Thanks for the info John! I really appreciate it.
The reason I ask this is because I have a slight rattle from the engine bay when the car is idling, and only when idling. I can't find the exact location of it. I have checked everything for looseness, replace a few clips (for radiator and 2-fan shroud). Didn't solve problem... and I *think* that it's louder when the oil cap is off. Would that make sense? Thanks again!
2006 E350 w/ 155k miles (Daily Driver)
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)