OK, if the sound is coming from the passenger side that leaves quite a few possibilities. The passenger side is where all of your belt driven accessories are. I do not know of any common noises coming from that side of the car, and a technical service bulletin search came up empty. On that side of the car you have your alternator, AC compressor,water pump and PS pump driven by the drive belt. The timing chain is on that side of the car also. I would first check the oil level. If the oil level is low or very dirty that would cause the timing chain to make noise. Next I would carefully listen with either a mechanics stethoscope or a long screwdriver to each accessory. To listen with a screwdriver just put the metal end of the screwdriver on the engine and your ear on the end of the handle. This is a surprisingly effective method of pinning down a noise. Just be sure to avoid the belt. See if any of the accessories seem to be making more noise than the others. Based on your description of the noise I would suspect the water pump. If you can not pin anything down that way you may have to remove the belt and run it to see if the noise is gone. If the noise goes away you can turn each component by hand to see if they are noisy. If the noise is still there with the belt removed it may be the timing chain. Listen at the front of the valve cover with your screwdriver. If the noise is there you likely have a timing chain issue. Hopefully this will give you some help in pinning down your problem. Noises are one of the hardest things to figure out from a distance. If I have helped you please accept. If you have more questions please reply. Thanks for using JA.