Malfunctioning motor mounts can cause a lot of damage to your engine, drastically reducing its service life. Clunking noises caused by the engine, while driving your Mercedes Benz vehicle, is a sign that you should inspect and possibly replace the motor mounts. Motor mounts that are functioning poorly can increase the shock endured by an engine while driving, or may crack completely and allow the engine to fall, which may require engine replacement. Mercedes Benz motor mounts, of which there are usually two, generally have a rubber or polyurethane coating.
Step 1
Pop the hood of your Mercedes Benz to inspect the motor mounts. Common causes of malfunction include loose or fractured mounts. Reference the service manual for your model of Mercedes Benz for more specific instructions on locating the motor mounts. If the mounts are simply loose, you may only need to tighten them.
Step 2
Set up a hydraulic jack underneath the engine of your car. Lift the engine of your Mercedes Benz with the jack until the stress has been removed from the motor mounts.
Step 3
Check the flexible joint on your Mercedes Benz motor mounts for operational quality. Joints on motor mounts may become inflexible over time, reducing the mounts' ability to secure the engine without transferring physical shock while the vehicle is in motion. With the pressure relieved from the mounts, you can check the flexibility of each motor mount's rubber-coated joint with a screwdriver. Use your screwdriver to poke the rubber coating on the motor mount and note if the coating has any give to it. If the rubber is inflexible, the mount must be replaced.
Step 4
Remove the motor mounts from your Mercedes Benz. Use a socket wrench and an appropriately-sized bit to remove the bolt securing the mounts to both the engine and other fixtures in the car hood. Some mounts can be removed through the top of the hood while others may need to be removed from underneath due to fixtures blocking the mounts from above.
Step 5
Install your replacement motor mounts into the car hood of your Mercedes Benz. Mounting bolts will be included in the replacement motor mount packaging. Secure the motor mounts by tightening bolts in the appropriate locations with your socket wrench and wrench bit.
Release the hydraulic jack slowly to lower the engine of your Mercedes Benz. Close the car hood.
Items you will need
Hydraulic jack
Mercedes Benz service manual (if necessary)
Screwdriver
Socket wrench and wrench bits