Thanks in advance for all the advice. I havew read many, many threads after doing a search and found many good possibilities for my m60 engine being noisey suddenly and wanted to provide a sample of the symptoms with a video of the actual engine sound. The video is on youtube.com and here is the link...It's has the sound and where the video was taken during that sound heard.

http://www.youtube.com/watch?v=m54s5SmC25k

The problem is I have lost power and idles rough always in the past day now and I have no fault codes per the CEL or FCX and the engine ticking, chattering is worrying me and I don't want to drive it at all since the engine noise it proportional to engine speed but no power in and gear(It's an Auto).

Here's the background of the 95 530i that I've had approx. 1 year. When I purchased it it had a rebuilt engine installed with less than 100 miles on it and ran good but I did not run it hard for 1500 miles to let the engine run-in. Over the past year, it has had intermittent rough idle and the CEL ON with the O2 Sensor code on Pass-side which I checked and okay but replaced anyway since the code re-appeared after reset. The O2 code continued to show on the CEL and I switched the (2) O2 sensors and the CEL continued to show the pass-side O2 sensor, so figured it was some kinda vacuum leak on that side of the engine. In the meantime, I've replaced the plugs(both Bosch platinum+4 and NGK's), coil packs, ICV and ECU and reset the electrical system by the batt terminal shorting method and been getting along with the intermittant rough idle at times ove the year but now it's too severe to continue driving and nothing is improving it yet. At different times of the year, in NC, it has exhibited a power loss problem(where the car revs but not much power to the wheels) but never this severe and never with the engine noise like this.

During the plug replacements I have noticed the 2 rear plugs, closet to the firewall, wet with oil each time(about 4 times I've checked checked them). Early on I would clean the plugs and re-install and it ran smoother so I thought I would research the problem and repair when time permitted(by replacing the valve cover gaskets).