A rattle type noise may be noted from the AC compressor or the compressor could be damaged due to "slugging" of the refrigerant. The compressor may require replacement to correct this concern. If the compressor is replaced an updated condenser may also be required.Google+
Car Problem Reports
Jeep Patriot Abnormal Noise or Damage to AC Compressor
Jeep Patriot Problem
Average Mileage: 96,666 mi (55,000 mi - 130,000 mi)
Visitor, 2008 Jeep Patriot, 55,000 mi
Rattling noise understand hood..... Closer inspección revealed noise coming from AC compressor.
Visitor, 2007 Jeep Patriot, 105,000 mi
Recently started hearing a rattle under hood, changed out a few pulleys and nothing changed. Took the vehicle to a few mechanics, two of them said it was the ac compressor. Other simply said it was a pulley on the engine, but we had already changed those. With inspections, the compressor was not disengaging when the ac is turned off. So basically the compressor runs non-stop when the vehicle is on causing me to lose power and have low gas mileage. I was told to get this changed out as soon as possible because if it locks up more it will burn the belt off causing more damage to the components under the hood. So now the hunt begins on finding the right price for replacement and the mechanic with ac gauges to do the repair.
Visitor, 2008 Jeep Patriot, 130,000 mi
Noise when the AC is on and the cars is in R and N