How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Marty Your Own Question
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53014
Experience:  Bosch Certified Master Tech. Over 35 years experience.
Type Your Mercedes Question Here...
Marty is online now
A new question is answered every 9 seconds

2000 S500: serpentine belt..the auto tensioner..slack..idler pulley

Resolved Question:

how do I replace my serpentine belt on my 2000 S500. I need to get the auto tensioner to to give me enough slack. Also, according to the manual, the grooved portion of the belt runs OVER the narrow idler pulley at the top--is this correct?
Submitted: 7 years ago.
Category: Mercedes
Expert:  Marty replied 7 years ago.

Hi chasman, here's the procedure from the manual. If anything doesn't make sense let me know and I'll try to explain it.




1.1Remove fan shroud (2) with electric fan (1)
2Loosen and remove the poly-V-belt (3)

NOTE: For this step, swivel stud bolt (4) at tensioning pulley (5) in anti-clockwise direction Lock tensioning pulley with drift or pin (5 mm diameter ).


3Inspect belt pulley sections and tensioning device for damage and dirt
4Inspect the poly-V-belt (3)


5Mount the poly-V-belt (3), then tighten


  • Do not use belt wax or any similar products.
  • Start at tensioning pulley in the numbered sequence of the respective running diagram: Running diagram of poly V-belt
6Install fan shroud (2) together with electric fan



Marty and 2 other Mercedes Specialists are ready to help you