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Adjusting the Tensioner Pulley

Model: Mercedes Classe M W163 - Years 1997-2005
Part: V-belt

If you hear a squeaking noise from the front of the engine while it is running, it may be caused by a pulley driven by the auxiliary belt. To confirm, loosen the tensioner and remove the belt, then start the engine for a few seconds. Once you identify the noisy pulley, in this case, the tensioner pulley, remove it and check the condition of the bearing. After removing the shield, you will notice a complete absence of grease. Clean the bearing balls with some penetrating spray, then apply grease and refit the seal. Once everything is reassembled, start the engine and check that the noise has disappeared.

Updated on 19 February 2026 by ScegliAuto

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