Does the M113 have cam oilers that go bad?

The tick tick sound started one day (that I noticed it), so I'm thinking something broke.

I hear the noise when the car is idling, but not when I'm running a normal driving speeds.

Your thoughts and suggestions are appreciated.

2002 W210 M113 E430
Miles: 107,000

I did just change the spark plugs, and after that is when I noticed the sound.

The sound concerns me, but the car accelerates nice and smooth, with no other symptoms.

__________________
Thanks for the help
Bill Fisher

'86 560SL (186K) - Now a 'classic' : Registered as an Historic Vehicle
02 E430 in the stable
'14 LS460 (Lexus)
- - - - -
'95 E420 (198K) found a new home
'99 E320 (80K) (gave it's life for me as we hit a bumper)
'95 E420 (231K) Sold to a happy buyer, new to Mercedes
'90 300E (65K) Sold to an Mercedes Lover
'92 190E (215K) - retired to the salvage yard
'93 500SEL (214K) - Moved to another family, still runs like a young pup