Timing Chain: Service and Repair

Timing Chain

To remove

1. Remove the Camshaft cover with gasket. Service and Repair

2. Remove the Timing cover. Service and Repair

3. Fit the crankshaft pulley.






4. Lower the car and zero the engine by turning the crankshaft in the direction of rotation of the engine until the marking on the crankshaft pulley is aligned with the marking on the timing cover. (A) The cam lobes on cylinder 1 intake and camshaft could be pointing up/in.






5. Remove the chain tensioner (A). Use 83 96 129 Oil filter tool, B207, and camshaft drive chain tensioner.






6. Remove the lock ring (A) from the chain tensioner and remove the piston.





7. Remove the plug (A) from the cylinder housing.

8. Remove the upper bolt (B) to the timing chain guide at the inlet side.

9. Remove the upper timing chain guide rail (C).





10. Remove the lower bolt (A) to the chain guide. Detach the lower section of the chain.

11. Remove the camshaft pinions (B). Use a wrench to grip the camshaft flats when the bolts are loosened. Lift up the chin.

12. Remove the tensioner guide (C) by lifting it up. Inspect the condition of the guide. Replace if necessary.


To fit

1. Clean all sealing surfaces.





2. Clean the camshaft and pinion contact surfaces (A) from oil and grease.





3. Fit the tensioner guide (A).

4. Lay the chain on the sprocket and lower the chain. Fit the sprocket on the camshaft and tighten the bolt (B).

5. Raise the car.

6. Fit the chain on the crankshaft sprocket and fit the chain guide. Fit the lower bolt (C).
Tightening torque 10 Nm (7 lb ft)

7. Lower the car.

8. Fit the exhaust sprocket and tighten the bolt (D).

9. Fit the upper bolt. Fit the plug on the cylinder head (E). F212R303





10. Turn the camshaft drive tensioner clockwise with a screwdriver until it engages in the tensioned position (A).





11. Place the plunger in the chain tensioner sleeve. Fit the circlip (A) and check that it is fitted correctly in the groove.

Note: Check that the O-ring and gasket are intact. If damaged, replaced the chain tensioner assembly.






12. Fit the chain tensioner.
Tightening torque 75 Nm (55 lb ft)






13. Release/activate the chain tensioner by carefully pressing on the timing chain or chain guide (as shown in the illustration). Use a screwdriver (A). Check that the tensioner has released.

14. Fit Timing cover. Service and Repair





15. Remove the exhaust camshaft and intake camshaft bearing caps no. 2 and no. 7. Position 83 96 046 Adjustment tool, camshaft (B207 150-175 hp) by manually pressing the tools down onto the camshafts without tightening the bolts. Rotate the camshaft until the tool aligns with the spanner on the camshaft flats. Tightening the adjustment tools' bolts (A).
Tightening torque 10 Nm (7 lb ft)




16. Check that the markings on the crankshaft pulley and the timing cover are aligned. Tighten the camshaft gears a first time. Use a wrench to grip the camshaft flats (A).
Tightening torque 30 Nm (22 ft lb)

17. Remove the adjustment tools and fit the bearing caps (B). F121R312
Tightening torque 8 Nm (6 lb ft)

18. Continue to tightening the camshaft gears to the final torque. Use a wrench to grip the camshaft flats (A).
Tightening torque 85 Nm + 30° (63 lb ft + 30°)

19. Turn the crankshaft 2 rotations in the engine's direction of rotation until the markings on the crankshaft pulley and the timing cover are aligned. Remove the bearing caps and refit 83 96 046 Adjustment tool, camshaft (B207 150-175 hp) and 83 96 079 Adjustment tool, camshaft (B207 210 hp) to check that the camshaft setting is correct. Remove the adjustment tools and fit the bearing caps.
Tightening torque 8 Nm (6lb ft)

20. Fit the upper timing chain guide rail (C).

21. Fit the Camshaft cover with gasket. Service and Repair

22. Lower the car completely.

23. Check engine oil level. Top up as necessary.