Mike,

thanks for the rapid response. Yes it is a Volvo dealership the re-do the timing, and I forgot to mention that before they touch the timing, it was done poorly by my mechanic not the dealer...reason why it gave me a hint to tell the dealer to check the mark as well. But still wondering if the timing is over-advance or bad sensors.

If your suggestion points to the crankshaft sensor, will this part throw code to tell the ECU that there's something wrong w/ it?

My analysis if after all the diagnosis and still not finding the fix, I'm suspecting on the valve stems and guides that's causing the lifter noise. And I'm still on limbo trying to figure this out.

Thanks again.

chrisq