Do you need a Torx socket for a Mercedes idler pulley?
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 pulley. Park your Mercedes-Benz in an area where you can work.
What’s the best way to replace an idler pulley?
You can use a nail or a 5mm Allen wrench as a pin. Slide the serpentine belt off the idler pulley. It is not necessary to remove the serpentine belt completely unless you are replacing it. Use a flathead screwdriver to remove the dust cap on the center of the idler pulley.
Where is the idler pulley on a Mercedes?
Pull the hood release under the dashboard on the driver’s side. Remove the engine cover by lifting it. Locate the idler pulley at the front of the engine. Remove the serpentine belt. Use a 17mm socket and ratchet on the tensioner nut to unload the tensioner.
What happens if you have a bad idler pulley?
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 the vehicle. Power steering is difficult to turn. The alternator stops working and no longer charges the battery. Air Conditioner stops working. Engine stalls once the battery is drained.
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 pulley. Park your Mercedes-Benz in an area where you can work.
What should I torque my idler pulley to?
Using a torque wrench (and a socket to keep the pulley from spinning if needed), torque the pulley bolt to 40 ft/lb. Set the wrench to 40 ft/lb and apply pressure to the bolt with the wrench until it clicks and you know you’ve hit the required torque.
How much does it cost to change a Mercedes idler pulley?
Average cost to change Mercedes-Benz idler pulley yourself is under $50 USD. [toc] 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 the vehicle.
Can a idler pulley be removed from an alternator?
To remove the drive belt, first release the tension to the belt. If your idler pulley attaches to the alternator, you will have to remove the bolt attaching the pulley to the alternator and push the entire alternator down to relieve the tension on the belt.