[FC] Synthetic oil...serious tapping

[Ben and Lynn Stiles]

Hello everyone-

I cahnged the oil in the 'Brier to Mobil 1 synthetic (10-W-40) before 
leaving for Iowa. All went well...until the second to last day when I 
started it up and such a racket!! IT was tapping like crazy. Well, we 
had to keep moving, so we did. It got quieter as it got warmer 
throughout the day. Got home with no issues. I just started it up again, 
and it is tapping plenty, though not as badly as that second to last day 
of vacation.

Should I be adding the ZDDP stuff anyway, even though I went with 
synthetic oil to avoid its use? Could I be having issues with the top 
end lifters?