Chain Tensioner
The hydraulic chain tensioner is a common part shared with the N63 engine. The N74 engine has a chain tensioner for each cylinder bank. It is a hydraulic chain tensioner that acts on a tensioning rail. Each one is arranged within the chain track to save space.
The oil spray nozzles for timing chain lubrication are integrated in the chain tensioners.
NOTE:
Before removal, the chain tensioner must be fully retracted and secured with the special tool supplied for the purpose. Always follow the procedure in the repair instructions.