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Mercedes Idler Pulley Replacement Instructions

This article provides step-by-step instructions and a video on how to change the Mercedes idler pulley.

A common problem with Mercedes-Benz cars is the idler pulley (also known as Guide Pulley or Sheave Pulley), failing as early as 100,000 miles.

Mercedes Idler Pulley Replacement Instructions
ESTIMATED TIME 1-2 hr
DIY COST $20-$50
DIFFICULTY Intermediate

Changing the idler pulley on a Mercedes-Benz is a relatively easy for most DIYers and requires less than two pulley on a Mercedes-Benz is a relatively easy for most DIYers and requires less than two hours.

Symptoms

A bad idler pulley can cause the serpentine belt to come off. Once the belt comes off, you will experience multiple problems if you continue to operate thpulley can cause the serpentine belt to come off. Once the belt comes off, you will experience multiple problems if you continue to operate the car.

  • Power steering is difficult to turn.
  • The alternator stops working and no longer charges the battery.
  • Battery warning light on the dashboard
  • Air Conditioner stops working.
  • Engine Overheats
  • Engine stalls once the battery is drained.

At the early stage, indicating that the idler pulley is failing, you will only hear a squeaky noise coming from the engine's front. Inspect the idler pulley if you hear noise from the epulley is failing, you will only hear a squeaky noise coming from the engine's front. Inspect the idler pulley if you hear noise from the epulley if you hear noise from the engine.

The noise can be described as whining. Remove the serpentine belt and check the idler pulley for play or noise by spinning it bypulley for play or noise by spinning it by hand.

It would be best if you replaced a bad idler pulley immediately to avoid future problems caused by complete idler pulley fapulley immediately to avoid future problems caused by complete idler pulley fapulley failure.

What you will need

Note that the older models of Mercedes-Benz engines require a Torx Bit Socket. This is common on M112 and M113 engines from 1997 to 2007.

Newer Mercedes-Benz idler pulleys (on M272 and M273 and newer models) require a Female Torx socket. Always verify by inspecting the bolt on the center of your idler pulleypulley.

Procedure

  1. Park the Mercedes-Benz in an area where you can work. If the idler pulley fails while driving, it is possible to change it on the road. You need to make sure you are working in a safepulley fails while driving, it is possible to change it on the road. You need to make sure you are working in a safe area.
  2. Allow the engine to cool down for at least thirty minutes.
  3. Pull the hood release under the dashboard on the driver's side.
  4. Remove the engine cover by lifting it. Locate the idler pulley at the front of the epulley at the front of the engine.remove engine cover

     

  5. Remove the serpentine belt. Use a 17mm socket and ratchet on the tensioner nut to unload the tensioner. release tensioer to replace mercedes idler pulley
  6. Use a pin to lock the tensioner in the pre-loaded position. You can use a nail or a 5mm Allen wrench as a pin. 
  7. Slide the serpentine belt off the idler pulley. It is unnecessary to remove the serpentine belt completely unless you are replacipulley. It is unnecessary to remove the serpentine belt completely unless you are replacing it.mercedes removing belt from idler pulley
  8. Use a flathead screwdriver to remove the dust cap on the center of the idler pulley. Do NOT discard the dust cap. It needs to be reinstpulley. Do NOT discard the dust cap. It needs to be reinstalled.
  9. Use a T-50 Torx to remove the idler pulley bolt. The bolt is long and requires patience to remove. Some models require a female Torx spulley bolt. The bolt is long and requires patience to remove. Some models require a female Torx socket.change mercedes drive belt idler pulley
  10. Install the new idler pulley and tighten the bolt to Mercedes-Benz specificapulley and tighten the bolt to Mercedes-Benz specifications.
  11. Install the dust cap.
  12. Turn the idler pulley by hand to make sure it is spinning fpulley by hand to make sure it is spinning freely.
  13. Reinstall the serpentine belt. If the belt is not long enough to slide over the tensioner pulley, make sure it sits properly in all the pulleys.mercedes idler pulley and serpentine belt installation
  14. Use your 17mm socket and ratchet to move the tensioner upward to remove the locking pin.
  15. Slowly load the tensioner.

Torque Specifications

Typical Mercedes-Benz idler pulley bolt topulley bolt torque:

  • Newton-meters 35 Nm
  • Foot-pounds: 25.81 ft-lb

These torque specs may vary between models. We recommend that you verify the correct torque specs by calling your Mercedes-Benz dealer. 

Notes

  • It is recommended (not required) to change the tensioner while you change the idler pulleypulley.
  • If your vehicle has a viscous fan, it may need to be removed to access the idler pulley. Common on pre-2000 mpulley. Common on pre-2000 models.

Part Numbers

Below you will find part numbers for some of the most common Mercedes-Benz idler pulleys.

MODELS PART NUMBERS
  • 2005-10 Chrysler 300 V6 3.5L
  • 2005-10 Chrysler 300 V6 2.7L
  • 2004-08 Chrysler Crossfire Idler PulleyPulley
  • 2009-10 Dodge Challenger V6 3.5L
  • 2006-10 Dodge Charger V6 3.5L
  • 2006-10 Dodge Charger V6 2.7L
  • 2005-08 Dodge Magnum V6 2.7L
  • 2005-08 Dodge Magnum V6 3.5L
  • 2003-06 Dodge Sprinter Van Idler PulleyPulley
  • 2007 Mercedes Benz C230 Idler PulleyPulley
  • 2001-05 Mercedes Benz C240 Idler PulleyPulley
  • 1998-00 Mercedes Benz C280 Idler PulleyPulley
  • 2001-05 Mercedes Benz C320 Idler PulleyPulley
  • 1998-00 Mercedes Benz C43 AMG Idler PulleyPulley
  • 2000-06 Mercedes Benz CL500 Idler PulleyPulley
  • 2001-02 Mercedes Benz CL55 AMG Idler PulleyPulley
  • 1998-05 Mercedes Benz CLK320 Idler PulleyPulley
  • 1999-02 Mercedes Benz CLK430 Idler PulleyPulley
  • 2003-05 Mercedes Benz CLK500 Idler PulleyPulley
  • 2001-05 Mercedes Benz CLK55 AMG Idler PulleyPulley
  • 1998-05 Mercedes Benz E320 Idler PulleyPulley
  • 1998-02 Mercedes Benz E430 Idler PulleyPulley
  • 2003-05 Mercedes Benz E500 Idler PulleyPulley
  • 1999-02 Mercedes Benz E55 AMG Idler PulleyPulley
  • 2002-05 Mercedes Benz G500 Idler PulleyPulley
  • 1998-03 Mercedes Benz ML320 Idler PulleyPulley
  • 2003-05 Mercedes Benz ML350 Idler PulleyPulley
  • 1999-01 Mercedes Benz ML430 Idler PulleyPulley
  • 2002-05 Mercedes Benz ML500 Idler PulleyPulley
  • 2000-03 Mercedes Benz ML55 AMG Idler PulleyPulley
  • 2000-06 Mercedes Benz S430 Idler PulleyPulley
  • 2000-06 Mercedes Benz S500 Idler PulleyPulley
  • 2001-06 Mercedes Benz S55 AMG Idler PulleyPulley
  • 1999-06 Mercedes Benz SL500 Idler PulleyPulley
  • 2001-04 Mercedes Benz SLK320 Idler PulleyPulley

0002020919,

000 202 09 19 04593848AA

04792836AA 68020888AA

Engines:

M112 and M113

  • 2008-2009 MERCEDES-BENZ C230 4MATIC SEDAN 4-DOOR
  • 2008-2009 MERCEDES-BENZ C230 BASE SEDAN 4-DOOR
  • 2006-2007 MERCEDES-BENZ C230 SPORT SEDAN 4-DOOR
  • 2010-2010 MERCEDES-BENZ C250 4MATIC SEDAN 4-DOOR
  • 2010-2010 MERCEDES-BENZ C250 BASE SEDAN 4-DOOR
  • 2009-2010 MERCEDES-BENZ CL550 4MATIC COUPE 2-DOOR
  • 2007-2008 MERCEDES-BENZ CL550 BASE COUPE 2-DOOR
  • 2006-2009 MERCEDES-BENZ CLK350 BASE CONVERTIBLE 2-DOOR
  • 2006-2009 MERCEDES-BENZ CLK350 BASE COUPE 2-DOOR
  • 2007-2009 MERCEDES-BENZ CLK550 BASE CONVERTIBLE 2-DOOR
  • 2007-2009 MERCEDES-BENZ CLK550 BASE COUPE 2-DOOR
  • 2007-2010 MERCEDES-BENZ CLS550 BASE SEDAN 4-DOOR
  • 2007-2007 MERCEDES-BENZ E280 4MATIC SEDAN 4-DOOR
  • 2007-2007 MERCEDES-BENZ E280 BASE SEDAN 4-DOOR
  • 2008-2009 MERCEDES-BENZ E300 4MATIC SEDAN 4-DOOR
  • 2006-2011 MERCEDES-BENZ E350 4MATIC SEDAN 4-DOOR
  • 2006-2009 MERCEDES-BENZ E350 4MATIC WAGON 4-DOOR
  • 2011-2011 MERCEDES-BENZ E350 4MATIC WAGON 4-DOOR
  • 2011-2011 MERCEDES-BENZ E350 BASE CONVERTIBLE 2-DOOR
  • 2010-2011 MERCEDES-BENZ E350 BASE COUPE 2-DOOR
  • 2006-2011 MERCEDES-BENZ E350 BASE SEDAN 4-DOOR
  • 2006-2006 MERCEDES-BENZ E350 Base WAGON 4-DOOR
  • 2011-2011 MERCEDES-BENZ E350 BLUETEC SEDAN 4-DOOR
  • 2010-2011 MERCEDES-BENZ E350 ELEGANCE SEDAN 4-DOOR
  • 2010-2010 MERCEDES-BENZ E350 SPORT SEDAN 4-DOOR
  • 2007-2011 MERCEDES-BENZ E550 4MATIC SEDAN 4-DOOR
  • 2011-2011 MERCEDES-BENZ E550 BASE CONVERTIBLE 2-DOOR
  • 2010-2011 MERCEDES-BENZ E550 BASE COUPE 2-DOOR
  • 2007-2011 MERCEDES-BENZ E550 BASE SEDAN 4-DOOR
  • 2009-2011 MERCEDES-BENZ G550 BASE SPORT UTILITY 4-DOOR
  • 2007-2011 MERCEDES-BENZ GL450 BASE SPORT UTILITY 4-DOOR
  • 2008-2011 MERCEDES-BENZ GL550 BASE SPORT UTILITY 4-DOOR
  • 2010-2011 MERCEDES-BENZ GLK350 4MATIC SPORT UTILITY 4-DOOR
  • 2010-2011 MERCEDES-BENZ GLK350 BASE SPORT UTILITY 4-DOOR
  • 2006-2011 MERCEDES-BENZ ML350 4MATIC SPORT UTILITY 4-DOOR
  • 2009-2011 MERCEDES-BENZ ML350 BASE SPORT UTILITY 4-DOOR
  • 2010-2011 MERCEDES-BENZ ML350 BLUETEC 4MATIC SPORT UTILITY 4-DOOR
  • 2010-2011 MERCEDES-BENZ ML350 SPORT AMG SPORT UTILITY 4-DOOR
  • 2008-2011 MERCEDES-BENZ ML550 BASE SPORT UTILITY 4-DOOR
  • 2006-2011 MERCEDES-BENZ R350 4MATIC WAGON 4-DOOR
  • 2008-2011 MERCEDES-BENZ R350 BASE WAGON 4-DOOR
  • 2010-2011 MERCEDES-BENZ R350 BLUETEC 4MATIC WAGON 4-DOOR
  • 2009-2009 MERCEDES-BENZ S450 4MATIC SEDAN 4-DOOR
  • 2007-2011 MERCEDES-BENZ S550 4MATIC SEDAN 4-DOOR
  • 2007-2011 MERCEDES-BENZ S550 BASE SEDAN 4-DOOR
  • 2007-2011 MERCEDES-BENZ SL550 BASE CONVERTIBLE 2-DOOR
  • 2009-2011 MERCEDES-BENZ SLK300 BASE CONVERTIBLE 2-DOOR
  • 2005-2011 MERCEDES-BENZ SLK350 BASE CONVERTIBLE 2-DOOR

A272 202 10 19

supersede

A2722020000

2722021019

A2722021019

Engines:

M272 and M273

 

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Great instructions. Thank you for your help.

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Mercedes Idler Pulley Replacement Instructions This article provides step-by-step instructions and a video on how to change the Mercedes idler pulley.

A common problem with Mercedes-Benz cars is the idler pulley (also known as Guide Pulley or Sheave Pulley), failing as early as 100,000 miles.