This guide is applicable to V6, V8, and V12 Mercedes-Benz engines found on C-Class, E-Class, S-Class, ML-Class, G-Class, GL-Class, R-Class, and other models.
What you will need
- Open the hood and remove the engine cover by pulling it up in order to access the crankshaft.
- Remove the air intake hoses.
- Remove the camshaft position sensors. Some models have two camshafts position sensors on the intake and two on the exhaust side.They are held in place with Torx bolts, which require E Torx Sockets to be removed.
- Place the 27mm socket on the crankshaft bolt.
- Turn the crankshaft clockwise until the 305-degree mark on the main pulley lines up with the mark on the engine case. The 305 stamps are printed on the pulley. Keep rotating the crankshaft clockwise until the 305 stamp comes up to the top.
- Next, check the stamps on the camshaft by looking through the camshaft position sensor hole. Check all. On a good engine that has no timing chain, guide rails, sprocket wear, the stamp should all be on the center of the hole.
- If one of the stamps is off-center, your Mercedes-Benz timing is off. The problem could be due to a stretched timing chain, chain sprocket, timing chain guides, weak tensioner, etc.
This guide applies to many Mercedes-Benz models, including W204, W211, W221, 906, S211, W212, W251 V251, W203, S212.