a fast sniffer check, try to spot any obviouse leaks and add some dye, so the any leak can be pinned down for sure at a later date. The dealer is as good as any place for this, they will charge more per labor hour, but you have the best chance of getting a competant person on the machine. They will be competive on the cost of R134a and might have a summer special running.

[joshua43214]

=), ya but most shops will not allow you to bring your own parts, and no one wants to be sucking a customers refrigerant out of those sucky little cans when they can just use the big bottle they got from NAPA that is strapped to the machine. I would always demand more time on an AC job if someone dumped those cans on me.

In my experience, folks that quibble over the price of an evac and recharge are the same folks that want free or cheap estimates so they can go home and do it themselves on other repairs. Often the same folks that want Saturday service or want to come after 5:00 PM, basicaly the worst customers, They go straight to the bottom of my priority sheet and they get the service performed when I finish the work that is feeding my family.