So I turned on my 2008 Sahara's AC this weekend, and noticed that it is pretty loud. Not like belt squeaking loud, but mechanically loud. I'm used to Toyotas and Hondas where you pretty much just hear an almost undetectable low hum when the ac is working. You can definitely notice that the A.C. is on in this thing, and it gets louder when I press the gas. Is this normal? Oh, and the noise seems to fade after a minute or 2, but still when I started the A.C. it alarmed me. I did see in the car fax that the dealership did replace the A.C. compressor right before I got it, so I figure it's a brand spanking new unit. How do your A.C.'s sound?

 

typically a Loud A/C unit means the Oil and / or refrigerant charge is incorrect.. Loud and then quieting down tends to make me think the compressor Oil charge is off.. it is banging the valve plates and then once refrigerant flow is established it gets oil into the right parts of the system... both low and high OIL charge (Not the same as the refrigerant!!!!) will make a compressor loud, so I cant tell you which way to go..

Oil is to be measured system wide so often times when a compressor is replaced the whole system is not flushed of all its oil and therefore improper amounts of oil are installed with the compressor...
-Christopher

 

Thanks for the info. I guess I will have the dealer check it on the next oil change as I really don't need the A.C. right now. I tried it again yesterday and right when the A.C. comes on it is loud, and it stays like that for a minute, then the noise will disappear. A minute later it is back on, then back off. It repeats this until I turn off the A.C. The air seems cold, but it's not exactly hot outside so I really can't tell if its actually working right.

 

The compressor should not be loud. You may hear the fan on your radiator running with the A/C on though, and that can be loud.

 

as the last post said make sire you arent just hearing your engine fan, it will have a fan / wind blowing / roaring sound..

a noisy compressor will come and go as the A/C in our jeeps cycles on and off.. the compressor turns off when the air is cold enough and turns back on when the air is not cold enough.. this cycle in a mild day (ie 65-75) outside will likely be on for a minute.. off for 30 seconds, on for a minute, off, etc.. this is normal operation..

if the sound is rattly, raspy, squealy or ratcheting (sewing machine) type of sound then the compressor is not running correctly..
-Christopher

 

I'm taking her into the dealership tomorrow. I opened the hood to look and the noise only comes on when the clutch actually engages. Sounds like I have a aftermarket turbo kit installed or something, lol. When the rpm's go up the sound rises in pitch too. They just put the compressor in last month (while it was the dealerships jeep and they were trying to sell it, saw it on the car fax) so hopefully it is fixed with out too much trouble.

 

Cycling on and off is normal.

It will make more noise when the A/C clutch engages. If it's an old pump, sometimes they rattle and whine a little bit.

The cooling fans in the engine will activate to move air about the A/C condensor, creating even more noise.

There's also next to nothing for insulation or noise cancelling in the engine bay. The Rubicons have an insulating pad under the hood, but that's it, so it's going to sound louder than your typical small economy car.

Let us know what the dealer says!

 

Thanks for the info. I'll let u guys know what they say. Let's just say it was loud enough for me with the freedom panels of to make me turn it off immediately in fear of breaking something. It's no small sound and never heard another vehicle make a sound like it with the ac on.

 

A/c clutch bearing.

 

with the AC or defroster on, I can here it clutch in, and the fan is a bit loud, however the AC pump is not loud at all.