Greetz All While I am in the process of rebuilding the 2000 engine, I need to work on my current motivator. Four things about it are bothering me: Valve guides may be old - rapidly shaking vacuum gauge needle at idle (18-21 inches) and a blue puff of smoke only at start. Leaking rear main seal - well; it seems to be coming from there Vibration - jury is still out on that one... it could be related to point 4. Tinking sound... Now, I want to address each one... but the tinking is one that baffles me. I replaced the cam recently as well as the lifters. With the valve covers off, the rockers seem to be operating normally. Exhaust temps are all in the same ballpark.. I set the valve lash hot... and yet I am getting a very distinct "TINK" sound that I hear very clearly around cylinder 8 with an automotive stethoscope. Now it sounds distinct... but not really audible without the stethoscope. As far as I know, the only think there the could make such a noise is the cam slapping the bottom of a lifter... but the cam and lifters are new. Anything I can do short of yanking the intake ? It doesn't sound like a bearing; seems to be coming from higher up and a different sound. At worst, I may be living with this until the other engine is ready.