I have the vehicle noted and started having issues with a clacking sound coming from the front of the engine. I took off the valve cover to discover my timing guides and followers were breaking apart. The timing chains were also severely worn and stretched. Thought this may be the issue. (Note: micro aluminum shavings throughout the engine had resulted) Nope. Changed everything in the timing compartment from the chains, sprockets and guides etc. Slapped it all back together and still makes the racket. Checked the valves and they are all doing their jobs, as well as the rockers. The lobes on the cam shafts (overhead cams btw) are in constant contact. Oil is being ejected properly. The clacking has upgraded to a clack and squeak (metallic sounding). I should have prefaced with the fact that this sound is NOT a constant. It does fade slightly and return. Top front right under intake man. seems to be the most generalized location I can provide. Input?