Evaluation of the degree of stretching of the timing chain of the M628 engine
1. The degree of stretching of the timing chain can be determined indirectly by the position of the pulley (2) accessory drive belt on intake camshaft (1).
2. Remove the right cylinder head cover (see illustrations Installation details of the cylinder head covers of the M682 engine (1 of 2) and Installation details of the cylinder head covers of the M682 engine (2 of 2)).
3. Remove the accessory drive belt (see Section Replacement of the auxiliary drive belt and elements of its tensioning mechanism).
4. Turn the engine in the normal direction (arrow) so that the intake camshaft (1) could be blocked with a rod (4), - thread the rod.
5. If the pulley (2) accessory drive belt when the shaft is locked (1) turns out to be displaced by more than 11°after TDC relative to the setting mark (3) (see the scale printed on the pulley), the timing chain must be replaced.
6. Installation is carried out in the reverse order.