How often should it be done? Ever 15k miles?
What is the purpose? I know mine has not been done in 40k miles atleast.
WHen the car is off and I push the gas, I can hear a metal on metal type sound from the throttle within the engine. Mine needs lubing!
What should I use? How do I do it? This is for 95 C280 with M104 motor. Do I have to remove the air intake crossover pipe? Please help, thanks. :p

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
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!)