Valve spring, rear
| Valve spring, rear | 
| To remove | 
| Important | ||
| 
         Store all removed valve parts in the valve stand 83 93 787.  | 
      ||
| 1. | 
        Remove the
        
         Camshaft cover, rear, B284
        
         | 
      |
| 2. | 
        Remove the spark plugs.
         | 
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| 3. | 
        Remove the camshaft solenoid valve (695R) (A)
         
        
         | 
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| 4. | 
        Remove the camshaft position sensor (555R) (B).
         | 
      |
| 5. | 
        Rotate the engine so that the markings on the camshaft sprockets are visible (A), and the indentations align with the cylinder head. Use
        
         EN-46105 Adjustment tool
        
        as a gauge (the camshafts are now in their neutral position) (B).
         
        
         
        
         | 
      |
| 6. | 
        Fit
        
         EN-46106 Flywheel locking attachment
        
        (A).
         
        
         | 
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| 7. | 
        Mark the chain and camshaft sprocket so they can be refitted in the same position.
         | 
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| 8. | 
        Slightly loosen the bolts holding the camshaft sprockets (A). Counterhold using an open spanner on the camshaft flats (do not remove the bolts).
         
        
         | 
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| 9. | 
        Fit
        
         EN-46108 -2 Fixing tool
        
        to the camshaft chain on the intake side (B). Check that the tool grips the chain firmly.
         | 
      |
| 10. | 
        Fit
        
         EN-46108-1 Fixing tool
        
        to the camshaft chain on the exhaust side (C). Check that the tool grips the chain firmly.
         | 
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| 11. | 
        Tighten
        
         EN-46108 Fixing tool
        
        so that the chain is unloaded.
        
  | 
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| 12. | 
        Remove the camshaft sprocket bolts (D).
         | 
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| 13. | 
        Remove the sprockets from the camshafts (E).
         | 
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| 15. | 
        Lift out the camshafts (B) and note the rear marking on the camshafts.
         | 
      |
| 16. | 
        Remove the roller rockers and the hydraulic adjuster elements (A). Store them in
        
         83 93 787 Valve stand
        
        so they do not get mixed up.
        
  
        
         | 
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| 17. | 
        Fit
        
         EN-46110-eu Valve spring tool
        
        (A).
         
        
         | 
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| 18. | 
        Fit
        
         83 94 173 Air nipple for spark plug hole
        
        (A). Connect compressed air and put the piston and valves under pressure.
         
        
         | 
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| 19. | 
        Press down the valve plate (B) with
        
         EN-46110-eu Valve spring tool
        
        .
        
  | 
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| 20. | 
        Remove the valve cone with a magnet (A).
         
        
         | 
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| 21. | 
        Lift out the spring plate and valve spring (A).
         
        
         | 
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| To fit | 
| 1. | 
        Clean all parts and check contact surfaces and bearing surfaces for wear.
         | 
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| 2. | 
        Fit the valve spring and spring plate (A).
         
        
         | 
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| 3. | 
        Press down the valve plate with
        
         EN-46110-eu Valve spring tool
        
        .
         | 
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| 4. | 
        Fit the valve cone (A) using
        
         EN-46117 Fitting tool
        
        .
         
        
         | 
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| 5. | 
        Unload the valve and remove
        
         EN-46110-eu Valve spring tool
        
        .
         | 
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| 6. | 
        Disconnect the compressed air connection and remove the air nipple.
         | 
      |
| 7. | 
        Position the camshafts and use
        
         EN-46105-1 Adjustment tool
        
        to check that the camshafts are mounted at the correct angle.
         
        
         | 
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| 8. | 
        Fit the bearing caps as illustrated (markings on caps). Start where the cams point down and load the tappets.
         Tightening torque 10 Nm (7 lbf ft) 
  | 
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| 9. | 
        Check that the markings (A) on the chain match the markings on the sprockets.
         
        
         | 
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| 10. | 
        Fit the sprockets with chain on the camshafts. Tighten the bolts by hand (A).
         | 
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| 11. | 
        Remove
        
         EN-46108-2 Fixing tool
        
        (B).
         
        
         | 
      |
| 12. | 
        Remove
        
         EN-46108-1 Fixing tool
        
        (C).
         | 
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| 13. | 
        Tighten the bolts for both camshaft sprockets, counterholding with an open spanner on the camshaft flats (D).
         Tightening torque: 65 Nm (48 lbf ft)  | 
      |
| 14. | 
        Remove
        
         EN-46106 Flywheel locking attachment
        
        .
         | 
      |
| 15. | 
        Fit the camshaft position sensor (555R) using a new gasket (B).
         Tightening torque 10 Nm (7 lbf ft)  
        
         | 
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| 16. | 
        Fit the camshaft solenoid valve (695R) using a new seal (A).
         Tightening torque 10 Nm (7 lbf ft)  | 
      |
| 17. | 
        Fit the spark plugs.
         | 
      |
| 18. | 
        Fit the
        
         Camshaft cover, rear, B284
        
         | 
      |
