I'm sure its normal, but what is that clicking coming from the engine. In park you can hear a periodical click, then the rpm goes up about 50, a second later it clicks again and the rpm goes back. it looks like a belt right at the front that turns off and on.....? is this for the heater or ac? it is quite annoying.......

 

From the description you provided, it sounds as if your a/c condensor is cycling. This can be remedied by trying a different setting on your instrument panel.

First,determine where your heater/ac setting is currently. Then, try different settings tofind one prevents the ac condensor cycling.

Hope this helps.

 

I agree. Your a/c is cycling on and off based on your temp setting. Defrost mode will also kick the a/c on.

 

defenitely is the clutch on ur a/c compressor engaging and disengaging. if it happens when the heater/AC is off then u may have a bad compressorclutch.

 

this even happens when the ac is off? I pretty much never use my ac. The heat is always full blast and it still does this.......

what is a compressor clutch and is it pricey to repair? If it goes unattended will it mess other things up too?

 

If it is indeed your A/C compressor cycling, that is a completely normal thing. When the a/c kicks on, the IAC (idle air control) valve opens up to increase RPM a bit to compensate for the extra draw on the engine...

 

Like Hanr3 said, the A/C compressor cycles in defrost mode also.

 

Maybe I should explain a little more.
I dont know when, however GM set the HVAC system up so that when you trun on the defrost (heat) the a/c will also come on. This accomplishes several things, all good. Prior to this a/c units would start to leak due to lack of use, the o=ring would dry out and the freon owuld leak out. The biggest advantage is the reason for a/c. A/C removes moisture from the air, that is how it cools the air. Hone, office, or truck it doesnt matter all a/c units do the same thing, remove water from teh air. In the winter heat wil not clear the windows of moisture quick enough. Heat only will first have to literaly cook the moisture ut of hte air, you will get hot long before that happens, your clothes will ahve to completely dry, even the puddle of water on the floor from your feet will ahve to dry. Like ahnging wet socks next to a fire, takes a long time to dry.

With the a/c unit on it draws the moisture out much faster then the heat will cook it out.

What I am trying to say, is that GM set up all HVAC systems so that when in defrost mode, the a/c unit kicks on to clear the windows. There are only 1 or 2 settings on your HVAC controller where the a/c is not on. If you have the owners manual, pull it out and read it, mine covers this pretty well.

 

oh! i just learned something, thanks everyone. I thought maybe it wasmalfunctioning. My Dad also said that the A/C circulates the "ac oil" to lube it all up........

So if one was never to use there ac, or defrost setting, the whole system would sieze up?

 

It will only sieze up if you loose all the freon. By not using the a/c at least once per month the o-rings dry out and you develope leaks in the system, eventually you will loose all the freon due to the leaks. however in the meantime your a/c wont blow cold.