i just picked up a 99 xj sport with 158K on it. so far im looking forward to increase my knowledge on these wonderful vehicles. i do have a small problem hopefully its nothing to major. whenever i turn the heat on the car will idle high and then drop down. it will make a click sound near the a/c compressor for a second then rev back down. thoughts?

 

Normal. The idle will increase to compensate for the load the A/C compressor puts on the engine.