W126 motor ticking

Hi all,

My '91 560 SEL is ticking enough to bother me. It has 101K miles and has been well maintained. Seems to be louder from the front, on the driver's side.

Is it already time to replace the hydraulic lifters??

It isn't terribly loud, but I notice it. The Benz mechanic I took it to for it's last oil change said he didn't notice anything out of the ordinary.

I'm running Castrol 10w-30 now (temp ranges have been 0-35 Farh. since December, but spring is near!). Should I move to a heavier weight?

Thanks in advance for any input!