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Hey guys, just thought I'd pose a question. What is the deal with AC compressors and the load on the engine? Just why do they 'kick' sometimes?

Every car I've ever own and been around has occasionally had that 'kick' when the AC is on. The engine gets smacked and its load increases even more, then everything goes back to normal. There doesn't seem to be a pattern either.
 

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As I understand it.... The A/C much like the A/C in your house has two modes of operation. Either its on or off. When its off just the fan is running to circulate the air, when the pressure/temp of the freon (or whatever they use now days), then the compressor turns on. Once the pressure/temp reaches desired settings the compressor turns back off. As the gas is compressed is removed energy (cools as energy is released).

The "kick" you feel and hear is the compressor cycling.
 

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Gonzo,
you are right. It is especially noticeable when engine is idling as compressor adds relatively large load.
 

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I have a question -- since the a/c button defaults to "on" when the engine is started, even in winter, does it hurt to keep it on during the winter? If it doesn't need to cool the car down does the compressor not run even though the button is on?
 

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Didn't realize it defaulted.
Are you sure?
Do you mean that if I turn it off, it will be on the next time I satrt the car?

Anyway the sensor is inside the car, so yes if the inside was hot enuf, 1 or 2 degrees warmer than the a/c was set for, it would come on.

BTW You SHOULD run your A/C in thw winter. MAybe once a wekkf for maybe 5 minutes.
The oil in a compressor is carried by the freon (or puron or whatever) and this should be freely circulated now and then.

Homer
 

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Plus it helps suck the moisture out of the interior 'cause we're all so hot and steamy and fog up the windows...:rolleyes:
 

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Funny re A/C and condensation (water) being released under vehicle - I'm seeing a lot of water drain when I park the car after the AC has been on for a while - in fact, none of my pastcars have had this much water drain out is anyone else noticing quite a bit of drainage? Thanks in advance..
 

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I thought it was more than usual, also
Well, that's good.
THe more humidity taken out the better, IMO.

Homer
 

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Running A/C in winter

According to PF manual, once/month, even in winter, for something like 10 km or 10 mintues or something, and run A/C plus heater (set to defrost) for quick windscreen drying.

I get water under the truck, and thought that all A/C units wet their pants when parked.
 

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A number of years ago, when AC became popular in Germany, i think it was Mercedes that recorded many AC faults! All of them were traced to lack of use! The AC's were off for winter months. It caused deterioration of seals and consequent loss of cooling medium. Easy fix - run AC at least once a week for several minutes.
 

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Something I noticed is that the AC drain hose that drips water when you park the car actually drips some of the water onto the intermediate exhaust pipe, causing a sizzling sound. I imagine this can't be too great for the exhaust pipe.
 

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I don't like to have the AC turn itself on. If I'm taking a short trip (which I hate, bad for the MO) then I don't want the AC to cycle for a short duration. I usually turn off the AC then the system, the next time I start the car, I just turn the fan switch and it comes back on where I left off.

By the way with the FAN off you don't get any fresh air... silly as in past cars it was nice on the HW not to have the fan on but also get some circ in the car. Anyway around this?
 

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Fresh air?

With the entire HVAC system off, hit the mode switch and with each push, it will cycle through the different blower (air only in this case) choices.

You will feel air coming in even though nothing is indicated (fans) as being on and the temperature settings work as well (to a degree).

I've been using this setting quite a bit with the cooler days we're having recently.

Gas mileage seems to be going up as well.
 

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Ah excellent... I'll give that a try tomorrow. Still getting through the break in period. Added some mileage tonight. Can't wait to be done with it so I can "drive normal" again. Love this car!
 
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