Valve Tappets - Engine Installed

Removing and installing valve tappets - engine installed




Tools

Preliminary work for valve tappet removal

1. Disconnect battery.

2. Set up and secure convertible top compartment lid.

3. Remove top engine-compartment cover.

4. Remove left-hand seat.





5. Remove rear wall lining and rear wall cover Put on floor protection cover.

6. In vehicles with air conditioning, the following additional operations must be performed:





6.1 Remove drive belt. Mark the running direction of the belt with a colored pen. Relieve the belt tension. To do this, turn the tensioning roller (wrench size 24 mm) clockwise and simultaneously remove the belt from the drive pulleys.

6.2 Remove pulley of the hydraulic pump.





6.3 Undo the front compressor fastening screws (2 ea.) and disconnect the electrical plug connection.





6.4 Undo the compressor fastening screw between the intake pipes of cylinders 4 and 5.

6.5 Undo the B+ connection (box) on the engine and put it aside.





6.6 Suck out fluid from power steering reservoir until level is below the joint. Open bayonet lock and remove the reservoir. Close opening.





6.7 Lift the air-conditioning compressor with the connected lines out of the engine compartment and place on a wooden surface on the center tunnel or console.

7. Remove the rear wheels.

8. Remove right and left diagonal braces.

9. Remove rear support sheet.





10. Detach and remove exhaust manifold of cylinder head 4 - 6.

11. Unclip oxygen-sensor plug from the brackets of the rear-axle support.





12. Detach cable between engine and rear-axle support at the rear-axle support.





13. Detach rear-axle support and remove to the side.

14. Drain engine oil.

Removing valve tappets of cylinder bank 1 - 3





1. Move camshafts of cylinder bank 1 - 3 to basic position or removal position. Turn crankshaft clockwise until the bore 1 OT (top dead center) in the pulley is aligned with the fixing bore on the crankcase. Position or fix with fixing pin (short) of special tool 9595.

Note The basic camshaft adjustment can be checked only after removal of the camshaft closure caps.





2. Remove camshaft closure caps above the cylinder-head oil pumps. The closure cap of cylinder bank 1 - 3 is located on the flywheel side and the closure cap of cylinder bank 4 - 6 is located on the pulley side. Drive awl into center of the closure cap and lever off the cap.





3. Check basic camshaft adjustment of cylinder bank 1 -3.
The groove in the camshaft must face outward toward the cylinder-head cover.
If the position of the camshafts is incorrect, remove fixing pin at the pulley and rotate the crankshaft 360° clockwise. Then position or fix the fixing pin in the bore (1 OT) and in the fixing bore in the crankcase again.





4. Unscrew chain tensioner of cylinder bank 1 - 3.





5. Detach and remove oil extraction pump at cylinder head 1 - 3 - on the flywheel side.

6. Separate plug connection of the tensioning element (VarioCam).

7. Unscrew two hexagon-head bolts (M6 x 20) and remove closure cap from the tensioning element (VarioCam).

8. Remove ignition coils, spark plugs and oil protection tubes.

Note As the available space is limited, the oil protection tubes must be removed before the cylinder-head cover can be removed. Refer to "Removing and installing oil protection tube".





9. Remove the camshaft closure caps from the passenger compartment side. Drive awl into center of the closure cap and lever off the cap.





10. Fit special tool, holding-down device 9624, on the cylinder head. Fasten holding-down device with a hexagon-head bolt M8 x 30.

11. Remove cylinder-head cover. Loosen the hexagon-head bolts from the outside to the inside. Detach cylinder-head cover by tapping lightly with a plastic hammer.

12. Additionally fasten a holding-down device of special tool 9611 using M6 x 45 auxiliary screws.





13. Relieve camshaft tensioning element with special tool, tensioning screw 9632. Screw tensioning screw in only until the chain is slightly relieved.

14. Unscrew three fastening screws (M6 x 95) for tensioning element.





15. Affix auxiliary chain tensioner (screw in by approx. 3 turns). Undo four hexagon-head bolts (M6 x 15) on the chain sprocket. Remove auxiliary chain tensioner again.





16. Remove drive plate. Remove sprocket wheel and chain and connect with a tie wrap (installation position).

17. Detach bearing saddles and lever out of the guide sleeves.





18. Remove special tools, holding-down devices 9611 and 9624, and carefully lift the entire unit, consisting of camshafts with chain and tensioning element, out of the cylinder head. The chain must not jump over during this operation; reallocate if necessary.

19. Lift out valve tappets with a magnet.





20. Detach guide for valve tappets. Undo the pan-head screws (15 ea.) from the outside to the inside and remove the guide.

Installing valve tappets of cylinder bank 1 - 3

1. Check guide for damage. Refer to: Checking guide for valve tappets.

2. Fit guide. Tighten pan-head screws (M6 x 35) from the inside to the outside. Tightening torque: 10 Nm (7.5 ft. lbs.)

3. Lightly oil the valve tappets and fit in the guide.

4. Lay the complete unit, camshafts with chain and tensioning element, into the cylinder head. The groove or tab of the camshaft position sensor cover must face outward in installed position.





If the allocation should be uncertain, e.g. chain jumped over, reallocation is necessary. Refer to: Completing camshafts.

5. Fasten special tool, holding-down device 9611, with auxiliary screws M6 x 45.





6. Fit special tool, holding-down device 9624, on the cylinder head using a hexagon-head bolt M8 x 30.





7. Check dowel sleeves (4 ea.) of the bearing saddles to ensure that they are properly seated in the cylinder head. Oil bearing surface. Fit bearing saddles in the correct position and tighten evenly. Tightening torque: 10 Nm (7.5 ft. lbs.)

8. Fit tensioning element (VarioCam). Tighten 3 M6 x 95 pan-head screws. Tightening torque: 10 Nm (7.5 ft. lbs.).

9. Unscrew tensioning screw, special tool 9632, from the tensioning element.

10. Remove tie wrap and fit sprocket wheel with chain on the flange of the exhaust camshaft.

11. Position drive plate or driver star on the sprocket wheel. Fit hexagon-head bolt M6 x 15 (10.9). Tighten hexagon--head bolt by hand only.





12. Unscrew chain tensioner (fitted on the crankcase half of cylinder bank 4 - 6) and fasten auxiliary chain tensioner (special tool 9599). Fit auxiliary chain tensioner without sealing ring and fasten on the crankcase only hand-tight. The mechanical auxiliary chain tensioners must be installed with the correct pre-tension when the valve timing is adjusted or checked. The necessary pre-tension force has been reached when the measuring pin is flush with the face surface of the thrust screw. Turn the screw if necessary.





13. Fit auxiliary chain tensioner on cylinder head 1 - 3 and adjust pre-tension force (refer to step 12).





14. Fit cylinder-head cover. Remove holding-down device 9611. Clean sealing surface of the cylinder head and cylinder-head cover very carefully. Apply bead of silicone on the cylinder-head cover. Refer to: Sealing cover for camshaft housing (cylinder-head cover).
Carefully place the cylinder-head cover in the correct position so that the sealing bead is not damaged. Screw two studs or centering pins into the corners of the cylinder head as centering aids. Tightening torque: 13 Nm (10.0 ft. lbs.)
Immediately remove silicone material emerging in the area of the camshaft closure cap.





15. For the subsequent adjustment work on the camshaft, the pulley must be fixed at bore 1 OT (TDC) with the fixing pin (special tool 9595).





16. Fasten blocking device (special tool 9612) on the cylinder head.

Special-tool fitting sequence:





A - Fastening screw with star knob on the cylinder-head lug.
Pull back centering piece (B) and sword bolt (C) when tightening.
B - Centering piece in groove of the exhaust camshaft. Pull back sword bolt (C) when tightening.
C - Sword bolt





17. Allocate camshafts; to do this, turn the pre-tensioned center piece accordingly until the sword bolt can be fixed in the bearing bore.

18. Fasten sprocket wheel. Tightening torque: 14 Nm (10.5 ft. lbs.)

19. Remove blocking device.

Note The auxiliary chain tensioners must remain fitted on cylinder bank 4 - 6 for the subsequent assembly work.

20. Fit oil extraction pump.

Note The oil extraction pumps on the cylinder heads are identical parts. Therefore, the installation position or direction of rotation must be correct.





Installation position of oil extraction pump at cylinder head 1 - 3 (flywheel side): The arrow for the direction of rotation or the marking "1 - 3" must face the crankcase. Fit oil extraction pump. Use new sealing ring and new micro-encapsulated hexagon socket head screws. Tightening torque: 10 Nm (7.5 ft. lbs.).

21. Fit camshaft closure cap dry.

22. Fit closure cap on tensioning element (VarioCam). Tightening torque: 10 Nm (7.5 ft. lbs.).

Removing valve tappets of cylinder bank 4 - 6





1. Remove fixing pin. Turn crankshaft 360° clockwise until the bore 1 OT (top dead center) in the pulley is aligned with the fixing bore on the crankcase. Position or fix with fixing pin (short) of special tool 9595.





2. Check camshaft adjustment at cylinder bank 4 - 6: The groove in the camshaft must face inward toward the crankcase.





3. Unscrew chain tensioner of cylinder bank 4 - 6.





4. Detach and remove oil extraction pump at cylinder head 4 - 6 (pulley side).

5. Separate plug connection of the tensioning element (VarioCam).

6. Unscrew two hexagon-head bolts (M6 x 20) and remove closure cap from the tensioning element (VarioCam).

7. Remove ignition coils, spark plugs and oil protection tubes.

Note As the available space is limited, the oil protection tubes must be removed before the cylinder-head cover can be removed. Refer to: "Removing and installing oil protection tube".

8. Remove the camshaft closure caps from the underside of the vehicle. Drive awl into center of the closure cap and lever off the cap.





9. Fit special tool, holding-down device 9624, on the cylinder head. Fasten holding-down device with a hexagon-head bolt M8 x 30.

10. Remove cylinder-head cover. Loosen the hexagon-head bolts from the outside to the inside. Detach cylinder-head cover by tapping lightly with a plastic hammer.

11. Additionally fasten a holding-down device of special tool 9611 using M6 x 45 auxiliary screws.

12. Relieve camshaft tensioning element with tensioning screw, special tool 9632. Screw tensioning screw in only until the chain is slightly relieved.

13. Unscrew three fastening screws (M6 x 95) for tensioning element.

14. Affix auxiliary chain tensioner (screw in by approx. 3 turns). Undo four hexagon-head bolts (M6 x 15) on the chain sprocket. Remove auxiliary chain tensioner again.





15. Remove drive plate. Remove sprocket wheel and chain and connect with a tie wrap for the subsequent installation position.

16. Detach bearing saddles and lever out of the guide sleeves.





17. Remove special tools, holding-down devices 9611 and 9624, and carefully lift the entire unit, consisting of camshafts with chain and tensioning element, out of the cylinder heads. The chain must not jump over during this operation; reallocate if necessary.

18. Lift out valve tappets with a magnet.





19. Detach guide for valve tappets. Undo the pan-head screws (15 ea.) from the outside to the inside and remove the guide.

Installing valve tappets of cylinder bank 4 - 6

1. Check guide for damage. Refer to: Checking guide for valve tappets.

2. Fit guide. Tighten pan-head screws (M6 x 35) from the inside to the outside. Tightening torque: 10 Nm (7.5 ft. lbs.)

3. Lightly oil the valve tappets and fit in the guide.





4. Lay the complete unit, camshafts with chain and tensioning element, into the cylinder head. The groove or tab of the camshaft position sensor cover must face outward in installed position. If the allocation should be uncertain, e.g. chain jumped over, reallocation is necessary. Refer to: Completing camshafts.

5. Fasten special tool, holding-down device 9611, with auxiliary screws M6 x 45.





6. Fit special tool, holding-down device 9624, on the cylinder head using a hexagon-head bolt M8 x 30.





7. Check dowel sleeves (4 ea.) of the bearing saddles to ensure that they are properly seated in the cylinder head. Oil bearing surface. Fit bearing saddles in the correct position and tighten evenly. Tightening torque: 10 Nm (7.5 ft. lbs.)

8. Fit tensioning element (VarioCam). Tighten 3 M6 x 95 pan-head screws. Tightening torque: 10 Nm (7.5 ft. lbs.)

9. Unscrew tensioning screw, special tool 9632, from the tensioning element.

10. Remove tie wrap and fit sprocket wheel with chain on the flange of the exhaust camshaft.

11. Position drive plate or driver star on the sprocket wheel. Fit hexagon-head bolt M6 x 15 (10.9). Tighten hexagon-head bolt by hand only.





12. Fit auxiliary chain tensioner, special tool 9599, on cylinder head 4 - 6. Fit auxiliary chain tensioner without sealing ring and fasten on the crankcase only hand-tight. The mechanical auxiliary chain tensioners must be installed with the correct pre-tension when the valve timing is adjusted or checked. The necessary pre-tension force has been reached when the measuring pin is flush with the face surface of the thrust screw. Turn the screw if necessary.





13. Fit cylinder-head cover. Remove holding-down device 9611. Clean sealing surface of the cylinder head and cylinder-head cover very carefully. Apply bead of silicone on the cylinder-head cover. Refer to: Sealing cover for camshaft housing (cylinder-head cover).
Carefully place the cylinder-head cover in the correct position so that the sealing bead is not damaged. Screw two studs or centering pins into the corners of the cylinder head as centering aids. Tightening torque: 13 Nm (10.0 ft. lbs.)
Immediately remove silicone material emerging in the area of the camshaft closure caps.





14. For the subsequent adjustment work on the camshaft, the pulley must be fixed at bore 1 OT (TDC) with the fixing pin (special tool 9595).





15. Fasten blocking device (special tool 9612) on the cylinder head.





Special-tool fitting sequence:

A - Fastening screw with star knob on the cylinder-head lug. Pull back centering piece (B) and sword bolt (C) when tightening.
B - Centering piece in groove of the exhaust camshaft. Pull back sword bolt (C) when tightening.
C - Sword bolt





16. Allocate camshafts; to do this, turn the pre-tensioned center piece accordingly until the sword bolt can be fixed in the bearing bore.
17. Fasten sprocket wheel.

Tightening torque: 14 Nm (10.5 ft. lbs.)
18. Remove blocking device.

19. Fit oil extraction pump.

Note The oil extraction pumps on the cylinder heads are identical parts. Therefore, the installation position or direction of rotation must be correct.





Installation position of oil extraction pump at cylinder head 4 - 6 (flywheel side): The arrow for the direction of rotation or the marking "4 - 6" must face the crankcase. Fit oil extraction pump. Use new sealing ring and new micro-encapsulated hexagon socket head screws. Tightening torque: 10 Nm (7.5 ft. lbs.)

20. Fit camshaft closure cap dry.

21. Fit closure cap on tensioning element (VarioCam). Tightening torque: 10 Nm (7.5 ft. lbs.)