I can't figure out what is wrong with my car. It's making a ticking/clattering sound in low rpms or when it comes back down. I've tore the engine apart and can't find the problem. I've checked the rod bearings-good, all the pulleys-good, replaced the PCP valve, put new plugs in, put oil treatment in and oil change, and octane boost. Still hearing the noise! Sounds like it's coming from the top back end of the motor. If anyone has any ideas I'd appreciate the help. Thanks!

here's a link to hear my car make the noise:
http://www.youtube.com/watch?v=FROvDzmEYsE

 

It's kinda hard to tell through the other background noise, but here are my thoughts... I have a 2.5, in a 2000 and I have been chasing the same noise. You might try some of these. I verified my oil pressure with a gauge, all is well. Changed to synthetic oil, and the noises seamed to get worse. Switched back to dino blood and the noises reduced slightly from the original. Ran thinner dino oil and no improvement. Added Sea-foam to the oil, and at first the noises went away. Then came right back... Then I put the other half of the Sea-Foam, into 1/2 tank of gas, and after 'bout 100 miles the noises have greatly reduced, so now I think that I have injector issues, instead of liter issues... But I could have both. Since the noises then cam back after a point, and indicated that the oil needed to be changed, could have been a sludge issue, and clogged oil passages to the injectors... I have been trying to figure these noise out for about 50k miles and nothing catastrophic has happened, so I haven't felt the need to tear into the motor! There is allot of info on Ticking/Lifter Noise/Sludge Monster, both in here and out in the big internet, but apparently each case is special!